Smallpox of chickens (smallpox-diphtheria) (Variola gallinarum) is a contagious, predominantly chronic disease of birds of the suborder chicken, caused by a typical pathogen of the genus Avipoxvirus. Smallpox in chickens is accompanied by conjunctivitis and the formation of focal specific exanthema and enanthema, more often in the head and upper respiratory tract.

History reference... The disease has been known since ancient times under various names. Previously, smallpox of birds was considered not as a single disease, but as two independent diseases, diphtheria and smallpox. Later, given that smallpox is a more characteristic and specific form of lesion, and its causative agent is generally close to smallpox viruses, this disease in birds began to be called smallpox. Smallpox is ubiquitous in foreign countries (USA, Canada, South America, Asia and Europe).

Economic damage... Bird smallpox causes great economic damage to the poultry industry. The annual losses caused by chickenpox in France were estimated at 200 million. francs, in Holland the share of smallpox accounts for 12% of total losses in poultry farming. The disease causes a sharp decrease in egg production up to 5 times, deterioration of the results of egg incubation. The damage in poultry farming is aggravated by the fact that, having appeared once in a herd, it later became due to the high persistence of the virus, stationary, repeated annually and accompanied by a high percentage of morbidity and mortality. In the USSR, before the introduction of preventive prophylaxis in a number of poultry farms, the death from this disease reached 25-30% of the poultry population.

Etiology... The viral etiology of chickenpox was established by F.P. Polovinkin (1902). Prior to this, Bollinger (1873) discovered specific intraplasmic inclusions in the epithelial cells of the skin of patients with birdpox. A. Borel (1904) identified elementary bodies (virions) of the virus, known as Borel's little bodies. Inclusions. discovered by Bollinger and named later by the little bodies of his name, are clusters of tens of thousands of virions, and their identification has diagnostic value. The virus is filtered through the Berkefeld V suppositories and the Seitz plate, but does not penetrate through the Berkefeld W and N suppositories. The virus is able to penetrate the collodion membrane with pores of 0.3 in size, but does not pass through the pores of 0.25. According to some data, the particle size of avian pox virus is 120 t / h, and according to others, 125-175 t / h. The virus is resistant to physical and chemical influences. In poultry houses, the virus survives up to 158 days, and on down and up to 182 days. Under normal atmospheric conditions, the dried virus can be more active for up to two years. In diffused light, it retains its infectivity at 0-6 ° C for months, and in some cases for about a year or more. At 60 ° C, the smallpox virus dies in an hour, and at 80 ° C for 15-30 minutes, boiling kills it in 6 minutes. At low temperatures (-190 ° C), it remains viable for several days.

The virus loses its infectivity in 1% acetic acid and 1% mercuric chloride after 5 minutes, in 0.1% mercuric chloride after 20 minutes. He also perishes in a 3% solution of carbolic acid, in a 0.5-1% solution of formalin, a weak solution of iodine (1:10 000), a 2.5% solution of sulfuric and hydrochloric acids. Glycerin, even at 25 ° C, slowly neutralizes the virus (within 12 days).

When a virus is exposed to a 1% solution of caustic potassium, a solution of acetic acid in the same concentration, a solution of mercuric chloride 1: 1000, it is quickly inactivated. The virus dies when exposed for 10 minutes to 70 ° and 96 ° ethyl alcohol, at a temperature of 20 ° and within 30 minutes when exposed to 50 ° alcohol. In practical conditions, veterinary specialists have to use a 1-2% solution of caustic alkali (caustic soda) for disinfection. Disinfection with caustic alkali dissolved in 5% milk of lime is even more reliable.

Epizootic data... Smallpox disease in birds is caused by the introduction of infection into the farm from the outside, as well as by a virus that persists for a long time in the farm itself. If you do not carry out proper veterinary and sanitary measures and thorough disinfection, then smallpox can become a stationary infection and occur at any time of the year. An adult bird gets sick more often and more heavily during molting, in autumn and winter. The most sensitive to smallpox are young animals and birds of decorative breeds, in which the disease occurs in diphtheroid and mixed forms. In adult birds, damaged skin is the gateway for the virus and therefore the cutaneous form of smallpox predominates.

The source of infection is a sick and recovered bird (within 2 months after the illness), eggs contaminated with the smallpox virus, down and feathers, soil, food, water, inventory and overalls of the service personnel.

Infection occurs both through direct contact of a healthy bird with a sick bird, and through infection with the virus of care items, feed, through service personnel, and also through the bites of blood-sucking insects. In mosquitoes and mosquitoes that attack a bird sick with smallpox, the virus can persist for about 210 days, in a fly-flies for 20 days, in a Persian tick for 30 days, in ornithodorus for 97 days, in bedbugs for 35 days. Domestic and wild birds and rodents are also carriers of the smallpox virus.

It was also found that in the warm season and in countries with hot climates, birds usually have a skin form, and in winter, a diphtheroid form, when the process of damage to the mucous membrane occurs more often. This fact is explained by a lack of vitamin A, a violation of mineral metabolism and other factors that reduce the body's resistance. Under these conditions, the virus also penetrates through the intact mucous membrane. Poultry sick with smallpox and virus carriers release the virus into the environment with falling off virus-containing crusts and films; faeces and discharge from the nose, mouth and eyes, as well as laid eggs.

Smallpox outbreaks usually occur in the form of enzootics, and sometimes epizootics. The bird is ill with smallpox for 6 weeks or more. Under unsatisfactory conditions of keeping and feeding birds, up to 50-70% of the birds die. In a sick bird, egg production decreases 5 times or more, which, after recovery, recovers slowly, hatchability of chickens during illness and for a long time after the chickens recover from illness remains low and often amounts to about 20-25%. A bird that has been ill for a long time loses its natural resistance and becomes more sensitive to other microflora.

Depending on the virulence of the virus strain, the ways of its penetration into the body, the age and physiological state of the bird's body, the incubation period ranges from 4 to 20 days.

Pathogenesis... The smallpox process is generalized, with the most pronounced lesions occurring in the epithelial tissue of the skin and mucous membranes (crest, beard, body skin, mucous membrane of the oral cavity and pharynx).

After contact with the smallpox virus on the damaged skin of the ridge or beard, smallpox exanthema occurs in chickens, and when it enters the skin follicles, smallpox folliculitis. The smallpox process can spread to large areas of the skin or mucous membranes at the sites of application of the virus and take a generalized course. With a generalized course, the smallpox virus is found in the blood, liver, kidneys, ovaries, in the brain and other organs and tissues of the bird.

The severity of the smallpox process in a sick bird depends both on the resistance of the infected bird and on the virulence of the virus that has entered the body, and on the secondary microflora, which usually complicates the smallpox process.

For a bird with smallpox, the most dangerous lesion is the mucous membrane of the larynx. Due to the participation of bacteria from the cocci group, necrosis sticks and other microorganisms in it, this lesion has the character of diphthyritic plaques, films, overlays that impede breathing and feeding of the bird, and in some cases cause complete blockage of the laryngeal gap and death of the bird from suffocation.

Clinical signs... On the skin at the base of the beak, eyelids, on the ridge, beards and other parts of the body, round, first pale yellow, and then reddish spots appear, gradually turning into small nodules. These nodules often coalesce, and after a few days their surface becomes covered with a serous sticky exudate that dries up to a reddish-brown crust. If the smallpox proceeds without complications, then after 7-10 days, the smallpox disappears without leaving noticeable scars. An accumulation of serous exudate is noticeable under the removed scab.

Pockmarks in chickens are usually not poured out at the same time. On the 17-19th day after infection, a secondary smallpox process sometimes occurs on previously unaffected areas of the skin. Diphtheritic inflammation of the conjunctiva of the eyes in birds causes lacrimation, photophobia, swelling of the eyelids, mucopurulent discharge from the eyes, followed by the formation of a crust that sticks the eyelids together. Sometimes smallpox in birds is accompanied by the formation of keratitis, and with a complication of microflora - panophthalmitis. In some cases, corneal perforation and complete destruction of the eye occurs. The general condition of a sick bird is depressed, feathers are ruffled, appetite is poor or
missing.

With diphtheroid and mixed forms, a rash appears in the form of whitish, opaque, several raised nodules on the mucous membrane of the mouth, tongue, nose, larynx, trachea, bronchi, accessory cavities (sometimes under the cuticle of the stomach and on the intestinal mucosa). They, rapidly increasing in size, often merge with each other, become yellowish and contain a cheesy necrotic mass or resemble a film tightly connected to the submucous layer. If these fibrin-like overlays (films) are removed, bleeding erosions are formed. Diphtheroid overlays make breathing difficult, so birds often have an open mouth and make whistling or wheezing sounds when breathing.

Pathological changes, most characteristic in the skin and mucous membrane, reflect one form or another of smallpox disease. When the pockmarks are cut, they find a greyish-yellow fatty mushy mass inside them. Pockmarks in birds differ from those in mammals by the absence of typical pustules with a depression in the center. If pathological changes are localized in the infraorbital sinuses, then the latter are protruded in the form of tuberous eminences. Sometimes similar changes are found in the walls of the air sacs and intestines. Autopsy of birds that died during the acute course of smallpox reveals an enlargement of the spleen, edema in the lungs, punctate hemorrhages on the serous membranes, on the epicardium, and small foci in the liver that have a yellowish color.

In the histological examination of smallpox lesions, changes are found in the epithelial tissue in the form of a thickening of the epidermis layer due to the increased multiplication of these cells. The cells become enlarged and swollen, they have Bollinger bodies near the nucleus, which are colonies of the virus in the lipoprotein envelope. Their size can be different, and such inclusions occupy most of the cell. Bollinger bodies give positive histochemical reactions for DNA, fat, phosphatases. They are well impregnated with silver nitrate when processing sections according to the proposed method of V.M. Apatenko (1964), and also well detected in crushed sections after staining with Sudan 3.

Diagnosis based on the analysis of epizootological, clinical data, pathological changes and the results of laboratory studies, including histo studies, viroscopy, RDP, bioassay with identification of the virus on EC, FEC cultures, chickens and pigeons, electron microscopic studies.

Differential diagnosis... Smallpox is differentiated from chickens, rhinitis of chickens, candidiasis,. It should be borne in mind that some of them can occur simultaneously, including with smallpox.

Forecast favorable only for uncomplicated cutaneous smallpox (which is rare), if smallpox lesions are localized only on the head. In the diphtheroid form, the prognosis is poor. The percentage of death of birds largely depends on their age, condition, conditions of keeping and feeding. In some poultry houses, 10 to 70% of birds die. A particularly large mortality is observed among young animals with smallpox, complicated by secondary microflora. Keeping poultry that has recovered from smallpox, especially laying hens, is unprofitable.

Immunity and specific prophylaxis... In a vaccinated healthy (as well as in a recovered) bird, immunity is formed, especially intense in the stage of non-sterile immunity, and it is produced both for the homogeneous chickenpox virus and the heterogeneous pigeonpox virus, although the latter is less intense. A clinically healthy animal is immunized with a virus vaccine.

All clinically healthy birds belonging to the population living in a dysfunctional economy or a threatened area are also vaccinated.

Prevention and control measures... In smallpox-free farms, measures are taken to prevent the introduction of the pathogen of smallpox and to increase the resistance of the poultry organism. Especially carefully these measures should be carried out by persons working on the farm and having birds in their personal backyard. All imported birds must be quarantined, and they must be constantly monitored by veterinarians.

When a diagnosis of chickenpox is established in a farm, the farm is declared unfavorable for poultry smallpox by the Decree of the Governor of the region and quarantine is imposed. The farm conducts activities in accordance with the instructions on measures to combat smallpox of birds. Approved by the Main Directorate of Veterinary Medicine of the USSR Ministry of Agriculture on September 14, 1970.

According to the terms of quarantine, it is prohibited to:

1) export of poultry of all ages and species, including the sale of chickens to the population (except for export for slaughter to meat processing enterprises).

Note. In some cases, provided that the incubation workshop is reliably isolated from poultry houses (poultry farms) that are unsatisfactory for smallpox and other measures are taken to prevent the spread of infection, by decision of the veterinary department of the regional (regional) department of agriculture, the ministry of agriculture of the autonomous republic, the main department (department) of veterinary medicine The Ministry of Agriculture of a union republic, which does not have a regional division, is allowed to export day-old chickens, turkey poults, guinea fowls, goslings and ducklings to specialized poultry farms within the respective region (territory), republic;

2) export of eggs for breeding purposes.

According to the conditions of quarantine, it is allowed:

• the sale of eggs through the distribution network immediately after their disinfection in the manner prescribed by the current rules;
• incubation of eggs obtained from birds of safe poultry houses for the purpose of reproduction within the same farm, provided that the eggs are disinfected immediately before laying in the incubator;
• import of waterfowl, as well as chickens, pheasants, peacocks, turkeys and guinea fowls vaccinated against smallpox (20 days after vaccination).

In a farm dysfunctional for smallpox:

a) when a smallpox disease appears among poultry, all sick and suspicious of the disease, as well as weak poultry, must be slaughtered at the sanitary slaughterhouse of the given farm.

The export of such poultry for slaughter to meat processing enterprises is prohibited.

The rest, conditionally healthy poultry that do not have clinical signs of the disease, taking into account economic feasibility, is also recommended to be killed for meat or taken to meat processing plants. In the latter case, the export of poultry is permitted subject to the conditions stipulated by the Rules for Veterinary Examination of Slaughter Animals and Veterinary and Sanitary Examination of Meat and Meat Products.

Post-mortem veterinary and sanitary examination and sanitary assessment of meat are also carried out in accordance with the specified Rules. At the same time, the export of carcasses obtained from the slaughter of sick poultry suitable for use in food is allowed only after heat treatment. It is not allowed to sell such carcasses without preliminary heat treatment also inside the farm.

Note. When slaughtering large quantities of poultry in poultry farms or meat processing enterprises, with the permission of the veterinary department of the regional (regional) administration of agriculture, the ministry of agriculture of the autonomous republic, the main administration (administration) of veterinary medicine of the ministry of agriculture of the union republic, which has no regional division, the carcasses are taken out to the nearest food enterprises within the respective oblast (krai), republic for use in the public catering network.

b) all clinically healthy birds are immunized against smallpox with pigeon virus vaccine, according to the instructions for its use. The vaccinated bird is monitored and, if within 20 days after vaccination, patients with smallpox (from those vaccinated in the incubation period) stand out among them, then they are killed and proceed as indicated in subparagraph "a".

c) for preventive purposes, poultry is also vaccinated on farms threatened by the introduction of smallpox into them (including birds in the personal use of citizens);

d) feathers, fluff obtained during the slaughter of a sick and suspicious bird, are disinfected by immersion in an alkaline solution of formaldehyde (3% formaldehyde in 1% sodium hydroxide solution) with an exposure of 1 hour and taken to processing plants in a container with a double packing with an indication in the veterinary certificate of the form No. 3-vet (veterinary reference 4-vet) about the trouble of the smallpox farm;

e) carry out thorough mechanical cleaning, as well as disinfection, disinsection and deratization of premises, equipment, inventory and production territory in the manner prescribed by the instructions for conducting veterinary disinfection, disinfestation, disinsection and deratization; the droppings after removal from the poultry houses are subjected to biothermal disinfection; poultry houses are kept clean and dry at all times, avoiding crowded poultry;

f) the poultry is provided with complete feed, it is recommended to add dairy products to the diet.

At meat processing plants and at procurement points, when smallpox is detected, all poultry is slaughtered, while quarantine is imposed at the time of slaughter and health measures. The import of newly arrived poultry into them is allowed after the sale of all poultry products and the implementation of veterinary and sanitary measures (mechanical cleaning, disinfection, disinsection, deratization).

Quarantine from a dysfunctional economy is removed 2 months after the elimination of the disease (the last case of revealing clinical signs of smallpox in birds) and the final disinfection.

The export of grown chickens and adult poultry to other farms for picking is allowed no earlier than 6 months after the quarantine is lifted.

In former dysfunctional farms, after the elimination of the disease, prophylactic universal vaccination against smallpox is carried out for all birds susceptible to this disease for two years.

Smallpox is not uncommon in chickens and quickly takes on the dimensions of an epidemic, causing significant damage to farms. Not all birds are treated, sick animals are slaughtered, and measures are being taken to combat the spread of the virus. We will learn about chicken pox, what kind of disease it is, how it spreads, signs and diagnostics, how to deal with it and whether it can be cured.

What is this disease

Smallpox in chickens is contagious viral disease... It mainly affects areas of the body without feathers (legs, head, mouth and respiratory organs, mucous membranes of the eyes).

History reference

Smallpox was first described in 1775 as contagious conjunctivitis. In 1902, scientists determined that diphtheria and skin lesions are manifestations of the same disease. After a while, the Germans determined its viral origin. In the 1930s, research divided smallpox in chickens, pigeons, and canaries.

Economic damage

Smallpox of chickens is widespread throughout the world and causes significant damage to the poultry industry in many countries. With this disease, there is a strong decrease in the productivity of birds - egg production is significantly reduced (by 5 times), hatchability of chicks (up to 80% perish).
Sick chickens lose weight, die, and are discarded. A bird that has recovered takes a long time to recover. The causative agent of smallpox is very persistent, and the epidemic often repeats itself more than once. Quarantine and disinfection takes a lot of money.

Before the introduction of these measures in the USSR, smallpox killed up to 30% of the chicken population, but even now this problem is urgent.

Did you know? Holland annually loses from smallpox to 12% of poultry, and the French suffer losses of up to 200 million francs.

Causative agent

Smallpox disease occurs due to infection with a virus from the family Avi poxviridae, genus Avipoxvirus. This viable organism remains at temperatures up to 38 ° for 8 days, and at temperatures up to 6 ° - up to 8 years.

Subzero temperatures contribute to its even greater safety. He continues to live on down and feathers for 195 days, on eggshells - 59 days. The virus dies from the rays of the sun in 11 hours and in a few minutes under the influence of acids and alcohol. But in the aquatic environment, he can live for about 66 days.

Sources and routes of infection

Infection can enter the house with sick or recovered birds, including wild birds, as well as with rodents through their feces.
Insects that come into contact with birds, bedding, eggs, feed, water, contaminated clothing of workers and various household items in the poultry house that have become infected can also serve as a source of infection. The smallpox virus passes through mucous membranes and skin lesions.

The mechanism of the onset and development of the disease

The causative agent of smallpox, getting on the damage to the epidermis, forms smallpox folliculitis. On the beard and comb, it forms exanthema smallpox. The course of the disease depends on the state of the bird's immune system, on the virulence of the virus strain.

Avitaminosis, metabolic disorders, the presence of secondary microflora aggravate the course of the disease. It often takes a generalized form, when, within 24–48 hours, it is spread by blood to many organs, in which, under its influence, dystrophy of parenchymal cells and changes in vascular endothelial cells appear.

Severe damage to the larynx can clog it, and the bird will die.

Forms and signs

Symptoms of smallpox disease in chickens depend on the form and severity of the disease. There are three forms of smallpox: cutaneous, diphtheria and mixed.

Dermal

With this form, pockmarks appear on non-feathered areas (usually in the head area), starting from the 4th day from the ingress of the virus. First of all, attention is drawn to the lesions on the catkins, crest, beard, near the eyes and at the beak.
They first look like yellowish specks, which then turn red and degenerate into warts. They can be up to 0.5 cm in size and are covered with scabs. After a few days, they acquire a brown tint.

The formation of pockmarks can take 1–2 weeks, and the disease itself lasts about 6 weeks. The cutaneous form has the most favorable prognosis.

Did you know? The mortality rate of chickens with the skin form of the disease is not higher than 8%, and with diphtheria it reaches 50%, or even 70% (in the presence of unfavorable factors). The mixed form usually takes 30-50% of the lives of the inhabitants of the house. Young animals die most of all from smallpox.

Diphtheria

It is the most severe form of smallpox and affects the mouth, larynx, trachea, and esophagus.

It is characterized by the following symptoms:

• the presence of ulcers in the oral cavity;
• heavy breathing, wheezing, coughing;
• stretching the neck;
• open beak;
• loss of appetite and refusal to eat;
• purulent nasal discharge;
• purulent swollen lesions around the eyes;
• photophobia;
• swelling of the eyelids and increased tearing.

Mixed

This form manifests itself as symptoms of both of the above forms. With it, both the skin and mucous membranes are affected.

Diagnostics

Collect and analyze epizootological and clinical data. An autopsy is performed on a dead or sick bird sent for slaughter. Analyzes for histological studies and virus isolation, viroscopy, RBP are taken and carried out.

Important! Smallpox symptoms are very similar to other diseases common in chickens. Symptoms of smallpox disease are similar to hypovitaminosis A, infectious rhinitis, laryngitis, tracheitis and bronchitis, scab, aspergillosis, candidiasis, respiratory form of mycoplasmosis, pasteurellosis and others.

Research is being conducted to rule out the presence of these diseases. It should be borne in mind that these diseases can occur with smallpox at the same time.

Pathological changes

The most noticeable varying degrees of damage to the skin and mucous membranes. In the cut pockmarks, a greyish-yellow greasy gruel is observed. Usually the conjunctiva and the eyes themselves are also affected.

Sometimes the disease is localized in the eye area (infraocular sinuses), which begin to bulge, or in the walls of the air sacs, esophagus, intestines and stomach.
During the postmortem examination of chickens who died from the acute course of the disease, there is a strong emaciation of birds, an increase in the size of the spleen, swelling of the lungs, small foci of yellowish tints in the liver, epicardium and serous membranes contain punctate bloody blotches.

The intestinal mucosa is loose, stained and may have hemorrhages. With a chronic course of the disease, smallpox may not be found. But there will be a degeneration of internal organs (liver, kidneys, heart) and an increase in the spleen.

The histology of pockmarks shows a thickening of the layers of the epidermis. The cells are swollen and contain Bollinger bodies, which is a direct confirmation of the disease.

How to treat smallpox in chickens

Treat rationally the skin form with a mild course of the disease. In other cases, chickens are slaughtered. Skin lesions are treated with emollient ointments, and ulcers are treated with 1% iodine-glycerin, 3-5% chloramine solution. The nasal cavity and eyes are washed with lukewarm boiled water, and then irrigated with a 3% boric acid solution.

Did you know? Chickens sick with smallpox can infect any poultry belonging to the order of chickens - turkeys, pheasants, quails, guinea fowls. Even ostriches are susceptible to this disease.

Instead of the latter, you can use a chamomile solution. Potassium iodide is diluted in drinking water. An antibiotic may be prescribed to prevent secondary infections. One of them is Paracillin at a dosage of 1 g per liter of boiled water for a week. The body of birds is strengthened by the intake of vitamins.

Is quarantine necessary in case of mass destruction

Smallpox is a resistant disease. In the event of a mass disease of chickens with smallpox, the farm announces quarantine, and it is classified as dysfunctional. In such a farm, measures are taken in accordance with the current sanitary and veterinary standards for the fight against smallpox.

The standards in the case of quarantine are as follows:

1. You can not take chickens out of a dysfunctional economy. Only export for slaughter is allowed. In some cases, when the premises and areas for keeping are in good isolation from poultry houses susceptible to smallpox, and the farm has taken all measures to prevent the spread of the virus and infection, then, by the decision of the relevant veterinary services, it is possible to take day-old chicks to poultry farms and farms within area.
2. It is forbidden to take out eggs for breeding to the tribe. Sale of eggs is possible after appropriate disinfection.
3. Stop the import of poultry that are completely healthy and vaccinated. On dysfunctional smallpox farms, all poultry with signs of the disease are sent for slaughter on the territory of the farm. It is prohibited to export such poultry to meat processing plants. The rest of the bird is also recommended to be slaughtered or put for processing. Such export of chickens is allowed subject to all sanitary and veterinary standards. The carcasses of slaughtered birds are examined accordingly. It is possible to export and sell inside the farm after slaughtering poultry infected with smallpox only after heat treatment.
4. All healthy birds are vaccinated against smallpox. If, after being vaccinated for 3 weeks, the chickens show signs of the virus, then they are sent for slaughter. All poultry is vaccinated against smallpox also in farms in which there is a threat of the appearance of this virus.
5. Feather and down after slaughter of a bird susceptible to the disease is treated with a 3% formaldehyde solution and 1% sodium hydroxide solution for one hour. Only after that they can be exported to other enterprises in containers with reinforced double packaging, indicating in the veterinary documents that the raw materials are from a dysfunctional smallpox economy.
6. It is necessary to thoroughly disinfect all household premises, equipment and inventory, as well as the entire site in accordance with veterinary norms and recommendations. Chicken droppings are treated with biothermal disinfection.

Quarantine from poultry farms is removed only 60 days after the complete elimination of the virus and all final disinfection measures. It will be possible to take out the grown chickens to other farms only six months after the end of quarantine. In former dysfunctional farms, they have been carrying out prophylaxis in the form of vaccination of the entire population of chickens for 2 years. If, after 2 years, no signs of the onset of the disease have been identified, then further vaccination is not required.

Is it dangerous for humans

Smallpox is not dangerous for humans. On poultry farms, when this diagnosis is detected, chickens are handed over for slaughter, and the meat must be boiled, only the head is removed. The meat of the heavily affected poultry is disposed of. Eggs cannot be used for incubation.

They are suitable for food use after boiling, but they are usually not eaten.

Vaccinations are the most effective preventive and treatment measure for birds. They are especially relevant for chickens of valuable breeds.

Two types of vaccines are used for vaccinations:

• with the presence of a chicken virus;
• with the presence of the pigeon virus.

Such drugs are used to develop immunity against smallpox in chickens, chickens, turkeys, ducks. With this vaccination, an injection is made into the membrane located under the wing. Chickens are vaccinated once and for life at the age of 1–3.5 months.
Broiler chickens are vaccinated at 28 days. Within 7-10 days, a reaction in the form of redness and slight swelling appears at the puncture site during vaccination. She says that the immunization procedure was carried out correctly. Redness and swelling disappear within 14-21 days.

Important!You need to buy an effective vaccine and properly vaccinate. Some smallpox epidemics in chickens are caused by incorrect vaccinations. An incorrect vaccination or an unusable vaccine will be indicated by the absence of a reaction to the vaccine in the form of redness. True, such a lack of reaction can also be in already vaccinated individuals.

General preventive measures

To prevent smallpox in chickens, experts recommend taking the following preventive measures:

• ventilate the chicken coop well, but without drafts;
• maintain dryness, cleanliness in the room, regularly change the litter;
• carry out timely cleaning and disinfection of the premises, equipment;
• to fight rodents, exclude contact with wild birds;
• make sure that the chickens do not huddle together;
• decontaminate garbage and droppings in accordance with the existing sanitary and veterinary standards;
• to remove quarantine from farms no earlier than 60 days after the elimination of smallpox and the final disinfection;
• to vaccinate against smallpox all birds on farms unfavorable for this disease, within a certain period after the elimination of the epidemic. The same measure is carried out in farms that are located in areas that are unfavorable for this disease.

Smallpox is a contagious disease in birds that cannot always be cured. In the farms where it is found, a long quarantine is announced and measures are being taken to eliminate it. In most cases, sick chickens and birds in contact with them are sent for slaughter. The best measure for smallpox is vaccination.

The optimal solution for combating ailments is prompt effective prevention. For preventive purposes, experienced farmers recommend: adults should not be kept in the same room together with young animals. It is this mixing that often provokes the death of a large number of birds. When a disease of birds is observed, therapy starts with quarantine measures: sick individuals are necessarily isolated from the rest. When severe symptoms are observed, treatment is impossible, the bird is destroyed, burned. This is necessary to prevent the development of an epidemic.

Experts say: it is imperative to treat the chicken coop with special disinfectants. This method is optimal for reducing the likelihood of infection, infection from the outside. When there are sick individuals, such measures are taken immediately, on an emergency basis, since it is necessary to prevent the death of the livestock.

Processing is carried out on an ongoing basis, regularly, even if there is no cause for concern yet. It is advisable to carry out it at least once a month. Good care and proper balanced nutrition are of great importance. A healthy bird has a more stable immunity.

Disinfection of the chicken coop is also used as a preventive measure, with a certain frequency. Disinfection helps keep chickens free from disease and maintain sanitation. How to properly disinfect a chicken coop, you will find out in our article.

Infectious diseases

Infections develop as a result of infection of the chicken with all kinds of viruses. They are carried directly by birds, they can be brought in from the outside. Undoubtedly, the most dangerous factor is the transmission of the virus to healthy individuals from sick individuals. If the livestock is covered by an epidemic, you can lose the entire bird.

Another negative factor: a number of ailments are transmitted virally not only to chickens, but also to other species of poultry, animals, and some pose a real threat to humans. In case of untimely treatment, the liver, other organs and systems of vital activity are under attack in the first place. There is often a high probability of death of the bird. Let's consider specific diseases of chickens.

Pullorosis typhoid

This ailment is widespread and has a bacterial nature. It poses a serious danger not only to birds, but also to humans. Young animals less than two weeks of age are usually infected.

The symptoms are as follows.

1. Chicks are lethargic, passive.
2. Young growth huddles in heaps, squeezes paws.
3. A plaintive squeaking is constantly heard.
4. The eyes are usually closed, as the light of the sick is irritating.
5. The wings are down.
6. Feces are in the form of a thin, viscous, frothy porridge with a yellowish tinge.
7. An increase in temperature is observed.
8. Breathing is disturbed.
9. The scallop may turn blue.

Ultimately, about 70 percent of the young may die. Chicks die in convulsions.

It is necessary to isolate all patients immediately. Drug therapy is effectively carried out with furazolidone, biomycin.

Colibacillosis

Distributed among chickens and other poultry. In this infection, Escherichia coli becomes the causative agent. Adult birds can get sick in a chronic form, but in young animals the disease is acute. The signs are as follows:

• squatting on the paws;
• weakness;
• decreased appetite;
• thirst;
• apathy;
• trouble breathing;
• severe indigestion.

Already visually, you can determine the ailment. It is extremely important to carry out treatment in a timely manner, since there is a real threat to human health. Most often, therapy is carried out with terramycin, biomycin. The demand for ampicillin, sarafloxalin, enrofloxacin is also growing.

Pasteurellosis

Here, individuals whose age has not yet reached three months are under attack. Birds and rodents who have recovered suffer from the disease. The disease can be chronic, or acute form... Let's designate the external characteristics.

1. Malfunctions of the liver, other internal organs and systems.
2. Accumulation of mucus in the nose.
3. A sharp decrease in appetite.
4. Wheezing, respiratory failure.
5. Thirst.
6. The scallop may turn bluish in color.

Important! Pasteurella can survive for a long time in water with food, in manure, in corpses. When infection with this virus is detected, the bird is necessarily burned after slaughter. The coop is thoroughly disinfected.

The optimal solution is the prevention of the disease. The bird is vaccinated with cholera serum. If an ailment is detected, there is a chance to save the young: for this, therapy with antibiotics is carried out. However, the efficiency is low. Norsulfazole, tetracycline are used.

Salmonellosis

The most dangerous ailment that poses a great threat to both birds and humans. Infection occurs through feed and droppings, eggs, through contact with poultry. In addition, infection is likely even by airborne droplets.

Symptoms:

• swelling of the joints on the legs;
• weakness;
• eyes watery, fester;
• intense thirst;
• appetite decreases sharply;
• breathing is difficult;
• the stool is frothy;
• growth retardation is observed;
• the peritoneum becomes inflamed.

Death agony is observed with convulsions, twitching of the head.

First of all, in the acute course of the disease, the liver and gastrointestinal tract are affected. Therapy is most often prescribed with furazolidone. It lasts 20 days; streptomycin must also be taken for 10 days. When a week has passed, the course is repeated. Chlotetracycline and sulfanilamide should be added to the feed for 10 days. Complete thorough disinfection is carried out. All birds that remain infected should be supported by taking chloramphenicol: it is given three times a day, for a whole week.

Chicken pox

1. Breathing becomes heavy.
2. The bird weakens, almost does not move.
3. Swallowing is also hard.
4. Red spots appear on the skin.
5. Yellow pockmarks are spread everywhere: along the earrings, the crest, in the eye area. Gradually they turn brown and darken.

Drug therapy can be carried out effectively only at the very first stage of the development of the infection. You will need boric acid, furacilin, or glycerin, galazolin. All affected areas are thoroughly wiped with these means. Antibiotics are relevant: biomycin, tetracycline. They are taken throughout the week. Rinse the throat with a decoction of chamomile. 5% chloramine is useful for treating internal growths. All this is permissible to apply if a decision is made to try to save the bird. However, experts note: the best solution is to slaughter diseased individuals in order to prevent the spread of infection, the emergence of an epidemic.

To reduce the risk of an illness, it is worth carefully observing hygiene standards, as well as regularly cleaning the house and disinfecting it.

Newcastle disease

The virus is transmitted quickly, in different ways: through food and water, droppings. Individuals easily infect each other. Almost all organs are affected, from the liver to the nervous system. The clinical picture is as follows.

1. Birds make croaking sounds.
2. Reflexion of swallowing is impaired.
3. Appetite decreases sharply.
4. Mucus accumulates in large quantities in the mouth, nasal cavity.
5. Chickens are lethargic, passive.
6. Coordination is impaired, there is a movement of individuals in a circle, disruptions in orientation in space.
7. The scallop gradually takes on a blue tint.

All livestock have to be cut. The bird is burned or covered with lime. When the disease is acute, it can be transmitted to humans.

The only effective measure is timely prevention and hygiene.

Helminthosis helps flubenvet. It only needs three grams per kilogram of feed. It is important to carry out therapy in the course of a week.

When the upset stomach continues after treatment, you should seek advice from your veterinarian.

A distinctive feature of such ailments is that only the directly sick bird is at risk. The epidemic does not threaten healthy individuals. In this case, treatment is necessary to preserve the livestock.

Chickens often experience disruptions in the functioning of the gastrointestinal tract. This is typical in case of improper nutrition, when the feed contains clay or sand. It is bad if the amount of protein consumed is not balanced. Avitaminosis occurs. When diseases are already in progress, the clinical picture becomes confusing as symptoms overlap. In case of untimely therapy, the bird dies.

A clean chicken coop is an important part of bird health

The zoological regime in the chicken coop plays an important role. He must be carefully monitored. Risk factors:

• inactivity of the bird;
• poor ventilation system;
• wrong temperature conditions, hypothermia;
• excessive illumination.

Mechanical injury is dangerous. This happens when other animals attack, falls, pinches of foreign objects in the stomach. Sometimes chickens suffer from poisoning by pecking on poisonous plants. In the hen house, the zone of residence of individuals, walking, everything should be strictly controlled.

Dyspepsia

The whole problem is in the wrong diet. It provokes dyspepsia or indigestion. This is extremely dangerous for young animals that have not yet crossed the threshold of 3 weeks. Inexperienced farmers start training poultry to coarse feed too early. In addition, it is important to monitor the freshness and purity of the water. Dyspepsia is chronic, due to toxic poisoning, and also acute - the intestines, the stomach itself, become inflamed.

Clinical picture:

• lack of appetite;
• liquid feces with undigested fragmented food residues;
• temperature increase;
• apathy;
• convulsions of the paws;
• hardening of the abdomen.

Therapy is based primarily on the translation into a correct, well-balanced diet. Chickens are kept on a special diet: all feed must be easy to digest. Instead of water, they give a soda solution, potassium permanganate. If food poisoning is detected, sulfonamides and antibiotics will be needed.

It is extremely important not to allow the development of the disease. Drinking bowls with feeders must be kept clean at all times. Particular attention should be paid to nutrition.

Goiter atony

A fairly common ailment provoked by an untimely, poorly balanced diet. As a result, feed begins to accumulate in the goiter, which leads to its obstruction. Visually and tactilely, you can determine the ailment by sagging, hardening of the goiter. The goiter can block the airways as well as the jugular vein. In this case, the individual will die.

If this does not happen, you can try to cope with atony. A gentle light massage is done. Using a probe, a little vegetable oil is instilled into the goiter. Then the goiter is massaged again, the chicken is turned upside down. It is important to remove the contents of the goiter. After the procedure, it is advisable to pour potassium permanganate into the throat.

Gastroenteritis

The disease is usually called intestinal flu. If the bird is fed irregularly, the food is of insufficient quality, and gastroenteritis develops. Sometimes stomach defects such as polyps are the cause. Stressful situations are dangerous, as well as allergic reactions to specific types of feed.

Symptoms will allow you to determine the development of intestinal flu:

• temperature rise;
• apathy;
• stomach upset;
• chickens have no appetite;
• stool is watery, frothy, with a pungent odor;
• the scallop turns blue.

One of the signs of gastroenteritis is a blue crest

Treatment is associated with improved nutrition, diets. The diet should be half-starved, all vitamins and minerals are needed easily digestible. Laxatives and antibiotics are used. It is advisable to prevent the development of the disease: you need high-quality food, it is important to observe hygiene.

Salpingitis

This is an inflammation of the oviduct that occurs with biliary peritonitis. The disease is provoked by poor feeding, lack of vitamins. As a result, eggs are laid too early, leaving them soft and without shells.

It is important to make the diet balanced, to increase the content of proteins and vitamins. If there is inflammation, but the oviduct has not yet fallen out, there is a chance to cure the bird. But you will need regular check-ups with a veterinarian.

Bronchopneumonia

With hypothermia, an inflammatory process begins in the respiratory organs. Sometimes young animals get caught in the rain, a sharp temperature drop is harmful. Sometimes pneumonia is a complication of an infectious disease. The bird becomes lethargic, breathing is hoarse, there is no appetite, mucus is secreted from the nose and throat.

Measures are taken immediately, otherwise the young will die in a matter of days. Used to treat penicillin, terramycin. Sick individuals are resettled, everything is thoroughly disinfected.

Cloacite

Poor living conditions, lack of vitamins, fluoride and calcium provoke the development of cloacite. Chickens suffer from hemorrhagic ulcers, mucosal inflammation, indigestion. Individuals lose weight, stop laying eggs.

Treatment can be carried out by washing the mucous membranes with rivanol, treating them with petroleum jelly and anesthesin. For prophylaxis, vitamin flour is needed in the diet, as well as alfalfa, ground vegetables.

Diseases caused by insects

It is extremely important to always monitor the condition, behavior of chickens, and also regularly examine them. The bird also suffers from insects: this is manifested in anxiety, scratching. You can see small holes on the surface of the skin if you spread the plumage. Fleas, ticks with chewing lice provoke diseases.

Fleas settle in the litter, so they can be dealt with if you process the entire room, change the litter, and carry out deratization.

Puff lice are small, but very dangerous. Aerosols Insektol, Arpalit help. Feathers are treated with sprays, but the product should not get into the eyes or on the beak. The chicken coop and all equipment are disinfected.

Molds also cause ailments. Among them, aspergillosis is the most widespread. Infection is likely if the feed is moldy, and the conditions of detention do not meet sanitary standards. The defeat goes to the respiratory tract and internal organs.

Aspergillosis affects the lungs of birds

The bird becomes lethargic, breathing becomes disordered, quickens. Sometimes the eyes become inflamed, sneezing and coughing are observed. Individuals are emaciated, suffering from indigestion. Within a few days, patients may die from the developed paralysis.

The therapy is carried out using iodine inhalations. Nystatin helps: it is given to drink. Chickens need 5 mg, and adults - 20 mg.

Be extremely careful. Monitor the condition of the bird, feeding and housing conditions.

Video - Diseases of chickens and their treatment

Bird pox (VARIOLA)

Smallpox (smallpox - diphtheria, pips, pseudo-membranous tonsillitis, malignant catarrh, yellow scurvy, cutaneous tubercle, contagious epithelioma, diphtheria, etc.) of birds is a contagious disease characterized by the formation of specific smallpoxes on the skin and diphtheroid lesions of the mucous membranes of the respiratory tract and the conjunctiva.

History reference. Guzard was one of the first to describe smallpox in chickens (Huzard, 1778). Bollinger (Bollinger, 1873) discovered specific inclusions in the cells of tissues of birds with smallpox. Later, it was found that these inclusions are clusters of tens of thousands of virions, and they called them "Bollinger bodies". Before the discovery of the causative agent of smallpox, skin (smallpox) and diphtheroid (diphtheria) forms of its manifestation were defined as two independent diseases. Only after 1902, when the Russian scientist F.P. Polovinkin and the German researchers E. Marx and A. Sticker (E. Marx and A. Sticker) established that the causative agent of smallpox in birds is a virus. T. Garnwath (T. Garnwath, 1907) and others proved that pathological material taken with smallpox can cause disease in birds, characterized by damage to the mucous membranes, and the material of the latter - a smallpox rash on the skin. E. Marks and A. Sticker, and then Juliusberg (Julmsberg, 1904) and others noted the difficulty of filtering the virus as a result of firm fixation on the filter. It was possible to filter the virus only through the Berkefeld V filter, and Findlay (1928) through the Chamberlain filter L. N. V. Likhachev and S. S. Kasatkevich (1935) established the possibility of virus purification by diffusion through a column of 10% gelatin.

A. Borrel (A. Borrel, 1904). discovered in the skin of a bird sick with smallpox special little bodies, called at the beginning strongyloplasmas, and then elementary particles or Borrell's little bodies (virions). This discovery was confirmed by other researchers, and it acquired great importance in the diagnosis of smallpox. But, despite the widespread prevalence of smallpox in the countries of the world among birds of many species, there is still no consensus on the difference in the causative agents of smallpox for birds of different orders. It is firmly established that the chickenpox virus and the smallpox virus of pigeons exist independently, and Kikut and Gollub (W. Kikuth and N. Gollub, 1932) also identified the canarypox virus. In 1933 this was confirmed by Burnet, Herzberg and others.

Etiology. Smallpox affects birds of the suborder chicken, the order of pigeons and the order of passerines, the causative agents of which are chickenpox virus (Virus borreliota gallinorum), pigeon pox virus (V. b. Columborum) and canarypox virus (V. b. Fringillorum), respectively. Some researchers (Van Rooyen, 1954; A. Maug, 1960, and others) are trying, due to some peculiarities, to single out the turkeypox virus into a special group. All these viruses belong to the group of large epitheliotropic poxviruses, combined on the basis of biological properties characteristic of all pathogens of smallpox. However, in terms of pathogenic and immunogenic properties, they differ from each other, which allows them to be distinguished into the indicated varieties. Individual strains of the listed viruses can be monopathogenic in relation to birds of the indicated suborder and orders, as well as bipathogenic (this is characteristic of strains of the pigeon pox virus in relation to birds of their order and suborder - actually chicken) and trypathogenic, which is typical for many strains of canarypox virus, although intense immunity from them and is created, as a rule, only against the canarypox virus. Smallpox viruses of pigeons and chickens of bipathogenic strains create mutual cross immunity in most birds of the corresponding order and suborder, but usually less intense in birds not of their own order or suborder (Table 1).

Table I Immunobiological properties of avian pox viruses

Virus	Pathogenicity of strains	Reaction			Immunity
		In chickens	pigeons	canaries	In chickens	pigeons	canaries
Smallpox chickens Smallpox pigeons smallpox canaries	Monopathogenic Bipathogenic Bipathogenic Tripathogenic	+ + + + + + + +	—	—	+++ ++	—	—

Legend: - there is no visible follicular reaction, does not cause the formation of immunity; + follicular reaction is poorly expressed, the formation of weakly expressed immunity; ++ follicular reaction is well expressed, the formation of moderately pronounced immunity; -f -J- + - the dollicular reaction is strongly pronounced, the formation of a tense and long-term immunity.

The smallpox virus, isolated from turkeys, is similar in its properties to the bipathogenic strains of the chickenpox virus.

Some microorganisms, more often from the group of cocci, Bact, contribute to the onset of the disease and aggravate its course (especially of the diphtheroid form). necrophorus, etc.

The sizes of fowlpox viruses vary in the range of 180-350 mm; in smears processed by the method of silvering, virusoscopy through the immersion system of a light microscope, their value is usually about 250 mmk. Wittmann (1958) discovered a precipitating antigen in the virus. From it, specific precipitating antibodies are formed in the body, which can be detected in blood serum by the reaction of diffusion precipitation (RDP) in an agar gel.

Virus resistance. The virus, released (purified) from the tissue, is not resistant to physical factors and chemical agents, and located in tissue cells (which is more often in natural conditions) remains viable for a relatively long time. Smallpox viruses survive for a long time when dried and frozen. This characteristic of their property is an important factor contributing to the long-term preservation of viruses in natural conditions. High temperatures, acids, sun rays and putrefactive microorganisms have a detrimental effect on viruses, accelerating the decay of tissues and the destruction of virus-containing cells. In tissues, when heated to 100 °, the virus dies in 5 minutes, up to 80 ° - in 30 minutes, up to 60 ° - in 3 hours; at a temperature of 37-38 ° and good aeration, the virus persists for eight days; in water at 56 °, the virus dies in 30 minutes. In a finely ground tissue suspension at a temperature of 0 °, the virus remains viable for three months, and when stored in a mixture of phosphate-buffered saline with glycerol (at pH 6.8) - 20 months, at 7 ° - eight months, and at 30 ° - three months. At temperatures below -15 ° in the dry epithelium, the virus remains viable for 15 years. In dry epithelium at a temperature of 0-6 ° the virus persists for eight years, at 18-22 ° for six months, and a virus dried in a vacuum under the same conditions - up to two years or more.

In an acidic environment (pH 3), the virus dies in an hour. In 5 minutes, the virus is inactivated by 1% solutions of acetic acid, mercuric chloride and caustic potassium. Ethyl alcohol (70-95 °) inactivates the virus in 10 minutes, and 50 ° at 20-26 ° in 30 minutes; A 3% phenol solution, when exposed to a virus in a dry epithelium at 20 ° C, inactivates it in 30 minutes, and 1-2% solutions in 90 minutes. Formalin solution 1: 500 inactivates the virus in dry epithelium in 8 hours.

A.A. Rahimov (1962) found that in contaminated outdoor areas in Azerbaijan in summer and autumn, the chickenpox virus remains active at a temperature of 20-29 ° C and a relative humidity of 26-48% for 143 days, and indoors at 19 -25 ° and relative humidity within 24-36% -158 days. In summer, the virus dies in 6 hours from sunlight in areas not contaminated with droppings, and in areas polluted at 24-33 ° and a relative humidity of about 26%, it is inactivated after 11 hours. On the surface of down and feathers outside the house at a temperature of 3-30 ° and a relative humidity of 28-48%, the virus remains virulent for 195 days, and on the surface of the eggshell at 5-24 ° and a relative humidity of 28-60%, no less 60 days. In non-chlorinated tap water, the virus remains virulent for 66 days, and in river water at 18-21 ° - 76 days.

Epizootological data. Smallpox poultry can get sick in all seasons of the year, but more often get sick and more difficult to transfer the infection during the "molt" period, in autumn and winter, depending on climatic conditions and maintenance. Young animals and decorative birds are especially susceptible to smallpox. In an adult bird, mainly in pigeons, a skin form is more often noted, and in young animals a diphtheroid or mixed one. This is due to the fact that in an adult bird the virus mainly enters the body through damaged skin, and in young animals through the mucous membrane of the oral cavity. In the warm season, as well as in countries with a hot climate, smallpox is more often recorded in birds, and in winter and in countries with a cold climate, mucous membranes are affected in birds. The frequent illness of birds in early spring can be explained by vitamin deficiency and a violation of mineral metabolism, which lowers the body's resistance and increases the possibility of virus penetration into the body even through the intact mucous membrane of the initial part of the digestive tract (especially with vitamin A deficiency).

Piglets may be susceptible to certain virulent strains of chickenpox virus. Man does not get sick with smallpox.

The main source of the smallpox virus is sick birds and virus carriers, which disperse it into the external environment with falling off epithelium, crusts, films, feces and discharge from the nasal and oral cavities and from the eyes. The carriers of the virus can be both domestic and wild birds, as well as rodents and blood-sucking insects. So, in the body of the Persian tick, which was pumped by the blood of chickenpox patients, the virus lasts 30 days, in the body of a bug - 35 days, ornithodorus tick - 97 days, in flies - 20 days, and in mosquitoes and mosquitoes - 210 days.

Infection occurs when a healthy bird comes into contact with a sick bird and a virus-carrying bird, as well as through virus-contaminated eggs, feed, water, equipment and clothing of service personnel. The virus can also spread by aerogenic means.

Smallpox outbreaks are usually enzootic, but epizootics are sometimes noted. Poultry sickness on the farm usually lasts about 6 weeks.

In a sick bird, egg production decreases 5 times or more and slowly recovers after recovery; the hatchability of chickens decreases not only during illness, but also for a considerable time after the chickens have been ill. Often, only about 20-25% of the chicks are hatched. A bird that has had smallpox loses its natural resistance for a long time and, as a result, becomes more sensitive to other diseases.

The pathogenesis is determined by the pronounced epitheliotropy of smallpox viruses. Once in the epidermis or in the epithelial layer of the mucous membrane, the virus multiplies, forming smallpox foci, the severity of which depends on the resistance and reactivity of the organism and on the virulent properties of the strain.

From the primary smallpox foci, the virus enters the bloodstream and internal organs within a day. I.G. Grinets, Yu.F. Borisovich and L. S. Ageeva (GNKI, 1963) found that virulent strains of chickenpox virus, entering the blood and hematopoietic organs of a susceptible organism, strongly affect the cells of the peripheral blood and reticuloendothelial system, affecting bone marrow cells up to the formation of necrosis, which causes significant dysfunctions of the blood and hematopoietic organs. The virus, which has multiplied in blood cells and the endothelium of blood vessels, is transferred to other, mainly unaffected areas of the skin and mucous membrane, where new foci of smallpox appear. Within 24-48 hours after skin infection of a bird, the virus can be detected in the spleen, lungs, liver, gall bladder, heart and kidneys, where it causes dystrophy of parenchymal cells and changes in vascular endothelial cells.

Usually, the smallpox process has a pronounced generalized character with the greatest damage to the epidermis of the skin, epithelium of the mucous membranes and internal organs, changes in which are characterized mainly by hyperplasia of epidermal cells with the appearance of Bollinger bodies in their plasma. In chickens, simultaneously with the smallpox process developing in the skin, there is an intensive infiltration of the subcutaneous tissue with lymphoid and pseudo-eosinophilic cells. The diphtheroid process begins more often on the mucous membrane of the oral cavity, from where it spreads to the mucous membrane of the nose, larynx and other parts of the body. It can start on its own without skin lesions, but is more often secondary to the generalization of smallpox. The most dangerous are secondary lesions of the mucous membrane of the larynx, since due to the formation of diphtheroid films in the bird, breathing and swallowing food becomes difficult, which leads to exhaustion and weakening of the body, and sometimes causes blockage of the larynx and death of the bird from suffocation.

Pathological changes in diphtheroid and mixed forms of smallpox are the result of the combined action of the virus and secondary microflora. The influence of the latter is often noticeable even when the smallpox process has ended and there is no longer a virus in the affected areas. In this case, the remaining signs of "diphtheria" (in the absence of the virus) often lead to diagnostic errors. If the smallpox process is not greatly complicated by the secondary microflora, the diphtheroid films are rejected and the mucous membrane regenerates, and in the case of pronounced complications, deep cicatricial ulcers do not heal for a long time. Usually, the smallpox process in chickens ends in 17-45 days after the onset of the disease.

Symptoms of the disease. The incubation period depends on the virulent properties of the virus, the ways of its penetration into the body, as well as on the age and physiological state of the bird and lasts 4-8, less often 10-15 days. The disease usually proceeds subacutely, but often takes a chronic and less often acute course. Distinguish between cutaneous (the most typical form), diphtheroid and mixed forms of smallpox. The latter happens most often, but one of the forms necessarily predominates. Sometimes the so-called latent forms of smallpox are observed with damage mainly to the internal organs. This form is more often observed in birds with reduced resistance and reactivity of the organism, as well as in birds of the order of passerines, in particular in canaries. Some researchers are trying to isolate from the initial stage of the diphtheroid form of smallpox into a separate form, the so-called catarrhal form according to one clinical sign not quite characteristic of smallpox, more often observed with mixed infection or abortive course of the diphtheroid form of smallpox.

Rice. 1. Smallpox lesions on the head of a rooster (according to VN Syurin, 1965).

With cutaneous and mixed forms of smallpox, usually on the 4-5th day after infection in chickens on the skin at the base of the beak, eyelids, on the crest, beards and other parts of the body, round, first pale yellow, and then reddish spots appear, gradually turning into warty epitheliomas (growths), often merging with each other and sometimes reaching 0.5 cm. After a few days, their surface becomes rough, dark brown in color (Fig. 1).

Pockmarks are formed 7-9, sometimes 14 days. At their base, inflammation develops and hemorrhages appear. The pockmarks are covered with crusts, which, in the absence of complications, disappear within 7-10 days without leaving noticeable scars. If the scab is removed, then under it is noticeable accumulation of serous-purulent exudate, covering the granulating surface. After a rash of primary pockmarks, on the 17-19th day after infection in chickens, sometimes the phenomenon of a secondary smallpox process is observed on previously unaffected areas of the skin, more often in featherless areas of the head, legs, wings and near the cloaca. Sometimes smallpox in chickens is accompanied by the development of keratitis, and with complications by secondary microflora, panophthalmia.

The general condition of the bird is depressed, feathers are ruffled, appetite is reduced or completely absent.

With diphtheroid and mixed forms on the mucous membranes of the oral cavity, tongue, nose, larynx, trachea, bronchi, accessory cavities, sometimes under the cuticle of the stomach and on the intestinal mucosa, a rash appears in the form of whitish, opaque, several raised nodules. They quickly spread and, increasing in size, often merge with each other, become yellowish and contain a curdled consistency of necrotic tissue in the form of films connected to the submucosa. If these diphtheroid pseudomembranes are removed, bleeding erosions are formed, and when they are contaminated with microbes, a purulent process develops. Diphtheroid films make breathing difficult, so birds have an open mouth and make whistling or wheezing sounds when they breathe.

In pigeons, the cutaneous form of smallpox usually predominates with the localization of smallpox lesions along the edges of the eyes, at the base of the beak and on the legs. Erosions and ulcers are sometimes visible on the oral mucosa. Sometimes iritis and cataracts are noted.

A favorable outcome of the disease can only be in those birds that were healthy and well developed before the disease, were kept in exemplary sanitary and zoohygienic conditions and in which the cutaneous form of smallpox is not complicated, and smallpox lesions are localized only on the head. Usually, however, the prognosis is unfavorable, since it is unprofitable to keep sick birds.

The percentage of bird deaths largely depends on the age and conditions of keeping. In some poultry houses, 10 to 70% of birds die. A particularly high mortality occurs among young animals with diphtheroid and mixed forms, complicated by secondary microflora. Among pigeons, mortality ranges from 8%, but sometimes under poor conditions it rises to 25-30% among adult birds and up to 100% among young birds.

Pathological changes are determined by the form and duration of the course of the disease and correspond to its clinical symptoms. In cutaneous and mixed forms, smallpox lesions are more often localized on the skin and mucous membranes of the oral cavity and upper respiratory tract, larynx and trachea, as well as bronchi, sometimes on the mucous membrane of the pharynx, esophagus and intestines (duodenum, blind and rectum). In the diphtheroid form, the mucous membrane of the trachea, bronchi and accessory cavities is affected much more often. Sometimes smallpox lesions are found under the cuticle of the stomach, on the mucous membrane of the esophagus and intestines. If the mucous membrane of the air sacs is involved in the process, it becomes cloudy, a mucopurulent exudate appears in the nasal cavity, and if the infraorbital sinus is affected, then it, like the trachea, is filled with a yellowish-brown curdled-crumbly mass. As a rule, the conjunctiva and eyes are affected. In some birds, skin lesions are weak, but changes in the internal organs are significant and are characterized by small yellowish foci in the liver, pulmonary edema, punctate hemorrhages on the epicardium and serous membranes. The intestinal mucosa is stained and loosened, and sometimes it is riddled with small hemorrhages. In the chronic course of smallpox, the liver, kidneys and heart muscles are degenerated, the spleen is slightly enlarged, swollen. The bodies of the fallen birds are emaciated. In cases where there is no smallpox rash, exhaustion and degeneration of individual organs and muscles are the only pathological changes that characterize such a course of smallpox.

On histological examination, smallpox lesions are characterized by hyperplasia of epithelial cells and hydropic dystrophy with moderate hyperkeratosis, as well as thickening of the epidermal layer due to increased multiplication of its cells. In the subcutaneous tissue, there is an expansion of blood vessels, lymphoid-pseudosinophilia and a histiocytic cell reaction. With a primary lesion of the mucous membrane, signs of smallpox epithelioma are found, and later the phenomenon of diphtheroid inflammation.

In the plasma of epithelial cells affected by the virus, Bollinger bodies are found, the finding of which confirms the etiology of the disease. With an increase in the size of inclusions, the destruction of the nucleus and cell death occurs. On the basis of histological examination, smallpox is differentiated from A-avitaminosis: with smallpox, the pathological process is localized mainly in the squamous stratified epithelium.

The diagnosis is made on the basis of the analysis of clinical and epizootic data, pathological and histological changes and laboratory studies (viroscopy, RDP, bioassays with the isolation and identification of the virus, if necessary, on developing chicken embryos, tissue cultures, chickens and pigeons, using neutralization and hemagglutination reactions, luminescent microscopy, etc.).

Given the relevant epizootic data and the scalp lesions characteristic of smallpox, it is not difficult to diagnose smallpox. If lesions are found only in the oral and nasal cavities or in internal organs, it is necessary to carefully examine all birds to identify at least a few with characteristic signs of the disease and make smears to detect smallpox virions in them. In doubtful cases, it is necessary to put a bioassay and make smears from fresh pockmarks that have not yet been complicated by secondary microflora.

Rice. 2. Smallpox folliculitis on the right shin of a chicken on the 8th day after rubbing the pigeon pox virus into feather follicles - a positive reaction to a dry embryo vaccine (according to Yu. F. Borisovich, 1968).

Rice. 3. The button part of the chorioallantoic membrane of the chicken embryo, affected by the smallpox virus. Individual pockmarks are clearly visible (according to Yu. F. Borisovich and K. M. Islentyeva, 1967).

For the production of bioassays, they infect healthy chickens that have not been previously immunized against smallpox and have not had smallpox. The suspension is rubbed with a sterile brush into the slightly scarified surface of the ridge and into the follicles of the lower leg immediately after plucking out the feathers. If the test material contains chickenpox virus, then on the 5-7th day after infection, characteristic pockmarks appear on the ridge, and folliculitis, typical for smallpox, appears on the lower leg.

By examining smears from the material of fresh smallpox lesions (after processing them by the method of silvering), virions can be detected. The presence of many characteristic virions in smears ("scattering" type) confirms smallpox; their absence does not give grounds for excluding this disease.

The smallpox virus in epitheliomas can also be detected electronically by the method of adsorption of the virus from the test material onto the collodion film. With chickenpox, both immature bubble-shaped "viral particles" ranging in size from 60 to 200 mmq, and typical brick-like and oval mature virions are simultaneously detected. With negative contrasting of virions, filamentous structures are visible.

When setting up a bioassay, it should be remembered that a vaccine strain of pigeon pox virus can be isolated from a bird previously immunized against smallpox with a live pigeon virus vaccine, which causes a similar, but more benign inflammation of feather follicles in chickens without the formation of necrotic crusts (Fig. 2) and diphtheroid lesions of the mucous membranes. In this case, you need to isolate the virus in its purest form and identify it. For this, developing chick embryos are infected by applying material to the chorioallantois (Fig. 3), day-old chicks by injecting material under the skin in the area of ​​the inner side of the wing (after the introduction of the pigeon pox virus, the reaction is negative), and pigeons, rubbing the suspension into freshly nude feather follicles of the breast area muscles, etc.

Sometimes the diagnosis can be confirmed by RDP according to the method of Giordani and Chubb (1962), somewhat modified by G.A. Lezhava (GNKI, 1964). When setting this reaction, it should be borne in mind that precipitating antibodies in chickenpox appear in the blood serum usually between 11 and 36 days after the onset of the disease, mainly in older birds. The blood serum of a bird infected with a highly virulent strain of the virus gives a more pronounced RDP. But we must also remember that the precipitating serum of convalescents is often weakly active, and in 15% of chickenpox patients it is not at all possible to establish the presence of precipitating antibodies. Therefore, it is better to set the RDP with a knowingly active hyperimmune anti-smallpox serum obtained from males and the studied pathological material in the form of an antigenic suspension with a number of necessary controls. A positive reaction of precipitation (macro- or microvariants) confirms the diagnosis of smallpox, and a negative one still does not give the right to exclude smallpox ethnology of the disease.

Differential diagnosis. With smallpox, vitamin A deficiency, infectious laryngotracheitis of chickens, infectious bronchitis of chickens, infectious rhinitis of chickens, trichomoniasis in pigeons, thrush in chickens and pigeons, aspergillosis, candidiasis, respiratory mycoplasma, cholera and some other infectious diseases that can sometimes be mistaken for an atypical form of smallpox or, more often, when they occur simultaneously with smallpox.

Avitaminosis A excludes a negative bioassay, as well as histological data, which show that, in contrast to smallpox lesions, avitaminosis mainly affects the cylindrical epithelium of the mucous glands of the oral cavity, throat, tongue, esophagus, goiter and trachea, instead of which keratinizing flat multilayered etithelium grows and the normal state of the mucous glands and ciliated epithelium is disrupted; uric acid appears in the kidneys, which is then deposited under the epicardium and under the liver capsule. In the affected cells with avitaminosis A, there are also no intraplasmic Bollinger bodies.

Infectious laryngotracheitis of chickens is excluded by a negative “cloacal” test in chickens susceptible to laryngotracheitis, a precipitation reaction and a neutralization reaction in chickens, developing chick embryos and tissue cultures of chick or duck embryos, as well as the absence of a follicular reaction in chickens in a bioassay.

Infectious bronchitis of chickens, which has just appeared in the poultry farm, is excluded, given the lower virulence and the absence of typical smallpox lesions on the skin and mucous membranes. The specificity of the virus is determined by cross-checking the immunity of diseased chickens. In addition, chickens, mainly of brooding age, get sick with bronchitis.

An infectious rhinitis is excluded by staging a bioassay, viroscopy of the affected areas and cross-checking of immunity in recovered birds, as well as the absence of Bollinger bodies in the pathological material.

Cholera (pasteurellosis) and other infectious diseases of viral and bacterial etiology are excluded by setting appropriate bioassays and conducting bacteriological and histological studies of pathological material from sick birds.

Thrush, scab, aspergillosis and candidiasis are excluded on the basis that microscopy of pathological material in smallpox does not contain spores and mycelium of the corresponding fungi (and vice versa).

Mycoplasmosis and trichomoniasis, in contrast to smallpox, are characterized by negative results of follicular bioassay on poultry susceptible to smallpox and a precipitation reaction with anti-smallpox hyperimmune serum.

Immunity is characterized by the appearance of virus-neutralizing and precipitating antibodies in the blood serum of birds (signs of the presence of humoral immunity) and the formation of tissue immunity. Immunobiological restructuring of the organism of an infected bird begins from the first day the pathogen of smallpox enters it, but fully immunity is formed only after 3-4 weeks.

An adult, recovered bird with good body reactivity is immune for three years. After a single vaccination of chickens with the pigeonpox virus, immunity is less intense and less prolonged. For example, in young animals it remains up to 3-5 months, and in an adult bird up to 6-8 months. Moreover, if to create immunity in chickens using the chickenpox virus it is enough to cause inflammation of 2-3 feather follicles, then to create immunity with the smallpox virus of pigeons it is necessary that the inflammatory reaction spreads to at least 15-20 follicles when a virus is applied to them. titer ID50 not less than 10 ~ 4-10 ~ 5. Thus, the duration and intensity of immunity in a vaccinated bird largely depends on the immunogenicity of the virus strain used, the age of the bird, its reactivity and methods of immunization. The method and scheme of immunization of birds in the USSR are regulated by the current instruction on the use of dry embryo-virus vaccine from a pigeon strain (1968).

Treatment. There are no effective specific remedies for the treatment of birds with smallpox. V.V. Vinogradov obtained a preventive and therapeutic effect from the use of anti-smallpox gamma globulin after its introduction to a bird in a dose of 0.3 ml under the skin. According to the legislation, it is recommended to kill a bird sick with smallpox and an emaciated bird. Only in some cases is a valuable bird with mild smallpox lesions isolated in a separate room and treated symptomatically. Intramuscular injections of epinephrine 1: 10,000 are recommended with the addition of potassium iodide at a concentration of 0.07% to drinking water or, even better, when given in a mixture with milk.

In treatment, iodine preparations are preferred. After softening smallpox lesions on the skin with ointments, oils or glycerin and removing peeled off crusts, it is recommended to lubricate the ulcerative surfaces with tincture of iodine (you can also use a 3-5% solution of potassium permanganate or burn these places with lapis, undiluted creolin, tar and other disinfectants). The mucous membrane, after removing the diphtheroid overlays from it, is daily lubricated with a mixture consisting of 10% tincture of iodine and 90% glycerin (some authors recommend using this mixture in equal proportions, as well as a 3% solution of hydrogen peroxide, 0.5-2% - solutions of chloramine or dichloramine). The nasal cavity and conjunctiva are irrigated with 2-3% boric acid solutions daily after removal of the accumulated mucous secretion and washing with warm water until the inflammatory process stops.

Birds in which smallpox is complicated by a secondary bacterial infection are prescribed antibiotics (penicillin, terramycin, tetracycline, oxytetracycline, etc.). Sick birds improve the conditions of keeping and feeding. They give soft food in crushed form, greens, mashed carrots, alfalfa flour and other vitamin supplements are introduced into the diet. The inclusion of antibiotics (erythromycin, etc.) in the diet, as well as furazolidone, helps to reduce the mortality of the bird and accelerate its recovery.

Prevention and control measures. The success of the fight depends on well-organized, taking into account the specifics and characteristics of the disease, preventive veterinary and sanitary measures, timely diagnosis and correctly taken measures for the fastest elimination of smallpox. All anti-smallpox measures in the USSR are regulated by the current instructions for the fight against smallpox of birds (1970) and the main provisions of the Veterinary Regulations of the USSR (1967).

In smallpox-free farms, it is necessary to strictly carry out veterinary and sanitary measures aimed at preventing the introduction of the pathogen of smallpox into it and increasing the resistance of the poultry organism. Especially carefully these measures should be carried out by persons working on the farm and having birds for personal use. All poultry brought into the farm must be quarantined for a period of 30 days. In quarantine, the bird is systematically monitored by a veterinarian. When a bird suspicious of smallpox appears, the entire bird is carefully clinically examined, and pathological, viraloscopic, and, if necessary, a biological study of material from this bird is carried out to clarify the diagnosis.

The economy (farm, branch or settlement), in which smallpox is established, is declared unfavorable and thorough disinfection is carried out in it. The import and export of poultry, poultry products, feed, etc. are strictly regulated. A sick, weak and emaciated bird is killed, and a clinically healthy bird is immunized in accordance with the current instructions. A bird that falls ill within 20 days after vaccination (from among the "incubators") is also killed. Immunize all clinically healthy birds and those belonging to individual owners in the area of ​​a dysfunctional or threatened smallpox farm.

The meat of the killed poultry is used after a veterinary and sanitary examination in accordance with the rules of veterinary sanitary examination. Carcasses of emaciated poultry, as well as those with lesions in different areas, are disposed of. If smallpox lesions are found only on the scalp, it is disposed of, and the carcass and unaffected organs are disinfected by boiling. Corpses, blood and all post-mortem waste are disposed of. Down and feathers are disinfected and taken to processing plants in containers with double packaging and a special label "To be disinfected!" with an indication in the veterinary certificate of the trouble of the farm for smallpox. Down and feathers are disinfected with flowing steam, formaldehyde vapor, or by immersing them for 1 hour in an alkaline formaldehyde solution (A.A.Zakomyrdin, 1966).

It is forbidden to take out birds of all ages and species from the farm, with the exception of birds intended for slaughter at poultry processing enterprises, with strict observance of the necessary precautions. Eggs from safe poultry houses can be used for incubation only within the same farm. Day-old chicks, turkey poults and chicks of other species of birds should be removed from the incubation workshop, provided they are reliably isolated from poultry farms that are unfavorable for smallpox and other measures are taken to prevent the spread of smallpox infection. Selling chickens to the public is prohibited. Containers used to transport carcasses and eggs are disinfected after each use. It is recommended to disinfect soft containers (sackcloth, tarpaulin, matting, ropes, etc.) with flowing steam, but you can also disinfect it by soaking in disinfectant solutions or boiling in water with the addition of 1-2% soda, as well as process it in chambers using steam-air or steam-formalin methods. It is better to disinfect solid containers (cages, boxes, cushioning material, etc.) by immersion for 0.5-2 hours in baths with disinfecting solutions. It is prohibited to take out feed, droppings, equipment and inventory.

On a farm that is not doing well for smallpox, mechanical cleaning, disinfection and pest control are regularly carried out. As disinfectants, use a 3% hot solution of sodium hydroxide (exposure 3 hours), a clarified solution of bleach containing 2% active chlorine (exposure 4 hours), 2% formaldehyde solution (3 hours), 20% suspension of freshly slaked lime by whitewashing twice with an interval of 1 hour. It is recommended to spend 1 liter of the preparation per 1 m2 of the surface to be disinfected. Sealed rooms are disinfected with aerosols of a concentrated formaldehyde solution or formalin-creolinic mixture in a ratio of 3: 1, spending 20 ml of the preparation per 1 m3 of the room (exposure for 1 day). The houses must be clean and dry. Crowded poultry should not be allowed. Manure and garbage are subject to mandatory biothermal disinfection in accordance with the rules of the current guidelines. The quarantine is removed from the farm no earlier than two months after the elimination of the disease and the final disinfection. In farms that were previously unfavorable for smallpox, depending on the epizootic situation, for several years after the elimination of the disease, for a preventive purpose, a total immunization of birds is carried out in accordance with the current instructions for the use of dry embryo-virus from pigeon virus against smallpox. Preventive vaccination of poultry is also carried out in farms threatened by smallpox, including all poultry owned by individual owners.

Smallpox is a common viral disease domestic birds (chickens, turkeys, pigeons and canaries) and over 60 wild bird species representing 20 families. It is a slowly spreading disease. It is characterized by the development of isolated nodular, proliferative skin lesions on non-feathered parts of the body ( cutaneous form) or lesions on the mucous membrane of the upper respiratory tract, mouth and esophagus ( diphtheria form).

With a mild cutaneous form of the disease, mortality in the flock is usually low. However, it can be high in generalized infections. This happens with diphtheria, in poor environmental conditions, or when the disease is complicated by other infections.

Avian smallpox has no public health relevance. It usually has no effect on mammals. Avian pox viruses infect birds of both sexes, all ages and breeds. The disease is common throughout the world

Smallpox transmission.

Smallpox virus infection spreads by mechanical transmission of the pathogen to wounds on the skin. When handling birds during vaccination, people can carry the virus on their hands and clothing, which can then enter the eyes of susceptible birds. Insects can also be mechanical carriers of the virus and cause ocular infection in birds.

Smallpox symptoms.

The cutaneous form of the disease is characterized by nodular lesions on the crest, earrings, eyelids, and other non-feathered areas of the body. In the diphtheria form, ulcers or yellowish diphtheria lesions are formed on the mucous membrane of the mouth, esophagus or trachea, combined with mild or severe respiratory symptoms.

Morbidity and mortality.

Smallpox incidence in chickens and turkeys, ranges from a few birds in a flock to an entire flock when exposed to a highly virulent virus and neglected controls. When birds are infected with the cutaneous form of the disease, they are more likely to recover than when infected with the diphtheria form involving the upper respiratory tract. The effect of smallpox on chickens usually results in wasting and poor weight gain. When laying hens become infected, the time to start laying eggs is delayed. The disease lasts approximately 3-4 weeks, but in the presence of complicating factors, the period can be much longer.

In commercial turkey breeding, stunting is more financially important than mortality... Most of the losses are attributed to blindness due to cutaneous ocular lesions and starvation. If smallpox infects brood flocks, egg production may decrease and impaired fertility... With an uncomplicated mild infection, the disease in a flock can last 2-3 weeks. Severe outbreaks often last 6, 7, or even 8 weeks.

Mortality in flocks of chickens and turkeys is usually low. However, in severe cases, it can be higher than 50%. The morbidity and mortality from smallpox among pigeons and parrots is about the same as in chickens. In canaries, smallpox can cause mortality rates of 80-100%. Significant mortality is also observed in quails when they are infected with the quail pox virus.

The first signs of smallpox observed in turkeys are small yellowish eruptions on the catkins and other parts of the head. They are soft and easily removed at the pustular stage. In their place, there are inflamed areas covered with sticky serous exudate. The corners of the mouth, eyes and bucco-pharyngeal membrane are usually affected. Further, the lesions enlarge and become covered with a dry scab or a yellowish-red or brown mass, similar to a wart.

In small turkey poults, the head and legs may be completely covered with lesions. The disease can even spread to the feathered parts of the body. In unusual outbreaks of smallpox in turkey flocks, proliferative lesions may occur in the oviduct, cloaca, and the skin around the anus.

Diagnosis

Signs typical of fowlpox must be confirmed by histopathology (presence of cytoplasmic inclusions) or by virus isolation. The diphtheria form of the disease in chickens associated with respiratory symptoms must be distinguished from infectious laryngotracheitis and infection caused by herpes virus... Lesions caused in small chickens deficiency of pantothenic acid or biotin or toxin T-2 can be mistaken for smallpox lesions.

Chickenpox vaccine

The chicken embryo vaccine contains live, unreduced smallpox virus, which can cause serious illness in chickens if used improperly. It is inserted into the wing web of four week old chicks and pullets approximately 1–2 months before the expected start of egg production. Chickens can also be vaccinated at one day of age. One vaccination provides lifelong protection.

Pigeon pox vaccine

The pigeon pox vaccine contains a live, unreduced virus naturally occurring in pigeons. This vaccine can cause severe reactions in these birds if misused. The virus is less pathogenic for chickens and turkeys. It can be inserted into the wing web and can be used for chickens of any age.

Turkeys can be vaccinated at any age in the wing membrane or drumstick. If necessary, you can vaccinate one-day-old turkey poults, but to establish better immunity, it is more correct to wait up to 8 weeks. Re-vaccination during growth is recommended. And it is imperative to re-vaccinate the turkeys left as producers.

Quail smallpox vaccine

For immunization of quails, chickens and turkeys, there is a live vaccine based on quail pox virus... But it does not provide adequate protection against chickenpox infection.

Vaccination results

After 7-10 days after vaccination, the flock should be examined for results. The result may be a swelling of the skin or crust at the vaccination site. This testimony successful vaccination... Immunity usually develops 10-14 days after vaccination. Most susceptible birds should have these results if the vaccine is used correctly. Most of at least 10% of birds should be examined for such evidence of vaccination.

The absence of signs of vaccination indicates that the bird has already been vaccinated or received a bad vaccine (expired or exposed to harmful effects) or it was administered incorrectly.

Vaccination is indicated under the following conditions

1) if the flock in the house was infected in the previous year; all young birds that are already in the poultry house or that have got there from other places should undergo compulsory vaccination against smallpox; 2) if there was smallpox last year and the pigeon pox vaccine was used for immunization, it is necessary to re-vaccinate the birds with the chickenpox vaccine; this is due to the short duration of the action of the immunity obtained when using the pigeon pox vaccine; 3) to protect against infection from nearby poultry houses in areas with a predominance of smallpox, it is necessary to apply the chickenpox vaccine.

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