What is infectious chicken laryngotracheitis and can it be cured? Laryngotracheitis in chickens - treatment and symptoms of the disease (2018).

Affects the mucous membrane of the larynx and trachea. Sometimes concomitant symptoms are conjunctivitis and nasal lesions. If the disease is not cured in time, you can lose many of your domestic laying hens. Let's consider laryngotracheitis in chickens, the treatment of which is so important to start on time and correctly.

Laryngotracheitis is a dangerous infectious disease that is caused by the activity of viruses from the herpes family. As practice shows, it is quite stable, so after the incubation period it can remain active for up to two years. In addition to chickens, all poultry, as well as pigeons, suffer from this disease.

Laryngotracheitis in chickens occurs in two main forms: acute and hyperacute. At the same time, the acute course of the disease causes mortality in 15% of cases, while the hyperacute form causes mortality in 50-60% of cases. In some animals, the disease occurs in a chronic form.

Chickens of all poultry, and especially chickens aged 30 days - 8 months, are the most susceptible to the disease. It is important to note that the virus can also be transmitted to humans if they frequently come into contact with infected birds. A person may be affected by the larynx and trachea, the skin of the hands, and also develop bronchitis as a result of the disease.

As for chickens, laryngotracheitis most often manifests itself during periods of unstable temperatures, the off-season, when sanitary standards are not observed, and also when the birds’ immunity is low. Old and adult birds that have suffered from the disease at an early age acquire immunity, so they no longer get sick. But they are carriers of the virus. The main route of infection is airborne.

Symptoms of manifestation

As we have already said, laryngotracheitis occurs in chickens in two phases - acute and hyperacute. The latter form often occurs suddenly in disadvantaged farms where the disease has not previously been recorded. In this case, almost all chickens (up to 80%) can become infected in the first day. The main indicator of this disease is the bird’s heavy, almost impossible breathing. Afterwards a cough appears, attacks of suffocation, and hawking. Birds that have recovered from the disease may continue to wheeze for a long time and suffer from conjunctivitis, although they will look healthy outwardly.

Symptoms of the hyperacute form

• attacks of suffocation;
• chickens shake their heads;
• cough with blood or other discharge;
• low mobility of birds;
• swelling of the larynx and the presence of curd-like discharge on the mucous membrane;
• lack of appetite and egg laying;
• wheezing.

Symptoms of the acute form of the disease

Laryngotracheitis in its acute form also affects the respiratory system and spreads throughout the herd in about 10 days. Mortality in these cases with proper treatment is low, does not exceed 20%. Characteristic features:

• poor appetite;
• lethargy and inactivity;
• wheezing and whistling when breathing;
• cough;
• swelling of the larynx;
• presence of cheesy discharge.

In chickens, laryngotracheitis is also accompanied by a severe form of conjunctivitis. Many even lose their sight.

Treatment methods

If laryngotracheitis is detected in chickens, treatment should be carried out immediately. However, we note that a drug to combat bird disease has not yet been created. Various antibiotics are used in practice, which can only reduce the activity of the virus. For example, the use of biomycin reduces overall mortality. When taking medications, laying hens must receive additional vitamins in their diet, in particular A and E.

Sometimes poultry lovers do not have feathered pets for the reason that they are very concerned about their health and do not 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.

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!

Poultry infectious laryngotracheitis affects chickens, turkeys and pheasants. It is characterized by acute progression and hemorrhagic inflammation of the mucous membrane of the trachea, larynx, and sometimes the conjunctiva of the eyes and the death of the bird from suffocation.

Most often, avian laryngotracheitis affects young birds over 1 month of age, but adult birds also suffer greatly from this disease. Therefore, we invite you to talk about the symptoms of laryngotracheitis in chickens and how to treat poultry laryngotracheitis.

Infectious laryngotracheitis of chickens: the causative agent is a virus

The causative agent of this is a virus of the herpes family measuring 87-110 nanometers. The virus is not resistant to elevated temperatures: at a temperature of 55 0 C it dies in 10 minutes, at a temperature of 60 0 C - in two minutes. At low temperatures it remains virulent for quite a long time: at -20 0 C - up to 105 days, at -8-10 0 C - up to 210 days. At the same time, in frozen carcasses of sick slaughtered poultry, it retains its activity for 1-1.5 years, at room temperature - up to 30 days. In contaminated water chicken infectious laryngotracheitis virus lives no more than 24 hours, in a chicken coop without birds - 6-9 days, in litter during biothermal treatment it is destroyed after 10-15 days.

The avian laryngotracheitis virus dies in 1-2 minutes under the influence of 1% sodium hydroxide solution, 3% creosote solution, 5% phenol solution. In the presence of birds, it is recommended to use aerosol preparations based on quaternary ammonium compounds.

Infectious laryngotracheitis of chickens: how to get infected

The source of infection is a sick bird, as well as one that has recovered from the disease, since it can carry the virus for up to two years. The main method of transmission of the laryngotracheitis virus in chickens is aerogenic. The pathogen can spread through infected feed, equipment, water, and dust. In addition, beetles that are pests of feed can be carriers of the virus.

The mortality rate from infectious laryngotracheitis in poultry is 2-75%. Since recovered chickens, guinea fowl, pheasants and turkeys carry the virus for quite a long time, the infection can be very difficult to remove from the farm. In addition, modern vaccines do not guarantee protection of poultry from virus carriage of vaccine strains and their further reversion to virulent ones.

Infectious laryngotracheitis of chickens: symptoms

This virus multiplies in the epithelial cells of the larynx and trachea, causing acute serous-hemorrhagic inflammation with the phenomena of “peeling” of the epithelium and serous edema of the submucosal membrane. In some cases, the disease is complicated by the penetration of a secondary infection, while fibrinous plaque develops on the affected mucous membranes, and degeneration of the epithelium is observed.

The incubation period for infectious laryngotracheitis in poultry lasts from 3 to 15 days. There are two main forms:

- Laryngotracheal - classic form. Symptoms of chicken laryngotracheitis in the classic form: the bird stretches its neck, the neck becomes thicker (swells), breathes with an open mouth, heavily, sometimes “croaking” sounds are heard.

- Atypical (non-typical) form . Symptoms of chicken laryngotracheitis in the atypical form: the bird has conjunctivitis, panophthalmia (the cornea becomes cloudy, collapses, the eyeball protrudes from the orbit, the bird goes blind), rhinitis.

Poultry infectious laryngotracheitis can occur in three clinical forms:

• Acute form. Accompanied by a sudden appearance and lightning-fast spread. At the same time, there is a high incidence of poultry, mortality reaches 50%. In some chickens with an acute form of infectious laryngotracheitis, typical symptoms may not be observed: she does not stretch her neck, or shortness of breath is not heard. At the same time, the chickens cough and wheeze, trying to remove the obstruction from the trachea. On the walls and floor of the chicken coop you can see blood clots that the bird coughs up. At autopsy, the main changes are observed in the upper part of the respiratory tract and are characterized by hemorrhagic tracheitis, mucous rhinitis and the layering of diphtheria films mixed with blood along the entire length of the trachea.

• Subacute form . With this form of infectious laryngotracheitis in chickens, the appearance of respiratory symptoms is observed after a few days. The incidence is also high, but the mortality rate is slightly lower - 10-30%. When opening carcasses, pathological changes are less pronounced than in the acute form: in the trachea, in the area of ​​the respiratory slit, hyperemia, swelling of the mucous membrane, minor hemorrhages, accumulation of foamy, serous-hemorrhagic exudate are noted. Fibrinous-caseous deposits in the larynx are easily removed, and inflammation of the infraorbital sinuses and conjunctiva is observed.

• Chronic or moderate form . This form of infectious laryngotracheitis in chickens is most often observed in birds that have had an acute or subacute form. Mortality in one flock does not exceed 1-2% - as a rule, from strangulation. The chronic form of poultry laryngotracheitis is characterized by suffocation, coughing, discharge from the nose and beak. Outbreaks of a moderate form of infection can affect a large number of birds at the same time. Sometimes lesions develop in the form of sinusitis, conjunctivitis, and serous tracheitis. When opening a bird, diphtheria and necrotic plaques are found in the trachea, larynx, and oral cavity.

Infectious laryngotracheitis of chickens: treatment and prevention

For specific prevention, birds use the following drugs:

Virus vaccines “VNIIBP-U”, “Embryo vaccine from strain O” (Ukraine)

Live ILT vaccine (Israel)

- “TAD ILT” virus vaccine (Germany), etc.

Immunity is formed in 4-5 days and lasts about 1 year. When there is a threat of infection with laryngotracheitis, chickens are vaccinated no earlier than at 17 days of age.

Before, how to treat infectious laryngotracheitis in chickens, the sick bird is placed in a separate room, but both sick and healthy birds are treated.

Treatment of infectious laryngotracheitis in birds It is recommended to administer blue iodine with food, as well as inhalation of aluminum iodide or triethylene glycol.

To do this, take a mixture of powdered iodine, ammonium chloride and aluminum powder, place it in metal glasses, which are placed evenly around the house, and then add water to each glass (at the rate of 2 ml per 10 grams of powder, 1.2 grams of powder is enough for processing 1 cubic meter of room). In this case, the bird is not released from the house while the reaction continues.

Our article provides a simplified, more realistic procedure for treating a room. We quote:

Treatment of cough and wheezing in chickens It begins with the fact that the sick bird is urgently isolated, and the healthy bird and the premises are disinfected. For this purpose, iodine monochloride and aluminum are used. You can also find crystalline iodine in the advice, but it is no longer sold in pharmacies. Therefore, we take 10 ml of iodine monochloride (yellow liquid with a pungent odor) and mix it in a ceramic bowl with 1 gram of aluminum (you can take silver paint or an aluminum dart). As a result of the reaction, yellow smoke is released, place the dishes in the chicken coop with the chickens and close it. The smoke does not last long, about 10 minutes. The dose is indicated for a room of 10 “squares”. The procedure should be repeated several times with an interval of 2-3 days and be sure to give the chickens an antibiotic as described in the section on prevention.

In this case, it is best to take tetracycline antibiotics or drugs based on Tylosin. There are drugs that combine both active ingredients (for example, Bi-septim). An antibiotic should be given to all birds on a farm where there are chickens, pheasants, turkeys, guinea fowl with laryngotracheitis, or where this infectious disease is suspected, in order to protect the bird from possible complications. Antibiotics are given or given with food, depending on the manufacturer’s recommendations.

However, when treating birds, you should not take drugs that irritate the mucous membrane of the respiratory tract, such as formaldehyde, turpentine chloride, etc.

Sick birds must be slaughtered and disposed of.

Tatyana Kuzmenko, member of the editorial board, correspondent of the online publication "AtmAgro. Agro-industrial Bulletin"

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; in the external environment its resistance is low - it can persist for several weeks on care items, clothing of service personnel, feeders and drinkers, and 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 autopsying a dead bird, a characteristic sign is 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 is 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.

If a disease occurs on a farm, the best way to combat it is to slaughter 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.

In the 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.
• Fading of the cornea.
• 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.

Disease prevention

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 the 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 is a disease that occurs as a result of a virus entering the body. Chickens are predominantly affected by laryngotracheitis, especially on large farms. The virus affects the larynx and trachea; in rare cases, the bird may develop conjunctivitis or have problems with nasal breathing.

Outbreaks of this disease are recorded in all parts of the globe, regardless of climatic conditions. Most often, laryngotracheitis occurs between 40 and 100 days of age.

Like any other disease, laryngotracheitis has its own distinctive symptoms, which include:

• and whistling while breathing;
• when the chest is compressed, the chicken begins to cough;
• mucus may be discharged from the eyes and nose;
• when examining the larynx, the veterinarian may detect swelling and redness, as well as pinpoint hemorrhages on the mucous membrane;
• Clots of sputum may be observed on the walls of the larynx.