Beware of infectious laryngotracheitis in winter and spring

Chicken infectious laryngotracheitis is an acute respiratory infectious disease caused by herpesvirus. It is characterized by dyspnea, coughing and exudation containing blood. The disease spreads quickly and the mortality rate is high, which endangers the development of chicken industry.

The disease can occur all the year round, but it occurs frequently in winter and spring.

Infectious laryngotracheitis virus mainly exists in tracheal tissues and exudates of diseased chickens. The resistance of the virus to the external environment is very weak. Heated to 37 ℃, the virus survived 22 ℃ for 24 hours, 55 ℃ for 10 ℃ for 15 minutes, and died immediately after boiling water. Disinfect it with 3% Lysol or 1% caustic soda disinfectant and kill it in 1 minute.

Epidemic characteristics under natural conditions, the disease mainly affects chickens, and all ages and breeds can be infected, but the symptoms of adult chickens are the most characteristic. Diseased chickens and recovered infected chickens are the main sources of transmission, usually through respiratory tract and intraocular transmission. Bedding grass, feed, drinking water and utensils contaminated by respiratory organs and nasal secretions can become infectious agents.

Once the disease is introduced into chickens, it spreads rapidly, and the infection rate can reach more than 90%. The mortality rate varies according to feeding conditions and the condition of the flock, ranging from about 5% to as high as 50% and 70%.

The incubation period of natural infection of clinical symptoms was 6 Mel 12 days. The diseased chicken had nasal juice in the initial stage, which was translucent, with tears in the eyes and conjunctivitis. It was followed by characteristic respiratory symptoms, that is, wet rales, coughing and wheezing. Sick chickens crouch on the ground or on the perch. Each time the head and neck inhale forward, upward, open mouth, showing an effort to inhale posture, there is a wheezing cry. Severe cases, high dyspnea, spasmodic cough, can produce bloody mucus. If the secretion can not come out and block the trachea, it can suffocate to death. Diseased chickens lose appetite or disappear, lose weight quickly, the crown is purple, sometimes discharge green thin feces, and finally die of exhaustion, and the egg production of laying hens decreases or stops rapidly. The course of the disease is 5-10 days or longer, the undead often recover after 8-10 days, and some can become infected chickens.

When prevention and treatment occurs, it can be treated symptomatically, and antibiotics can be used to prevent secondary infection. Breeding and management equipment and chicken sheds should be disinfected. Sick chickens should not be raised in mixed herds with susceptible chickens. In the endemic areas of the disease, chickens can be immunized with attenuated vaccine. The time of the first immunization was about 4 weeks old, and the second immunization was carried out after 6 weeks.

[prescription 1]: 50-100000 units of streptomycin were injected. Usage: intramuscular injection twice a day for 3-5 days. When you have difficulty breathing, you can also inject 0.5-1 ml of 20% camphor water injection into the muscle at a time.

[prescription 2]: 20-40 grams of ribavirin. Usage: mix it with 100kg feed and feed it for 3-5 days.

[prescription 3]: 1 dose of attenuated vaccine to prevent infectious laryngotracheitis. Usage: 30-day-old eye drops, nasal drops. Note: as vaccination can make chickens carry virus, this prescription is only used in areas where the disease is endemic.