Infection occurs through sick and recovered individuals. All types of chickens, pigeons, turkeys, and pheasants are susceptible to the disease. Chickens are most often infected with the virus.
A recovered bird carries the virus for up to 2 years. The spread of laryngotracheitis occurs due to poor living conditions for birds: poor ventilation, overcrowding, dampness, and poor diet.
What is infectious chicken laryngotracheitis?
Laryngotracheitis was first reported in 1924 in the USA. American researchers May and Titsler described it in 1925 and called it laryngotracheitis.
The disease was later described as infectious bronchitis. After the 1930s, laryngotracheitis and infectious bronchitis were recognized as independent diseases.
In 1931, it was proposed to call the disease of the larynx and trachea infectious laryngotracheitis.
This proposal was made in the Committee on Poultry Diseases. By that time, the disease had spread everywhere, including in the USSR.
In our country, infectious laryngotracheitis was first described in 1932 by R.T. Botakov. Then he called the disease infectious bronchitis. A few years later, other scientists described the disease under its modern name.
Today, chickens in many regions of Russia are infected with laryngotracheitis, causing enormous damage to personal and farm households. Birds die, their egg production and weight gain decrease. Poultry farmers have to spend a lot of money to stop the infection and purchase young animals.
Pathogens
The causative agent of laryngotracheitis is a virus of the family Herpesviridae, having a spherical shape.
Its diameter is 87-97 nm. This virus can hardly be called persistent.
For example, if there are no chickens in the poultry house, it dies in 5-9 days.
The virus persists in drinking water for no more than 1 day. Freezing and drying it preserves it, and when exposed to sunlight, the virus dies in 7 hours.
Kerazol alkali solutions neutralize the virus in 20 seconds. It can remain on egg shells for up to 96 hours. Without sanitization, it penetrates inside the egg and remains virulent for up to 14 days.
The herpes virus remains active in frozen carcasses for up to 19 months and in grain feed and feathers for up to 154 days. During the cold season, the virus lives outdoors for up to 80 days, indoors for up to 15 days.
Symptoms and forms of the disease
The main sources of the virus are sick and recovered birds.
The latter do not get sick after recovery, but 2 years after the illness they pose a danger, as they release the virus into the external environment.
Infection occurs through infected air.
The disease also spreads through slaughter products, feed, containers, feathers and down.
In this case, infection of the entire livestock occurs in the shortest possible time. The disease spreads most often in summer and autumn.
The course and symptoms of laryngotracheitis in chickens depend on the form of the disease, clinical picture, and conditions of keeping the birds.
The incubation period of laryngotracheitis is from 2 days to 1 month. Let us consider in more detail the main signs of the disease in each of the three forms.
Super acute
Often occurs where the disease has not previously manifested itself. When exposed to a highly virulent infection environment up to 80% of chickens can become infected in 2 days.
After infection, birds begin to breathe with difficulty, greedily swallow air, stretching their body and head.
Some chickens develop a severe cough, accompanied by expectoration of blood.
Due to the onset of suffocation, the chicken shakes its head violently, trying to improve its condition.
In a poultry house where sick chickens are kept, tracheal discharge can be seen on the wall and floor. The birds themselves behave passively, often standing in solitude with their eyes closed.
The course of hyperacute laryngotracheitis is accompanied by characteristic wheezing, which is especially audible at night.
If poultry farmers do not take action, after a couple of days of illness, the chickens begin to die one after another. The mortality rate is high - more than 50%.
Acute
In the acute form, the disease does not begin as suddenly as in the previous form.
First, several chickens get sick, and after a few days others become ill. A sick bird does not eat and sits with its eyes closed all the time..
The owners note lethargy and general depression.
If you listen to its breathing in the evening, you can hear coughing, whistling or wheezing sounds that are not characteristic of a healthy bird.
She has a blockage in her larynx, which leads to breathing problems and breathing through her beak.
If the area of the larynx is palpated, it will cause her to cough violently. Examination of the beak will allow you to see hyperemia and swelling of the mucous membranes. White spots called curdled discharge may be visible on the larynx.
Prompt removal of these secretions can help save the chickens' lives. After 21-28 days of illness, the rest may die from asphyxia due to blockage of the trachea or larynx.
Chronic
This form of laryngotracheitis is often a continuation of the acute form. The disease progresses slowly, with characteristic symptoms appearing before the birds die. Between 2 and 15% of birds die. People can also infect birds with this form due to unsuccessful vaccination.
A conjunctive form of laryngotracheitis is often observed, in which birds' eyes and nasal mucosa are affected.
It is more common in young animals under 40 days of age. With this form of the disease, the palpebral fissure in chickens is deformed, they become photophobic, and they try to hide in a dark corner.
With a mild form, chickens recover, but may lose their vision.
Diagnostics
The disease is confirmed after autopsy and laboratory tests.
To conduct a virological study, fresh carcasses, exudate from the trachea of dead birds, as well as sick birds are sent to specialists in the laboratory.
There, the virus is isolated from chicken embryos and subsequent identification is carried out.
A bioassay is also used on susceptible chickens.
During the diagnostic process, diseases such as Newcastle disease, respiratory mycoplasmosis, smallpox, and infectious bronchitis are excluded.
Treatment
Once the disease is diagnosed, treatment must begin.
There are no special drugs against laryngotracheitis, but symptomatic treatment can help sick birds.
Antibiotics can be used to reduce the activity of the virus and biomycin to reduce chicken mortality.
Also, for the treatment of infectious laryngotracheitis in chickens, like other birds, veterinarians use streptomycin and trivit, which are administered intramuscularly.
Prevention
Disease can be prevented in a variety of ways. Firstly, it is necessary to periodically disinfect the premises in which birds live.
However, they should be there. For disinfection, mixtures of chlorine-turpentine preparations and aerosols containing lactic acid are recommended.
Secondly, vaccination can be used. In regions with frequent outbreaks of the disease, a live vaccine is administered to birds through the nasal passages and infraorbital sinuses.
There is a possibility that under certain conditions these birds can become active carriers of the virus, so this measure is only a targeted prevention.
The vaccine can be rubbed into the feathers of birds or introduced into drinking water.
There is a vaccine specially developed for chickens from the strain “ VNIIBP" Typically, chicks are vaccinated from 25 days of age, taking into account the epidemiological situation.
If the farm is prosperous, aerosol vaccination is carried out. The vaccine is diluted according to the instructions and sprayed in the area where the birds live.
After this, a temporary deterioration in the condition of the birds is possible, which disappears after 10 days. The resulting immunity lasts for six months.
Another vaccination option is cloacal. Using special instruments, the virus is applied to the mucous membrane of the cloaca and rubbed in for some time. A few days later the procedure is repeated. After vaccination, the mucous membrane becomes inflamed, but after this a strong immunity is developed.
In a household in which laryngotracheitis is diagnosed, quarantine is introduced. It is not allowed to export chickens, equipment, feed, or eggs.
If the disease appears in one poultry house, all chickens are sent to a sanitary slaughterhouse, after which the premises are disinfected and biothermal disinfection is carried out. In poultry farms, entry and exit of people from the premises is permitted after thorough sanitization of shoes.
Thus, laryngotracheitis is a dangerous infectious disease of chickens, which every poultry farmer should know about. By recognizing the disease in time, you can save laying hens from suffering and premature death.
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 experiences 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.
Typical symptom: hemorrhagic tracheitis (bleeding into the trachea), which occurs with laryngotracheitis - 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.
Caseous plug in the larynx formed as a result of laryngotracheitis - 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"
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.
It is important to note that laryngotracheitis has the following forms of occurrence:
- spicy;
- pre-acute;
- conjunctival;
- atypical.
Acute laryngotracheitis
The disease in this form begins suddenly. Initially, symptoms are observed in just one bird, and after a week the disease spreads throughout the chicken coop. The acute form develops quite quickly and requires timely treatment.
Preacute laryngotracheitis
The disease in this form can last from 2 to 3 weeks. In this case, the symptoms are not as severe as in the acute form. At the end of the disease, the chicken recovers. In some cases, preacute laryngotracheitis may progress into a chronic form. In other words, the chicken will be sick for about a month with periodic improvements.
Conjunctival form
In this case, in addition to the general symptoms of laryngotracheitis, suppuration of the eyes is added to the disease. Sometimes the damage to the eyes can be so severe that the chicken goes blind after recovery.
Atypical form
This form is practically asymptomatic. Usually, owners notice the disease only when the bird’s condition deteriorates critically. At the same time, a sick chicken manages to infect almost the entire population of the chicken coop. Most often, the atypical form occurs in combination with other diseases.
How does the disease affect the chicken?
When infected with laryngotracheitis, chickens become lethargic and their appetite is impaired. Very often observed. In young chickens aged 20-30 days, the virus can infect. In this case, bacterial conjunctivitis develops. Normalization of the bird's condition occurs within 12-14 days with timely and correct treatment.
Causes of infection
The causes of infection are quite banal. Most often, the virus enters the chicken coop in the following way: when purchasing birds from an unverified breeder. You can buy a bird whose disease is in the incubation period. By placing a chicken with others, it automatically becomes the main source of infection.
In addition, you can purchase a bird that has already recovered from the disease, which is a source of virus release, but itself has a strong immunity to the disease. In simple words, in birds the virus is transmitted exclusively from individual to individual.
Treatment methods
Treatment of laryngotracheitis is carried out in the following ways: 
- in order to prevent complications in the form of bacterial infections from joining laryngotracheitis, the bird is given water. More effective drugs are enrofloxacin, furazolidone and tetracycline;
- carry out disinfection of the chicken coop using an aerosol spray of lactic acid;
- drink vitamin complexes to boost immunity and the body’s defense reactions;
- for the prevention of healthy livestock are carried out.
Traditional methods include:
- providing chickens with access to green food;
- frequent ventilation of the chicken coop in warm weather;
- heating in winter.
Step-by-step instructions for using drugs
Enrofloxacin
It is used exclusively orally. To use the drug, it is diluted with water in a ratio of 5 ml per 10 liters of water and placed in the chicken coop instead of ordinary water. Usually the course of treatment does not exceed 5-7 days.
Furazolidone
It is important to note that an overdose of this drug can be fatal to birds, which is why it is recommended to consult a veterinarian before starting to take the medication.The drug must be given in a ratio of 3-5 mg per chicken, respectively, the larger the bird, the larger dose of the drug it will need. The course of treatment with furazolidone lasts 8 days.
Tetracycline
The calculation of the medicine is carried out according to the formula 50 mg of the drug per 1 kg of body weight of the bird. The drug is mixed with a small amount of food and divided into two portions: one is given in the morning, the second in the evening. Treatment with tetracycline continues for at least 5 days.
Consequences of the disease
Despite the fact that laryngotracheitis has a low mortality rate among chickens, the disease nevertheless has its consequences.
After a chicken gets sick, it develops a strong immunity to the virus, but the virus itself continues to live in the bird’s body and is released into the air through its breath. Thus, even after recovery, the chicken remains infectious to other birds.As for young chickens, laryngotracheitis can cause blindness in them due to conjunctivitis.
Laryngotracheitis – in poultry, the development of which is provoked by a virus from the order Herpesviras. The disease affects the mucous membranes of the upper respiratory tract, eyes and nose.
If treated incorrectly or untimely, the disease is fatal: during the epidemic, 10 to 60% of the chicken population dies.
The virus that causes laryngotracheitis is transmitted by airborne droplets or contact. Birds can become infected through water, bedding, feces and care items. And the more crowded laying hens live, the higher the risk of rapid spread of the epidemic (outbreaks of the disease are especially dangerous on broiler farms, where more than 10 birds live per 1 m2).
Young animals aged 30 to 100 days are especially susceptible to the virus.
There are several forms of laryngotracheitis:
- hyperacute (spreads in 2–3 days and kills up to 50–60% of the population);
- acute (spreads in 8–10 days and kills up to 15% of the livestock);
- subacute (characterized by mild symptoms, fatal for 5–10% of the population);
- chronic (rare and characterized by a slow increase in symptoms and low mortality - from 1 to 10%);
- asymptomatic.
Chickens that successfully survive the disease become lifelong carriers of the virus. For them, the virus is no longer dangerous: re-infection is impossible. However, such a bird can infect its relatives.
The virus is also dangerous for humans. If a farmer often comes into contact with sick birds, he may develop inflammation of the larynx and trachea, and occasionally rashes appear on the skin of the hands. At the same time, the virus is not transmitted through poultry products - meat, eggs and feathers.Causes of the disease
The direct cause of the epidemic outbreak is the entry of the virus into the body of individual chickens. Improper living conditions for birds can facilitate the spread of the disease:
- non-compliance with sanitary standards and irregular cleaning and;
- increased humidity and dust in the air in the chicken coop;
- poor and lack of ventilation;
- unbalanced diet;
- decreased immunity in chickens.
Symptoms of laryngotracheitis
After the virus enters the bird’s body, 6–8 days must pass for the first symptoms of the disease to appear. The length of the incubation period depends on the immunity of the bird and the sanitary conditions in the chicken coop.The signs of the disease are:
- difficulty breathing, wheezing and gurgling in the larynx, attacks of suffocation that occur due to severe inflammation and swelling of the trachea;
- the appearance of a cough, in which mucous fluid with bloody splashes may be released from the larynx;
- inflammation, swelling and redness of the larynx, the appearance of white or pinkish cheesy discharge and pinpoint hemorrhages on the walls of the throat;
- the appearance of mucous and foamy discharge from the nose and eyes, redness of the mucous membrane of the eye, the development of conjunctivitis, and subsequently panophthalmia;
- drop in poultry egg production by 30–50%;
- lethargy, inactivity, lack of appetite;
- bluishness of the ridge.
The symptoms of laryngotracheitis manifest themselves most clearly in acute and hyperacute forms. In all other forms, the picture of the disease is erased (the chicken has a slight cough, sneezing, inflammation) or is completely absent.
A veterinarian can make an accurate diagnosis after laboratory tests. The material for analysis is scrapings from the walls of the larynx, discharge from the eyes and nose, as well as carcasses of dead birds.
The illness lasts from 14 to 18 days. If the treatment was intensive and timely, the chicken may recover. Otherwise, death is guaranteed.
Treatment of laryngotracheitis
Chickens infected with laryngotracheitis are usually not treated: this is not feasible from an economic point of view. Most often, farmers send all their livestock to slaughter, disinfect the chicken coop and bring new individuals to the farm.If slaughter of the entire livestock is not possible, partial recovery is practiced. The farm owner sorts the birds: sick, weakened and emaciated individuals are sent to slaughter, and the rest are treated with aerosols. This approach allows saving up to 90% of the bird population, but it is associated with serious material costs.
Supportive and symptomatic therapy
To help chickens recover faster, it is recommended to carry out the following activities: 
- provide birds with high-quality food;
- artificially fortify food and water with liquid vitamins A and E;
- heat and regularly ventilate the chicken coop;
- disinfect the poultry house in the presence of chickens;
- feed the birds with a weak disinfectant solution of potassium manganese (1 ml per 10 liters of water);
- lubricate the larynx of sick birds with a 2% solution of protargol or a mixture of glycerin and iodine (for 10 ml of glycerin, 1 ml of 5% iodine solution).
In addition to maintenance therapy, the chicken also needs drug treatment. Good results are achieved by the simultaneous use of antibiotics, antimicrobials (furazolidone), antiseptics (ASD-2) and aerosols with a disinfectant effect.
Drug therapy
The most popular treatment method for laryngotracheitis is antibacterial therapy. The following drugs are used to treat chickens:
- Biomycin. The drug is used in two ways: orally and intramuscularly. Medicine is added to water at the rate of 1 mg per 1 liter of water. This dose should be divided into three parts and given to the birds throughout the day. Course duration – 5 days. To administer the drug intramuscularly, dilute 2–3 mg of the drug in 2 ml of water per bird. Biomycin is administered three times during the week.
- Penicillin. Using a pipette, the drug is injected into the chicken's beak at the rate of 100–200 thousand units per 1 kg of weight. Penicillin is taken 3-4 times a day with an interval of 6-8 hours. The course of treatment is 3–4 days.
- Streptomycin. The drug is administered intramuscularly at the rate of 20 thousand units per 1 kg of body weight. Treatment is carried out once; if the chicken has not recovered, re-treatment is carried out after 7-8 days.
- Tromexin. The drug is diluted in water (2 g per 1 liter of water on the first day and 1 g per 1 liter of water on the second day and further) and fed to chickens for 3–5 days. In the early stages of the disease, the medicine gives good results.
Other medications are also used:
- Furazolidone. The drug is added to the feed or injected into the bird's beak with a pipette: 2 mg for chickens under 10 days of age, 3 mg for chickens aged 10–30 days, 4 mg for adult laying hens. The dose is divided into 3 parts and fed to the birds throughout the day with a break of 7–8 hours. The course of treatment is 10 days.
- ASD-2. It is added to wet food (35 ml of the drug per 100 liters of food) and fed to birds daily for 5 days.
Aerosol spraying
Disinfection of premises using aerosols is also very popular. The following means are used: 
- Iodotriethylene glycol. To obtain 1 liter of the drug, mix 160 g of potassium iodide, 300 g of crystalline iodine, ground into powder, and 915 ml of triethylene glycol. Then the drug is combined with 1 liter of water and sprayed from a sprayer in the presence of chickens (1 liter per 1 m3). The composition not only disinfects the room, but also clears the respiratory tract of birds. 4 treatment courses are carried out for 2–3 days each (with a break of 2–3 days).
- Chlorine turpentine. Combine the components at the rate of 2 g of bleach and 0.5 g of turpentine per 1 m3, pour the composition into small basins and place them in different corners of the room. The components react, and the air in the poultry house is filled with vapors of chlorine and turpentine. Spraying is carried out once in the presence of birds (ventilation must be turned on). Spraying time – 15 minutes.
- Isation. The solution is sprayed from a sprayer in the chicken coop in the presence of chickens at the rate of 1 ml of the drug per 1 m3 (for chickens aged 10–30 days), 1.5 ml per 1 m3 (for chickens aged 30–60 days), 2 ml per 1 m3 (for chickens over 60 days old). The bird must remain in the room treated with isathion for at least 40 minutes. 4 courses of treatment are carried out for 3 days with a break of 10–12 days.
- Iodine. Mix 0.3 g of crystalline iodine with 0.03 g of aluminum powder. This dose is calculated for 1 m3 of chicken coop. Chickens are kicked out of the poultry house. The drug is poured into cups, placed at a distance of 10 m from each other and hot water is dripped into them. The iodine begins to evaporate and disinfect the air. The procedure is carried out for 30 minutes and is repeated twice with an interval of 4–7 days.
Prevention
There are two types of preventive measures: direct () and indirect. In regions where outbreaks of laryngotracheitis are rarely recorded, preference is given to indirect preventive measures:
- compliance with sanitary rules for keeping poultry;
- proper placement of chickens and avoiding “overcrowding” of the poultry house;
- separate keeping of adults and young animals;
- regular veterinary examination of birds;
- isolation and examination of chickens with suspicious symptoms;
- regular cleaning and disinfection of the chicken coop;
- balanced feeding of birds with food high in vitamin A.
Vaccination of birds is carried out in regions with frequent outbreaks of the disease.
Vaccination against laryngotracheitis is dangerous for chickens: a bird that has received immunity becomes a lifelong carrier of the virus and turns out to be potentially dangerous for unvaccinated inhabitants of the chicken coop. If such a laying hen gets into a poultry house with unvaccinated chickens, outbreaks of laryngotracheitis will begin there.Vaccination is carried out either when the bird arrives at the farm or when it reaches the age of 30–60 days. Birds over 60 days old are vaccinated once; if vaccination is carried out earlier, then the vaccination must be repeated after 20–30 days.
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; an extremely 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 sight.
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 nutritionally balanced 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 preventative measure.
