Infectious tracheitis (ITT) is a viral disease that mainly affects chickens. The virus is localized in the mucous membranes of the larynx, trachea, and less commonly the conjunctiva of the eyes and nasal cavity. The disease was first described in 1925 in the USA, but there is reason to believe that ILT occurred earlier.

Currently, infectious chicken laryngotracheitis occurs in many countries: England, Holland, France, Germany, Hungary, Poland, Yugoslavia, Canada, USA, Italy, Sweden, Spain, South Australia, New Zealand, Indonesia.

In Russia, outbreaks of the disease are periodically recorded in all regions, but mainly large poultry farms suffer from ILT.

Characteristics of the disease

Chickens, peacocks, pheasants and some types of ornamental birds are susceptible to the disease. ILT most often manifests itself in young chickens aged from 60 to 100 days, in disadvantaged areas - from 20-30 days of age.

The virus can also infect humans. This happens to people who work with vaccine material for a long time or are forced to come into contact with highly aggressive strains (workers of biofactories and laboratories). A person cannot become infected with poultry products - meat, eggs, feathers.

In chickens, the disease is transmitted “beak to beak.” A bird that has recovered from the disease develops strong immunity, but remains a lifelong carrier of the virus and infects other chickens. The same applies to birds vaccinated with live ILT vaccines. When such individuals are introduced into an unvaccinated herd, outbreaks of the disease occur.

The ILT virus is not transmitted through eggs, but can remain on the shell. Eggs from sick chickens cannot be incubated, but can be eaten.

The virus is sensitive to disinfection, external environment its stability is low - it can persist for several weeks on care items, clothing service personnel, feeders and drinkers, in droppings.

Symptoms of the disease

More often, infectious laryngotracheitis appears in the autumn and spring, when temperature fluctuations weaken the respiratory tract of chickens and general immunity. Factors such as high humidity and dust in the air, poor ventilation, and unbalanced feeding contribute to infection.

The incubation period is short and amounts to 1-3 days. In acute cases, up to 80% of the population suddenly falls ill, and the mortality rate of chickens reaches 50-60%.

In subacute cases, the disease spreads throughout the flock within 7-10 days, affecting up to 60% of the birds, and up to 20% can die. Often ILT becomes chronic with a waste of 1-2%.

Symptoms of the disease are always associated with damage to the respiratory tract:

• wheezing, cough, wheezing;
• discharge from the eyes and nose;
• when the trachea is compressed with fingers, a cough occurs;
• When examining the larynx, redness, swelling, pinpoint hemorrhages, and accumulation of mucous or curdled masses in the lumen of the larynx are visible.

The chickens are depressed, eat poorly, and there is a bluish coloration of the comb and earrings. Usually the bird recovers from the disease within 14-18 days.

Symptoms of laryngotracheitis sometimes occur in the conjunctival form. The eyes become inflamed, foamy and or mucous discharge is visible, and the third eyelid creeps over the eyeball.

After recovery from the disease, the bird becomes blind due to damage to the cornea. This course of infection is observed in chickens aged 20-40 days and covers up to 50% of the population.

At the same time, symptoms of respiratory tract damage are present in a small number of chickens - a few percent.

When opening a dead bird characteristic feature are severe redness of the trachea, the mucous membrane is swollen, dark cherry color throughout, often the lumen of the trachea is clogged with a blood clot. The lungs and air sacs are affected to a small extent, unless the virus is accompanied by a bacterial infection - colibacillosis, mycoplasmosis, etc.

The diagnosis is made based on the isolation of the ILT virus from the pathological material. The disease must be differentiated from b. Newcastle, infectious bronchitis of chickens, respiratory mycoplasmosis, hemophilia, chronic pasteurellosis.

Treatment and prevention

It is useless to vaccinate during an ILT outbreak; introducing an additional dose of the virus will only worsen the situation. When using this method, it is taken into account that in the future it will be necessary to regularly vaccinate newly arriving livestock against ILT, since the virus will remain on the farm forever.

Treatment in itself is impractical; an economically justified way out of the situation would be to slaughter the entire herd, disinfection and import of new livestock. If this is not possible, then they resort to methods of partial recovery: clearly sick and emaciated birds are culled, the rest are treated.

Therapy

Treatment of laryngotracheitis is nonspecific. Chickens are provided with good feeding, heating and ventilation in the house. Next, medications are used.

• To suppress concomitant bacterial infections, broad-spectrum antibiotics are given: enrofloxacin, norfloxacin, ciprofloxacin, tetracyclines. Furazolidone powder can be mixed into the feed at the rate of 8 g per 10 kg of feed.
• The gentamicin solution is used as an aerosol by spraying from a sprayer.
• To disinfect the poultry house in the presence of birds, lactic acid or iodotriethylene glycol is sprayed using an aerosol generator.
• Disinfection can be done by sublimation of chlorine turpentine at the rate of 2 grams of bleach and 0.2 grams of turpentine per 1 cubic meter. room volume, exposure 15 minutes.
• Drink solutions of complex vitamins - “RexVital”, “Chiktonik”, “Aminivital”, “Nitamin” and the like.
• The drug “ASD-2” is added to the wet mash at a dose of 1 ml per 100 heads.

Measures to prevent infectious laryngotracheitis come down to preventing the introduction of the virus into the household and vaccination.

In prosperous areas, it is strictly not recommended to vaccinate chickens - this way you will introduce the virus to the farm for many years.

In practice, vaccination is only necessary in two cases:

• when importing vaccinated poultry from another farm;
• during an outbreak of infection and subsequent partial recovery of the herd.

There are not many vaccines against ILT. In a rural farmstead, it is advisable to use live vaccines. The best vaccination method is eye drops. The cloacal method is less effective, and drinking produces a large percentage of non-immune individuals.

Birds are immunized upon arrival at the farm or at 30-60 days of age. Chickens older than 60 days and adult chickens are vaccinated once, younger ones - twice with an interval between vaccinations of 20-30 days.

Vaccine overview

What do you need to know about ILT vaccines in general? There are two types of these drugs.

1. Vaccines produced in chicken embryos. They provide strong protection, but can cause serious complications.
2. Cell culture vaccines. They do not cause post-vaccination reactions, but provide lower protection.

All leading manufacturers have vaccines against ILT in their lineup. Here are several drugs recommended for use in laying hens and broilers. The minimum packaging in a bottle for most companies is from 1000 doses.

• Embryo vaccine against infectious laryngotracheitis of birds “Avivak ILT”, Russia.
• Dry virus vaccine against infectious laryngotracheitis of birds from the “VNIIBP” strain. “VNIVIP”, Russia.
• Virus vaccine against infectious laryngotracheitis of birds from the “VNIIBP” strain. “Pokrovsky Biological Preparations Plant”.
• Nobilis ILT. Live dry vaccine against infectious laryngotracheitis of birds with a solvent. Intervet, Netherlands.
• Vaccine for birds against infectious laryngotracheitis AviPro ILT. “Lohmann Animal Health”, Germany.

conclusions

Infectious laryngotracheitis- a serious viral disease. Chickens of all ages are susceptible to it. The main route of infection is the delivery of infected or vaccinated birds to the farm, so special attention is paid to stocking the flock.

When a disease occurs on the farm, the most The best way control - slaughter of all poultry, disinfection and import of new livestock. True, for such an extreme measure it is necessary to clearly know the diagnosis - to isolate the virus in the laboratory, which is not always possible in a private farmstead. Therefore, a method of partial recovery of the flock is used - weak birds are culled, and the rest are treated.

The decision on further vaccination also needs to be made based on the diagnosis made by the doctor - once you introduce the vaccine into the farm, you will be forced to bear the cost of vaccination for the entire future existence of the farm.

Source: http://webferma.com/pticevodstvo/veterinariya/infekcionnii-laringotraheit-u-kur.html

Laryngotracheitis is becoming an increasingly common infectious disease in chickens every year. Today the problem is relevant for England, Sweden, France, Yugoslavia, Holland, Italy, Canada, Indonesia, Hungary, Australia, Romania, USA, Poland, Spain, Germany, New Zealand, Russia.

Outbreaks are recorded in almost every region of these countries. Large poultry farms especially suffer from the infection, but small farms cannot avoid cases of laryngotracheitis. A breeder of any size must have an understanding of the pathology and how to cure it.

What is laryngotracheitis

Infectious laryngotracheitis is a respiratory disease. The causative agent is the Herpesviridae virus. Chickens are most often infected, but other poultry (pheasants, peacocks, and ornamental quails) are also susceptible to infection. Laryngotracheitis is also common among pigeons.

Infectious laryngotracheitis is a respiratory disease.

The first name of the disease is tracheolaryngitis. In 1925, it was discovered by Titsler and May in the USA. In 1931, parts of the name were swapped, as they remain today. The infection has long been compared with bronchitis, but has been relegated to the status of an independent problem.

The causative virus is survivable in any climate and resistant to many drugs. It can be quite difficult to defeat him, especially when it comes to complex forms of manifestation. Laryngotracheitis is expressed in impaired respiratory function. The infection is localized in the trachea and larynx, spreading to the conjunctiva, which causes lacrimation.

Outbreaks of mass infection are characterized by a seasonal pattern. They most often occur in spring and autumn at high humidity and low air temperatures. In winter, the virus actively settles in birds with low immunity.

The metabolism of harmful cells occurs slowly, so symptoms may not appear immediately, but up to 2 years from the moment of infection. Since poultry live in a group environment, the spread of the disease is rapid. Up to 80% of the flock can be affected in a day.

Recovered individuals acquire their own immunity, but spread the accumulated virus for a long time.

As a rule, transmission is carried out by airborne droplets with particles of cough sputum.

Even a person can become a carrier if chicken exudate gets on clothes or equipment.

The disease is transmitted to people through prolonged contact with infected livestock, but infection through meat, feathers and eggs is excluded.

Laryngotracheitis is not age-related, but it is more severely experienced by young animals up to the 100th day of life. In the northern regions, chicks up to 20 days of age often get sick. Recovered individuals acquire their own immunity, but spread the accumulated virus for a long time, so they cannot be introduced into an unvaccinated herd. Eggs from laying hens with laryngotracheitis are not incubated.

The disease is indirectly promoted by poor ventilation, too high humidity, drafts, unsanitary conditions in the chicken coop, unbalanced nutrition and vitamin deficiencies. The mortality rate from infection reaches 15%.

Economic damage from the disease

The appearance of laryngotracheitis on a farm is always associated with significant economic damage. The livestock often becomes ill completely or in a larger percentage. Many individuals die (especially young animals), which immediately deprives the breeder of a significant part of future meat production.

Due to outbreaks of laryngotracheitis, most of the livestock die, which incurs large losses.

In addition, the owner of the flock is forced to spend money on medicines, veterinarians, transportation of a specialist or birds to an appointment. Sometimes equipment needs to be replaced. A significant amount of money is spent on prevention – disinfectants, vaccines.

Symptoms of the disease

The laryngotracheitis virus spreads primarily to the mucous membranes of the nasopharynx, mouth and conjunctiva. The incubation period ranges from 1 to 3 days, but it happens that symptoms of infection appear by the end of the first day.

It happens that mycoplasmosis, colibacillosis, hemophilia, bronchitis or other bacteriological infections are associated with the disease. To confirm the diagnosis, an analysis for the isolation of viruses from the pathological material is necessary.

Important. Experts say that with a careful approach, laryngotracheitis can be suspected in 10-15 minutes, and cured in no more than a week.

Excessive lacrimation from the eyes, a runny nose, and a slightly open beak should immediately arouse suspicion in the owner.. Often, due to a swollen larynx, the bird experiences pain and refuses to eat. Among the general symptoms, blueness of the comb and earrings and noticeable weakness of the bird are also noted. Other signs depend on the form of the course.

With laryngotracheitis, chickens have watery eyes, they breathe heavily, and refuse to eat.

Symptoms of the hyperacute form

With this form, symptoms appear en masse and suddenly.

The signs are distinguished by their pronounced severity and rapid increase in intensity:

• Heavy breathing with whistling and wheezing, reaching the point of suffocation (increases at night).
• The bird stretches its neck and shakes its head in the hope of breathing more freely.
• Paroxysmal severe cough, often with bloody sputum.
• The chicken lies with its eyes closed a lot.
• In the poultry house there is mucus on the floor and walls.

The hyperacute form is considered the most deadly. It can kill up to 50% of the population. It is the most difficult to treat, since very quick measures are required.

Acute symptoms

The acute form of laryngotracheitis does not manifest itself as sharply as the hyperacute form. Chickens show symptoms several at a time at intervals.

• Passive attitude towards feedings and general activity.
• On examination, white curdled or slimy masses in the beak, redness, swelling of the mouth and larynx.
• Audible whistles when inhaling and exhaling.

At acute form chickens eat poorly and become apathetic.

The acute course is dangerous due to the blockage of the lumen of the larynx by accumulations of secretions. If an individual has an attack of suffocation, she needs urgent help in coughing up and relieving swelling. This form, without therapy or when it is insufficient, often develops into chronic. The mortality rate when receiving proper treatment does not exceed 10%.

Symptoms of the chronic form

Most of the time there are no symptoms.

They appear periodically and increase before the death of the chicken:

• Decline in weight gain and egg production.
• Repeatedly recurring attacks of spasmodic cough to the point of suffocation (even at long intervals).
• Conjunctivitis, sometimes photophobia.
• Frequent discharge of mucus from the nostrils.

When egg production drops, egg quality is preserved. Morbidity and mortality in chronic form are in the region of 1-2%.

With chronic laryngotracheitis, symptoms occur only occasionally.

Symptoms of the conjunctival form

Usually occurs in chicks 10-40 days old, but can also affect adult chickens:

• Inflamed, reddened whites of the eyes, photophobia.
• The presence of the third eyelid on the eyeball, sticking together of the eyelids.
• Mucus and foamy discharge from the eyes.
• Loss of orientation due to vision problems.
• Corneal fading.
• The trachea may be clogged with blood clots, and the mucous membrane of the throat is cherry-colored.

The conjunctival form is often curable within 1-3 months. The main danger is complete loss of vision due to atrophy of eye tissue.

Atypical symptoms

The atypical form of laryngotracheitis occurs unnoticed. As a rule, an individual carries and spreads the virus, but does not have obvious symptoms or danger of death. This happens with strong immunity or when the bird has already been cured.

The main symptoms can be seen only when examining the larynx - swelling, redness, small ulcers are possible due to the destroyed epithelium.

The atypical form of laryngotracheitis occurs unnoticed.

Treatment of laryngotracheitis in chickens

Therapy for laryngotracheitis is considered by many to be unjustified. From an economic point of view, it is considered more profitable to purchase new stock than to treat chickens in a sick flock. If old individuals are preserved, the virus will still remain on the farm and will spread to young animals, which will need to be vaccinated regularly.

Treatment of the disease is offered according to a nonspecific scheme:

1. Ensuring high-quality heating and ventilation in the poultry house, increasing the content of vitamins in the feed.
2. Drinking broad-spectrum antibiotics (tetracycline, norfloxacin, ciprofloxacin). Powdered furazolidone is mixed into the food (8 g of medication per 10 kg of feed).
3. Iodinated triethylene glycol, gentamicin, and lactic acid are aerosolized in the poultry house in the presence of livestock.
4. If it is possible to isolate the chickens, disinfection is carried out with a 15-minute distillation of a mixture of turpentine (2 mg) and bleach (20 mg) per 1 cubic meter of space.
5. They are given vitamin mixtures such as RexVital, Aminivital, Chiktonik, ASD-2 up to 1 ml per 100 chickens.

For laryngotracheitis, chickens are treated with antibiotics, for example Tetracycline.

Important. When slaughtering old livestock, the premises must be disinfected along with equipment before moving in new ones.

Prevention of disease

Prevention is carried out in three areas:

1. Maintaining sanitation in the poultry house, housing density, regular inspections, adequate feeding. Separation of livestock by age, quarantine of individuals before relocation. Periodic disinfection of the chicken coop with virocon or glutex when flocking.
2. The use of vaccines to develop immunity to the causative agent of laryngotracheitis. Cloacal, intraocular, oral, aerosol administration. In prosperous areas, vaccination is not recommended so as not to artificially cause outbreaks.
3. If infection is detected more than 2 times, the removal of chickens from the farm is prohibited by law.

Vaccine overview

There are two types of vaccines to prevent laryngotracheitis. The first ones are produced on the basis of chicken embryos. They provide strong immunity protection against a specific virus, but can cause serious complications in the body as a whole. For the second, the raw material is cell culture. Such varieties do not cause adverse reactions, but protection against them cannot be considered serious.

Some farmers vaccinate poultry with drugs against laryngotracheitis.

The most popular vaccines against infectious laryngotracheitis in the veterinary environment are those sold in packages of more than 1000 doses.

These include:

• Avivak, Russia;
• Intervet, Netherlands;
• AviPro, Germany;
• Vaccine from the VNIIBP strain, Russia;
• Nobilis ILT.

Source: http://ferma-nasele.ru/laringotraxeit-u-kur.html

Avian infectious laryngotracheitis (ILT)

Poultry ILT is a contagious respiratory disease of chickens of all ages, turkeys, pheasants. The disease was first described in 1925 by Meiel and Titsler as infectious bronchitis.

The virus was first isolated in 1930 by Beach and Bodet from the exudate and epithelial tissues of the upper respiratory tract of a sick bird.

A histopathological study carried out by Seyfried in 1931 showed that this disease mainly affects the larynx and trachea, and on this basis it was customary to call the disease infectious laryngotracheitis, a name that has remained to this day.

IN former USSR infectious laryngotracheitis was first described by R. Batakov in 1932, as well as many foreign authors under the name infectious bronchitis. Later A.P. Kiur-Muratov and K.V. Panchenko (1934), O.A. Bolyakova (1950), S.T. Shchennikov and E.A. Petrovskaya (1954) described it under the name infectious laryngotracheitis.

The disease has been registered in all countries with industrial poultry farming. Infectious laryngotracheitis causes very significant economic damage to poultry farming: with an unfavorable outcome due to the death of birds, forced slaughter and rejection, it reaches 80%.

When infected with infectious laryngotracheitis, a hen's egg production sharply decreases; pullets that have recovered from this disease at 4-5 months of age begin laying eggs very late. In addition, during illness, weight decreases, which has a particularly negative effect when fattening young animals.

Due to the long-term carriage of the pathogen by sick birds, infectious laryngotracheitis among new generations of chickens on the farm becomes stationary if appropriate control measures are not taken.

Pathogen– a virus of the herpesvirus family, DNA-containing, enveloped, virion size 40-100 nm. The virus is unstable to high temperatures, lipolytic agents, various conventional disinfectants: 1% NaOH solution, 3% cresol solution (inactivation in 30 seconds). The most effective is the aerosol application of formaldehyde.

In the autumn-winter period, the virus persists indoors for up to 10-20 days, and outdoors for up to 80 days. In the corpses of dead birds, the virus persists until rotting begins, and in frozen carcasses at -10-28°C for up to 19 months. In the tracheal mucus of sick chickens, the virus persists at 37°C for 40-45 hours. On the surface of the egg shell in a thermostat, the virus is inactivated within 12 hours.

In a lyophilized state, it can be stored for over 9 years.

Epizootology. Under natural conditions, chickens of all ages and breeds, including turkey and pheasant, are susceptible to ILT. Under experimental conditions it causes the death of 100% of non-immune chickens.

Z The destruction of birds occurs mainly by aerogenic means. In dysfunctional large poultry farms with a continuous poultry growing system, the disease can occur in a stationary manner with periodic outbreaks.

More often, the disease occurs in chickens and young chickens after transferring the poultry to a cold, damp poultry house, with insufficient ventilation, overcrowded planting, inadequate feeding, lack of vitamins and essential amino acids in the diet.

The disease is recorded in all seasons of the year, but its progression is aggravated during periods of sharp climatic fluctuations.

The source of infection is sick and recovered birds, as well as vaccinated and latently recovered birds, which secrete the virus of infectious laryngotracheitis throughout the entire economic use, since it remains in the body for up to 2 years. This explains the stationary nature of the infection.

The virus from a sick bird is released from the nasal cavity and trachea when coughing and with small droplets of exudate, the air flow can spread over a distance of up to 10 km. In addition, sick birds secrete a virus that can be found on the shells of eggs.

Under natural conditions, the portals of infection are the nasal and oral cavities, as well as the conjunctiva. Infection occurs through contact of a sick bird with a healthy one through feed and water contaminated with the virus, care items, shoes, and clothing of service personnel.

Placing a bird in a section of the house where a sick bird has recently been located and not properly sanitized leads to an outbreak of the disease. The sale of virus carriers and poultry with abortive and chronic forms of infection on the market often contributes to the spread of the disease.

Mechanical carriers can be rats and wild birds.

Chickens hatched from full-fledged hatching eggs are resistant to infectious laryngotracheitis in the first days of life. The virus is not transovarially transmitted, but can be found on the surface of the shell of eggs intended for incubation and is thus capable of infecting chickens.

In those poultry farms where the disease appears for the first time, it affects birds of all ages. On unfavorable farms, it is mainly young animals that get sick, since on unfavorable farms the adult bird acquires immunity; in chickens its presence is noted extremely rarely and it is expressed in a weak form.

Under natural conditions, depending on the virulence of the pathogen, the biological condition of the bird and the veterinary and sanitary state of the farm, young animals become infected starting from 20-30 days of age, but more often outbreaks of the disease are recorded in chickens aged 3 to 9 months.

Pathogenesis. The virus reproduces in the cells of the mucous membrane.

In the presence of a highly virulent strain of the virus, hemorrhagic inflammation occurs, accompanied by copious bleeding into the tracheal lumen - a hemorrhagic thrombus is formed, completely closing the tracheal lumen.

The bird dies from suffocation. During the period of inflammation, the blood virus spreads throughout the body and can be localized and reproduced in the cells of the conjunctiva and cloaca.

When a less virulent ILT virus enters the body, primary inflammation occurs in the tracheal mucosa, complicated by the activity of secondary microflora. A dirty gray plug forms in the trachea, closing the lumen. The bird dies from suffocation.

Clinic. The incubation period can last from 2 to 30 days and depends on the virulence and amount of the virus that has entered the body, and the resistance of the bird. The disease occurs hyperacutely, acutely, subacutely, chronically and abortively.

A hyperacute course, as a rule, develops when the disease first appears in a poultry farm and a highly virulent strain of the virus enters the flock. The disease begins suddenly and quickly (within 1-2 days) spreads throughout the flock, affecting up to 80% of the birds.

The death of the bird occurs on the second day after the disease.

Infectious laryngotracheal and respiratory symptoms are clearly expressed: depression, lack of appetite in the bird, coughing and signs of respiratory distress. When inhaling, the bird stretches its neck and a characteristic whistling sound is heard.

Through the open beak in the larynx one can see the hyperemic mucosa and fibrinous deposits on it, plaque in the mucous membrane of the mouth and pharynx. Frequent spasmodic coughing, continuous shaking and shaking of the head, or incessant attempts to get rid of suffocation are noted.

A debilitating cough is accompanied by the release of blood clots and mucous fluid. During coughing, mucus and blood clots may be released from the trachea. After this, the bird appears clinically healthy.

In most cases, conjunctivitis develops - the conjunctival sac is filled with causative masses. A sick bird's mass decreases and egg production drops by 30–50%.

The outcome of the disease is favorable and most birds recover when kept in premises with a good microclimate and high-quality balanced feeding.

Pathological changes. In the acute form, conjunctivitis is established, the tracheal mucosa is hemorrhagically inflamed, and there is a hemorrhagic thrombus in the tracheal lumen. In the subacute form, there is hyperemia, swelling of the tracheal mucosa and fibrinous plug.

A secondary inflammatory process develops, caused by the microflora of the air in poultry houses. First, cheesy diphtheria films are formed, attached to the larynx and the upper part of the tracheal mucosa.

Subsequently, mucous exudate accumulates in the trachea and nasal passage, diphtheria films somewhat melt under the influence of microflora. The resulting plug becomes dirty gray in color with brown streaks.

Diagnostics. The occurrence of an acute respiratory disease among birds on the farm, accompanied by difficulty breathing, wheezing, death of the bird from suffocation and the presence of hemorrhagic or caseous plugs in the tracheal lumen, allows for a preliminary diagnosis.

But often the disease occurs atypically or with mild symptoms. The final diagnosis is made on the basis of laboratory tests: isolation of the virus on EC and its identification by detection of intranuclear Seyfried inclusion bodies and serological methods - in RN, RDP, RIF.

The affected larynx, trachea, mucous membranes of the conjunctiva of the eyes from a forcedly killed bird in the first 7-10 days from the onset of the disease are used as virus-containing material for laboratory research.

During this period of time, virus isolation is most successful, and subsequently it is complicated by the layering of opportunistic microflora.

When making a diagnosis, exclude Newcastle disease, smallpox, infectious bronchitis, contagious runny nose, pasteurellosis, respiratory mycoplasmosis, vitamin A deficiency.

Newcastle disease affects birds of any age and is accompanied by high mortality. During a postmortem examination, hemorrhages characteristic of Newcastle disease are found at the border of the glandular and muscular stomachs.

Often hemorrhages and necrosis are found on the intestinal mucosa. The causative agent of Newcastle disease is a pantropic virus and is found in all organs and tissues.

When 7-9 day old chicken embryos are infected, a hemagglutinating virus is released into the chorioallantoic cavity after 12-48 hours.

Infectious bronchitis spreads among chickens up to 35 days of age. During a post-mortem autopsy, lesions of the bronchi and lungs are discovered. Infection of 9-day-old chicken embryos into the vallantoic cavity causes dwarfism or torsion.

A contagious runny nose is chronic. In the trachea and larynx there is no hemorrhagic and fibrinous inflammation, blood clots and caseous plugs. During bacteriological examination, the causative agent of a contagious runny nose is isolated - B.hemophilus gallinarum.

Smallpox is characterized by skin lesions and the presence of difficult-to-remove films on the oral mucosa. When 7-9 day old chicken embryos are infected, foci of necrosis are formed on the chorioallantoic membrane, similar to foci of necrosis caused by the infectious laryngotracheitis virus, therefore serological identification is necessary.

Pasteurellosis of the chronic form is differentiated by the detection of bipolar color-perceiving microbes in the blood smears of a sick bird. When sowing on simple nutrient media, they isolate Past.multocida, pathogenic for pigeons and white mice.

Respiratory mycoplasmosis is a slowly progressing disease, accompanied by minor mortality in birds. Often the corpses of dead birds are severely emaciated. During a pathological autopsy, damage to the air sacs is detected. When sowing, special nutrient media are isolated from the air sacs and lungs. M. gallisepticum.

With vitamin deficiency, the main changes are localized in the mucous membrane of the esophagus. Millet-like formations are found there. When chickens are infected with a suspension from tracheal exudate, the disease cannot be reproduced.

Elimination and prevention of disease Prevention of ILT consists of measures that provide for the protection of farms from the introduction of the pathogen. Flocks of birds are recruited from farms that are successful in terms of ILT; birds of different ages are placed in geographically separate areas: poultry houses are filled with birds of the same age.

Strictly observe inter-cycle preventive breaks with sanitization of premises, disinfect imported hatching eggs, containers and transport, ensure separate incubation of eggs imported and obtained from their own parent flocks; chickens obtained from imported eggs are raised separately from the rest of the poultry farm; create optimal zoohygienic, especially in relation to the microclimate, conditions of detention.

In poultry farms, poultry is widely used to prevent respiratory diseases by treating poultry with vapors of chlorine and turpentine, iodine triethylene glycol and antibiotics. The antiviral chemotherapy drug – isatizone, lozeval – has been successfully tested.

In the Russian Federation, two vaccines have been created from the live VNIIBP virus and a vaccine from the “NT” clone obtained from the TsNIIP strain. Vaccines are used in accordance with current instructions and methods of rubbing into the mucous membrane of the cloaca and aerosol. VNIVIP and VNIVViM have developed ocular and oral immunization methods.

Smallpox, NB, IB, colibacillosis and respiratory mycoplasmosis negatively affect the formation of post-vaccination immunity in ILT. To increase the effectiveness of specific prevention of ILT, it is necessary to take preliminary measures against these diseases.

Immunization of poultry against ILT 2-8 days after immunization against ND and smallpox causes a statistically significant decrease in the intensity of post-vaccination immunity against this disease.

In this regard, to increase the effectiveness of immunization against ILT, it is advisable to carry it out with an interval of 10-15 days before or after vaccination against NP and smallpox.

In an unfavorable farm, farm or zone, restrictions are introduced and actions are taken in accordance with the instructions for combating ILT. All healthy birds are immunized.

A negative factor when using a live virus vaccine is the potential for the spread of the virus and the appearance of a virus-carrying bird, which leads to widespread infection in the area.

Therefore, in areas where the disease is not endemic and an outbreak has occurred, it is worth resorting to replacing (slaughtering) the entire flock and carrying out thorough cleaning and disinfection before purchasing a new batch of poultry.

Restrictions are lifted 2 months after the last case of slaughter of sick and recovered birds, and completion of final measures.

Laryngotracheitis in chickens is an acute viral disease that affects the mucous membranes of the eyes, nose, pharynx, and trachea with predominantly hemorrhagic-catarrhal lesions.

There is no effective etiotropic treatment for laryngotracheitis. Symptoms and treatment are closely related, and all therapy consists of treatment to alleviate the bird's condition.

Basic principles of therapy:

1. Mandatory changes in the conditions of the poultry house: reduction of humidity, the room should be warm, good lighting. Replacement of bedding, disinfection of drinking bowls, feeders, enrichment of the diet.
2. To prevent the addition of microorganisms, broad-spectrum antibiotics are prescribed - tetracycline, enrofloxacin.
3. The room is treated with a spray containing lactic acid.
4. The oropharynx is treated with solutions containing gentamicin and furozolidone preparations.
5. The diet includes vitamin complexes: Chiktonik, Nitamin.
6. ASD-2 is used as an immunomodulator.

Prevention

The main aspect in preventing epidemics of laryngotracheitis is compliance with the conditions for introducing poultry to the farm. The collection of eggs for breeding and the purchase of poultry must be carried out from prosperous farms.

• The following conditions are also required: a dry, warm room with good ventilation. Overcrowding of poultry is unacceptable, and it is also recommended to separate the livestock by age.
• If the housing is carried out without walking, then it is necessary to treat the poultry house and also disinfect the air to free it from respiratory viruses.
• It is also timely to combat the appearance of rodents, which are mechanical carriers of dangerous infectious diseases.

During an outbreak of infection, it is strictly prohibited:

1. Moving domestic birds within the farm.
2. Import and export of poultry from the territory of the farm, as well as sale of eggs for incubation
3. Moving equipment, feeders and waste outside the farm.
4. Persons are not allowed to enter or leave the farm territory without first thoroughly sanitizing their clothing.

Important: Affected eggs and meat are allowed to be exported for sale after appropriate disinfection measures. Possible sale of down and feathers.

When chicken laryngotracheitis first occurs on a farm, it leads to the complete slaughter of the entire batch of poultry in order to prevent repeated outbreaks. Quarantine is lifted after two months from the date of death of the last sick individual.

Vaccination and drug review

If there is no outbreak of infection on the farm, then the birds are not vaccinated, since the chicken becomes a carrier of the virus and infects healthy fellow tribesmen.

The most famous option for vaccinating individuals is droppers of live serum. In second place in popularity is cloacal administration.

Immunization is carried out at the initial stages of detection of laryngotracheitis. Young animals up to 2 months are vaccinated 2 times with an interval of 1 month; for adult laying hens, one administration is sufficient. The duration of post-vaccination immunity ranges from 7 months to a year.

There are 2 types of drugs:

1. Isolated using chicken embryos.
2. Obtained from cell culture.

In the first case, the vaccine has the greatest effect, but has serious side effects. Cell culture preparations have less immunization of livestock, but without clinical manifestations of complications.

Avivak - vaccine Russian production, which is classified as the embryonic type.

VNIIBP – dry preparation. Isolated from a virus strain. Produced by a Russian company.

AviPro is a German live vaccine.

All medications are produced in dosages of at least 1000 doses per bottle.

Symptoms of laryngotracheitis in chickens

The infection is divided into three main forms:

1. Classic - laryngotracheal.
2. Conjunctival.
3. Atypical.

All forms are characterized by an incubation period that ranges from a couple of days to 1 month. But the height of clinical manifestations after infection occurs within 3-7 days.

According to the course of the disease there are:

1. Sharp form.
2. I'll sharpen the form.
3. Chronic course.
4. Asymptomatic course (virus carriage).

Laryngotracheal form

In its acute course, vivid clinical manifestations are observed first in individual laying hens, and within a week the disease affects the entire group of birds.

The disease begins with a general deterioration in health:

• Drowsiness;
• Lethargy;
• Apathy;
• Catarrhal phenomena;
• Damage to the respiratory system.

Main symptoms:

1. Cough, breathing problems: whistling, wheezing. They appear more often in the evening or at night, when croaking, whistling, wheezing breathing can be clearly heard from roosts in silence.
2. Mucous discharge mixed with blood from the nose and larynx.
3. Difficulty in inhaling and exhaling. The beak is constantly open, and when pressure is applied to the tracheal area, a paroxysmal cough begins with the release of blood-streaked sputum.
4. Upon examination, swelling and redness of the pharynx are noticeable, and in advanced cases, a cheesy coating may appear on the larynx.
5. Chickens stop laying eggs.

The lethal outcome depends on the conditions of detention and ranges from 10 to 60 percent of the total poultry population.

In the subacute course of the disease, the symptoms are less pronounced. There is no bloody exudate, edema, or sharp hyperemia of the larynx. The bird develops a cough, difficulty breathing, and a decrease in egg production. Anemia manifests itself - paleness of the earrings and comb. Upon examination, a fibrin gray coating is detected in the pharynx, which is easily removed.

Conjunctival form

With this type of disease, the main affected area is the mucous membrane of the eyes. In chickens, redness and narrowing of the eye slit, mucous flow, and swelling of the eyelids are observed.

Chicks of two weeks of age are most susceptible to this form, which, when kept together with adults, infect the entire population.

Main symptoms:

1. Eye damage: swelling, photophobia, lacrimation. When exudate appears, the eyelids stick together, the form is complicated by keratitis and panophthalmia with loss of vision.
2. Temperature increase.
3. Damage to the sinus node and the appearance of nasal discharge.

Typically, conjunctival laryngotracheitis lasts up to 3 months and greatly reduces the population of young animals. The form with eye damage occurs on farms with increased indoor humidity and increased concentration of ammonia fumes in the air.

Atypical form

Occurs together with bronchitis or mycoplasma infection. Symptoms are varied and masquerade as many types of respiratory infections.

This form is identified only during a serological blood test, after which a diagnosis of laryngotracheitis is made.

Diagnosis during pathological autopsy

The main clinical diagnosis is made based on the symptoms of the disease and autopsy of chicken carcasses.

Laboratory methods are also required:

• Serological examination of serum to detect antibodies;
• Isolation of the virus from exudate from the trachea and mucous membranes;
• Isolation of a biopsy sample from the mucosa to detect intracellular round-shaped inclusions of the virus with bright rims.

To study birds from all over the stream, up to 5 heads of live laying hens are delivered to the laboratory, as well as carcasses for dissection.

Pathological changes

All changes affect the respiratory system: larynx and trachea, without damaging other organs.

Symptoms:

1. The mucous membrane has bright hyperemia, edema, with pinpoint hemorrhages.
2. Fibrinous-necrotic plugs appear on the larynx, which close the lumen, causing death as a result of suffocation.
3. In the trachea a large number of mucus with bloody discharge.
4. There is a grayish coating in the oral cavity that comes off easily.

In rare cases, foci of necrosis are found in the lungs of a dead bird.

Differential diagnosis

Usually comparisons are made with pseudoplague, group A vitamin deficiencies (conjunctival form), mycoplasmosis, smallpox and viral bronchitis of chickens.

Peculiarities:

1. Pseudoplague is a characteristic lesion of the intestines, ulcers in the stomach with pathognomic rashes in the form of hemorrhagic rings on the mucous membranes.
2. Mycoplasmosis affects the lungs. Rarely leads to death.
3. Hypovitaminosis A is not expressed by attacks of suffocation.

It is difficult to distinguish the disease from smallpox; diagnosis is only possible using serological diagnostics and virus isolation.

Main routes of infection

Among domestic birds, pheasants, chickens, and turkeys are at greatest risk. More often, the virus affects young animals six months old.

If there is a lot of crowding, one-month-old chicks may get sick:

1. The main sources of infection are sick birds and virus carriers. The disease spreads throughout the farm through contaminated feed, water, contaminated bedding, and on workers’ clothing. The virus is released when a bird sneezes, coughs, or is mechanically transmitted through rats or wild birds.
2. If a bird has had laryngotracheitis, then it secretes virions in the environment. Such a bird must be culled, otherwise the disease becomes a permanent resident of the farm, infecting young birds.
3. Carriage of the virus after vaccination must be taken into account; it persists for about 2 weeks after administration of the serum.

Provided the eggs are properly raised in an incubator, newborn chicks are resistant to the virus.

The main reasons for the outbreak of the epidemic are the deterioration of living conditions:

• Poor ventilation;
• Poor nutrition;
• Excessive humidity.

Pathogenesis

The virus enters the body through damaged mucous membranes of the nasopharynx, larynx and eyes, causing an acute inflammatory process. The virus is most compatible with the epithelial lining of the respiratory organs, where the main factors of division and growth occur.

Such local exposure to virions causes lymphatic swelling of tissues and the appearance of exudative discharge. With the development of the disease, due to damage to the membranes of the respiratory tract, they turn hemorrhagic.

Despite the spread of infection through the bloodstream, other organs are not subject to pathological changes, and the entire process is localized in the larynx and trachea of ​​laying hens.

A secondary bacterial infection may occur, which begins to develop when necrotic plugs appear in the larynx.

A little history

The disease was first identified as a separate entity in 1925 in the USA. Before the discovery, the disease was no different from viral bronchitis. It was considered one disease.

The economic damage from the virus ranges from 10 to 30% in terms of reduced egg production and weight gain in laying hens. When poultry deaths are taken into account, costs vary.

And the frequency of deaths from the entire mass ranges from 15 to 50%. Poultry farms are also financially damaged by the costs of stopping the infection among the general flow of chickens.

Etiology

The causative agent of infectious laryngotracheitis in chickens belongs to the family of herpes viruses, which are round virions of the order of 100-250 nm in diameter.

The large variation in size is explained by fluctuations in the growth of virions in different environments: there are more of them in the cytoplasm of the cell than in the nucleus. The virus itself is DNA-containing and resistant to low temperatures. It remains frozen in poultry carcasses for more than 1 year.

But the infection is poorly susceptible to elevated temperatures. When boiled, virions die instantly, and when treated with chlorine-containing agents, they die within 30 seconds.

Sometimes lovers poultry They don’t have feathered pets because they are very concerned about their health and don’t know how to treat a sick chicken. Indeed, in most cases, a sick bird is treated the old fashioned way - with an ax. But we consider this a last resort; diagnosing the disease and curing the chicken is quite possible. Our articles are designed to help you in the fight against chicken ailments, and today it’s the turn to deal with such a scourge as laryngotracheitis in chickens - the symptoms and treatment will be described in detail in our article!

What is laryngotracheitis?

Laryngotracheitis is an acute infectious respiratory disease caused by a virus of the Herpesviridae family. Not only chickens, but almost all poultry and pigeons are susceptible to this disease. The virus infects the bird's larynx, trachea and conjunctiva, causing difficulty breathing and tearing. Laryngotracheitis is widespread everywhere, because poultry farms exist on all continents. The dangerous virus is stable and tenacious, which makes it much more difficult to fight it.

The original name of this disease is tracheolaryngitis, its authors were May and Titsler. In 1925 in the USA they discovered and described this disease. Later the name changed to infectious laryngotracheitis, this happened in 1931. At the same time, infectious laryngotracheitis was recognized as an independent disease, because before that it had long been compared with infectious bronchitis.

Infectious laryngotracheitis is characterized by some seasonality. Outbreaks of the disease can occur during the cold season. After all, the development and spread of the virus is facilitated by high humidity and low temperature.

At low temperatures, the virus in the external environment slows down its metabolic processes and persists longer. A chicken that has suffered laryngotracheitis and survived it will be a virus carrier for 2 years, so it is prohibited from contacting its relatives. The disease spreads very quickly, because chickens are creatures that live in large, close-knit groups. It is quite possible for about 80% of your flock to become infected in a day if you are dealing with a hyperacute form of the disease, which will be discussed in more detail below. Infection usually occurs through droplets of exudate that a sick chicken expels when coughing (airborne).

They contain a dangerous virus in high concentrations, which quickly spreads throughout the chicken coop, without knowing it, you yourself can become a carrier of the disease. If infected exudate gets on your clothes or equipment and you then go into a healthy chicken coop, unfortunately, the virus will most likely now settle there too. All age groups of birds, regardless of breed, are susceptible to laryngotracheitis. However, young individuals aged 60-100 days are most susceptible to the virus.

Symptoms

First of all, laryngotracheitis affects the mucous membranes of the bird, i.e., the mucous membranes of the nasal and oral cavities and the conjunctiva. The virus develops quickly and the first manifestations of the disease can be noticed within 24 hours. First of all, the bird's larynx swells and its eyes water; when pecking, the bird experiences pain. Therefore, she either refuses to eat altogether or eats with a noticeable slowdown. It is believed that an experienced poultry farmer is able to diagnose laryngotracheitis in 10 minutes and cure it in 5-6 days.

Otherwise, he can say goodbye to 15% of his livestock - this is precisely the mortality rate from this disease in its acute course. And the health of the surviving livestock and all subsequent ones will be at risk. Laryngotracheitis can occur in different ways; depending on the course of the disease, it is divided into acute, hyperacute and chronic. Let's look at the symptoms of each form separately.

Ultra-acute form	Acute form	Chronic course
As a rule, it occurs suddenly, infection of birds occurs rapidly, all symptoms are obvious. In the hyperacute form, the bird begins to breathe heavily, as if it is suffocating and stretches its head, trying to take a larger breath of air. Birds may have a severe cough that coughs up blood. Trying to overcome the attacks of suffocation, the bird shakes its head. The bird's general condition is depressed, it refuses to eat and behaves passively, usually standing with its eyes closed. In a poultry house where sick birds are kept, you may notice mucus discharge on the floor or walls. Particularly heavy breathing of birds is observed at night. With this form of laryngotracheitis, mortality is most likely; if measures are not taken, then within two days the first cases of death may be observed. As a result, laryngotracheitis can become fatal for 50% of the population.	The acute form begins and spreads not as sharply as the previous one. A bird affected by laryngotracheitis loses its appetite and sits with its eyes closed most of the time. The general condition of the bird can be described as lethargic and passive. Due to a tumor of the larynx, most of the time the bird breathes through its beak, and its breathing is labored, with wheezing and whistling. If you look into the bird’s oral cavity, you can see swelling and redness of the mucous membranes, and white spots on the larynx. If help is not provided to the chicken, due to the abundance of secretions, the trachea or larynx may become clogged and the bird will die from suffocation.	If the acute form of infectious laryngotracheitis is not treated, surviving chickens may develop a chronic form of the disease. The disease can be practically asymptomatic and only before the death of the bird can symptoms characteristic of laryngotracheitis appear. The chronic form can manifest itself as conjunctivitis. A modification of the bird's eye is observed; photophobia may develop in young birds. Due to such negative deformations, birds may lose their vision.

When diagnosing infectious laryngotracheitis, the first thing to pay attention to is the bird’s breathing. If you notice that when a chicken sighs, its tail feathers move, this is the first alarm bell. Any extraneous sounds that a bird makes when breathing should not go unnoticed. If, in combination with difficulty breathing, there is also inflammation and lacrimation of the eyes, then the chicken almost certainly has laryngotracheitis. When opening a dead chicken, modifications in almost all organs are visible to the naked eye, most of all, of course, the respiratory organs.

Treatment

The bad news is that a cure for laryngotracheitis has not yet been invented. Treatment is usually symptomatic with antibiotics. The drugs are not able to kill the virus completely, but can significantly reduce its activity, thereby helping the bird’s immune system fight the disease and easing the chicken’s general condition and the course of the disease. The main condition is to immediately begin treatment as soon as laryngotracheitis is detected in chickens. Biomycin and streptomycin in combination with trivit and furazolidone will provide significant assistance in the fight against laryngotracheitis.

Special attention should be paid to the diet of the chicken that is receiving treatment. Vitamins A and E will help the bird overcome laryngotracheitis by dissolving fat cells and thus destroying the beneficial habitat of the virus. In order not to deal with an unpleasant disease - laryngotracheitis, preventive measures are very important. Vaccination of young animals is used as a preventive measure, especially if you keep a decent number of livestock or own your own mini-poultry farm. Moreover, vaccination can be not only standard, but also cloacal.

To do this, apply the virus to the mucous membrane of the cloaca and gently rub it in. After a few days, the procedure should be repeated. After such a procedure, the mucous membrane becomes inflamed for some time, but now the chicken has immunity against laryngotracheitis.

Like any other disease, infectious laryngotracheitis will never visit your chicken coop if you provide your chickens with the right diet and care. Your chickens should have clean water and good quality feed, and the coop should be dry and well ventilated. Don’t forget about disinfecting the chicken coop; chlorine-turpentine is used for this purpose.

Video “Prevention of viral diseases of chickens”

An experienced breeder will tell you how to deal with viral diseases of chickens, which include laryngotracheitis, in the video below, which is presented to your attention!

Laryngotracheitis in chickens is a viral disease that affects the lining of the larynx and trachea. Additional symptoms are the occurrence of damage to the conjunctiva of the eye and nasal mucosa. If treatment is not timely, there is a significant loss of livestock.

What is laryngotracheitis in chickens

This disease is infectious and quite dangerous. Occurs due to viruses entering the body. The virus is stable; after passing the incubation period, it lives for several years in a fairly active state. Not only domestic chickens can suffer from laryngotracheitis, but also other poultry. Larengotracheitis has two main forms: acute and super acute.

The acute course of this disease brings up to 15% of the mortality rate of the livestock; the more acute course can account for up to 60% of the mortality rate. Sometimes this disease can occur in a chronic form. The most susceptible to this disease are young animals aged from 4 weeks to 8 months. This disease is dangerous for humans; the virus can be transmitted through contact with a sick bird.

Signs of infection with laryngotracheitis from chickens in humans

The larynx, trachea, and also the skin of the hands are affected, and bronchitis develops. This disease especially spreads during periods of large temperature changes between seasons with insufficient cleanliness in the chicken coop and with a low immune system in birds. A bird that has had laryngotracheitis has immunity and is no longer predisposed to this disease. But such a bird can be a carrier. The main route of transmission of the disease is airborne droplets.

Symptoms of laryngotracheitis in chickens

Laryngotracheitis occurs in 2 forms: acute and super acute. It is necessary to understand that the super acute form occurs only in those farms where the disease was previously identified and they are considered unfavorable for this disease. In the first days, infection occurs in up to 80% of the total population. The main sign of laryngotracheitis in chickens is the appearance of very heavy difficulty breathing. Then there is coughing, choking, and expectoration. A bird that has had this disease may wheeze for a long time and suffer from inflammation of the conjunctiva of the eye.

Symptoms beyond the acute course of laryngotracheitis in chickens

Firstly, attacks of suffocation appear, shaking of the head, a cough appears with bloody and other discharge, the larynx swells, curdled discharge appears on the mucous membrane, appetite disappears, egg laying decreases, and severe wheezing occurs.

Symptoms of acute laryngotracheitis in chickens

In the acute form of the disease, the respiratory system is affected, and spread throughout the entire population occurs within a week. If the disease is quickly detected and correct treatment is carried out, the mortality rate is low, usually not exceeding 20%. Signs indicating laryngotracheitis are decreased appetite, inactivity, lethargy, hoarseness and whistling are heard when breathing in birds, a cough is observed, when the larynx is swollen, there is a curd discharge, the conjunctiva swells. Sometimes, if not treated promptly, a bird may lose its vision.

How to treat laryngotracheitis in chickens

With this disease, the speed of treatment is important. For this disease in poultry farming there is not yet a necessary drug for treatment, but broad-spectrum antibiotics can be used that reduce the activity of the virus. An antibiotic such as biomycin significantly increases the safety of livestock; when using these drugs, it should be remembered that they are given in conjunction with vitamins. It is better to prevent this disease, so prevention is necessary, which includes a balanced nutritional diet and compliance with sanitary and hygienic standards in the chicken coop. Also, in the room where the poultry is kept, periodic disinfection is carried out using a mixture of chlorine and turpentine. Large poultry farms use a special vaccine against laryngotracheitis as a preventive measure.

Infectious laryngotracheitis in poultry

Infectious laryngotracheitis of birds is an acute, contagious disease mainly of chickens, characterized by damage to the larynx, trachea and eyes. The disease is caused by a filterable virus. The main source of infection is sick and recovered animals, which can be virus carriers for 2 years. The most susceptible are chickens and pheasants 15 days of age and older. Turkeys and pigeons suffer from laryngotracheitis. Unsatisfactory living conditions (overcrowding, dampness and poor ventilation) and inadequate diets predispose the disease.

The incubation period lasts about 3-10 days. Infectious laryngotracheitis occurs hyperacutely, acutely and chronically. A hyperacute course is characterized by a sudden outbreak and high mortality (up to 50-60%) of the sick bird. In an acute course, the death of about 10-15% of the population is observed, and in a chronic course, the mortality of birds is small (about 2-5%). Patients cough a lot, especially in the evening, wheeze, open their beaks, and have difficulty breathing. Egg production across the entire group of birds is reduced by almost half. Sick individuals sit ruffled, with their eyes closed and seem indifferent to everything around them. The mucous membranes of the larynx and trachea are often covered with films or a curdled mass, which, together with the exudate, makes it difficult for the bird to breathe, and therefore a wheezing sound is always heard in the poultry house. This feature is very significant, as it makes it possible without special labor make a diagnosis of laryngotracheitis. Experienced poultry farmers usually, after the bird sits on the roost, enter the poultry house and listen for wheezing, and if the farm is unfavorable for laryngotracheitis, then this becomes obvious 10 minutes after the visit.

With infectious laryngotracheitis, the conjunctival form is often observed, which is characterized by damage to the eyes and nasal mucosa. With this form, swollen eyelids are observed, photophobia is observed, the palpebral fissure is deformed, and animals huddle in a dark corner. The conjunctive form of infectious laryngotracheitis can most often be found in young animals from 15 to 40 days of age. The larynx and trachea in such chickens are almost not affected. With this form of the disease, a higher percentage of recovered chickens is observed.

No reliable therapeutic agents have been developed against infectious laryngotracheitis, but some authors recommend the use of symptomatic treatment aimed at helping the sick body during the course of the disease. An adult bird is administered intramuscularly with 20 thousand units per 1 kg of live weight of streptomycin with simultaneous intramuscular administration of trivit. Streptomycin is administered 2-3 times at 7-8 day intervals. At the same time, furazolidone is given with food at the rate of 20 mg per 1 kg of live weight for adult animals and 10-15 mg per 1 kg of live weight for young animals.

The room in which animals are kept is treated with chlorine-turpentine. The bird is removed from the room, then for each cube. m of room, take 5 g of bleach containing at least 25% active chlorine and 0.5 ml of turpentine. Aeration of the room should continue for at least 3-4 hours, and then the room is ventilated and filled with birds. Sometimes an iodine aerosol is used for each cube. m of room, take 0.3 g of crystalline iodine and mix it with 0.03 g of aluminum powder. The mixture is placed in cups or saucers and placed 10 m apart from one another. When a few drops of hot water are added, iodine begins to be released. Spend at least 30 minutes. Aerosol applications of iodine and chlorine are repeated after 4-7 days.

A quarantine is imposed on the farm, which is lifted 2 months after all necessary measures. General vaccination of birds from 25 days of age is carried out with a dry virus vaccine against infectious laryngotracheitis of chickens. The vaccine is diluted with saline solution in a ratio of 1:5 and 0.02-0.03 ml is rubbed into the mucous membrane of the upper fornix of the cloaca with an ocular corrugated glass spatula. Immunity occurs on the 7-10th day. A new dry virus vaccine has been developed from the VNIIBP strain. It can be vaccinated by aerosol or by rubbing it once into the mucous membrane of the cloaca. Aerosol vaccination is carried out according to the instructions included with the drug.

I. Petrukhin “Home Veterinarian”

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