Prevention and treatment of Avian Infectious bronchitis

Infectious bronchitis is an acute and highly contagious respiratory infectious disease of chickens caused by infectious bronchitis virus, characterized by dyspnea, rales, coughing, breathing with open mouth, and sneezing. If the pathogen is not a nephropathic strain or does not occur with disease, the mortality rate is generally very low. Let's take a look at the symptoms and prevention of infectious bronchitis.

Popular characteristics

There was no significant difference in chicken breeds infected with infectious bronchitis, and chickens of all ages were susceptible, but the symptoms were more obvious in chickens within 5 weeks of age, and the mortality rate was up to 150.19%. The onset season is mostly from the end of autumn to the end of spring of the following year, but it is the most serious in winter. The main environmental factors are cold, heat, crowding and poor ventilation, especially strong stress such as vaccination, group conversion and so on. The mode of transmission is mainly through the air, in addition, personnel, appliances and feed are also media. The disease spreads rapidly and often affects the whole population within 1-2 days. it is generally believed that the disease can not be transmitted vertically through breeding eggs.

Develop symptoms

1. Chicken symptoms: there were no prodromal symptoms and the whole group had a sudden onset almost at the same time. Initially show respiratory symptoms, runny nose, tears, swollen nose, coughing, sneezing, neck opening and gasping for breath. An obvious hoarse cry was heard at night. With the development of the disease, the symptoms aggravated, shrinking head and eyes, hanging wings, loss of appetite, increased appetite, such as untimely treatment, there are individual deaths.

2. Laying hens: mild dyspnea, cough, tracheal rales and "snoring". Low spirits, diet, pull yellow thin feces, the symptoms are not very serious, there are very few deaths. The egg production began to decrease on the second day of the disease, and decreased to the lowest point in 1-2 weeks. sometimes the laying rate could be reduced to half, soft and deformed eggs were laid, the egg white became thinner, the egg white was separated from the yolk, and the hatching rate of breeding eggs also decreased.

3. Nephrotic variant: most of them occurred in 20-50-day-old chicks. When infected with infectious bronchitis strain of nephrotic variant, diseased chickens can not only have respiratory symptoms, but also cause nephritis and enteritis due to the damage of renal function. The symptoms of renal bronchitis are biphasic, with respiratory symptoms for a few days in the first stage, followed by a "recovery" phase in which the symptoms disappear, and the second stage begins to drain white or green faeces and contain large amounts of urate. Diseased chickens lose water, show weakness and drowsiness, and their crowns fade or appear purple.

Prevention and cure method

1. Prevention: prevention should consider reducing inducing factors and improving the immunity of chickens. After cleaning and disinfecting the chicken house, introduce the chicken seedlings from the chicken farm without infectious bronchitis, do a good job in the feeding and management of the chicks, pay attention to ventilation and ventilation, prevent overcrowding, pay attention to heat preservation, and properly supplement the vitamins and minerals in the chicken diet. develop a reasonable immune program.

2. Immunity: vaccination is a main measure to prevent infectious bronchitis at present. at present, there are many kinds of vaccines used to prevent infectious bronchitis, which can be divided into inactivated vaccine and attenuated vaccine.

① inactivated vaccine: the preparation of inactivated vaccine from locally isolated virus strains is a very effective method, but it has not been widely used because of the limitation of production conditions.

② attenuated vaccine: at present, H120 and H52 strains from Holland are widely used in monovalent attenuated vaccine. H120 is safe and effective for 14-day-old chicks, with a protection rate of 90% after 3 weeks of immunization. H52 can cause serious reaction to chickens under 14 days old, so it is not suitable to use, but it is safe for chickens aged 90-120 days, so the commonly used procedure is H120 at 10 days old and H52 at 30-45 days old.

3. Treatment: there is no effective treatment for infectious bronchitis at present, and people often use the symptomatic therapy of combination of traditional Chinese and western medicine. As chicken flocks are often complicated with bacterial diseases in actual production, the use of some antimicrobials is sometimes effective. For chickens with nephrotic variant infectious bronchitis, some people use oral rehydration salts, 0.5% sodium bicarbonate, vitamin C and other drugs can play a certain effect.

When ① occurs, you can use Longda tripeptide to inject 1000 adult birds and 2000 chicks per set, usually once. Drinking water each set of 500 adult birds, 1000 birds concentrated 3-4 hours to drink, generally drink once, seriously ill drinking water two days, once a day. Antimicrobials were 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.

② Kechuankang boiling water for half an hour and then add 20 kilograms of cold boiled water as drinking water for 5 days. At the same time, 50 grams of morpholine guanidine hydrochloride powder is added to every 25 kg feed or 50 kg water, the effect is better. Each gram of doxycycline powder with water of 10 kilograms and 20 kilograms is allowed to drink for 3 days.

Good results can be obtained when ③ is mixed with 1.5g per kilogram of feed and 30g of Banlangen granule, and the chicks are fed freely. A few seriously sick chickens are raised alone, supplemented with a small amount of Sydney syrup for 3 days. Kechuanmin, Archie Chuan Ding and so on have special effects.