Diagnosis and treatment of campylobacter disease in chickens

Chicken campylobacter disease, also known as chicken vibrio hepatitis, is an infectious disease of young or adult chickens caused by campylobacter infection. The disease is characterized by liver hemorrhagic necrotizing hepatitis with fat infiltration, high morbidity, low mortality and often chronic process. Campylobacter is an important food poisoning bacteria, which can cause fever, vomiting, diarrhea and other symptoms. Therefore, it is listed as one of the key quarantine items of meat health and quarantine.

I. pathogen

The pathogen of this disease is a gram-negative, mobile, slightly aerophilic campylobacter. The bacteria can grow in broth containing serum or on beef extract Agar medium in 10% carbon dioxide environment to form small, round, moist, colorless and transparent colonies. It does not dissolve blood on blood medium. Can produce hydrogen sulfide, do not ferment mannitol and xylose, do not produce indigo matrix.

Campylobacter is extremely sensitive to drying, which can be killed quickly by drying and sunlight. The bacteria survived less than 2 hours in 20 ℃, 4 weeks in 4 ℃ water, 10 days in split chickens preserved in-9 ℃ and-12 ℃, and still could be detected after 182 days in-20 ℃ storage.

The strain is sensitive to various disinfectants, including 5% sodium perchlorate diluent (200000), 0.5% formalin solution, 0.15% organic phenol, 50000 quaternary amine compound and 0.125% glutaraldehyde.

II. Popular characteristics

The disease only infects chickens and turkeys under natural conditions, and it is more common in hens that have been born for the first time or have been in production for several months, and occasionally in chicks. The main route of infection is the digestive tract. The pathogens were excreted with feces, contaminated feed, drinking water and utensils, and were infected by healthy chickens after feeding. Most of them are sporadic or endemic. The incidence of the disease is high, and the mortality rate is 2%, 5%.

III. Clinical symptoms

The disease is mostly chronic, diseased chickens show lethargy, weight loss, crown wrinkle and often have diarrhea, yellow feces. The progress of the disease is slow, but there are also very fat chickens who die acutely and are still laying eggs within 48-72 hours before death. The flock could not reach the expected egg production peak, and the laying rate decreased by 25%, 35%. The development of the chicks was blocked, the abdominal circumference increased, and anemia and anthrax appeared.

IV. Pathological changes

The most obvious lesion of this disease is in the liver. The acute cases showed hepatic parenchyma degeneration, swelling and crispness, with hemorrhagic area, hematoma and necrosis under the liver capsule. The surface of the liver is mottled by many bleeding spots. There are a large number of stellate necrotic foci scattered on the surface and parenchyma of the liver, or covered with cauliflower-like necrotic areas. the liver is yellowish brown and the gallbladder is full of mucous secretions. Death from acute internal hemorrhage is often caused by liver rupture. Chronic cases showed cirrhosis, atrophy and ascites; splenomegaly, occasionally yellow fragile infarcted area; ovarian follicle atrophy and degeneration, only the size of pea.

5. Diagnosis

A preliminary diagnosis can be made according to epidemic characteristics, clinical symptoms and pathological changes, and laboratory examination should be carried out for diagnosis.

VI. Prevention and control measures

Prevention is mainly through strengthening feed management, strict disinfection, reducing stress and other comprehensive measures, and drug prevention can also be added to feed. Streptomycin can be used for diseased chickens, each 50,000 international units, intramuscular injection, twice a day. It can also be mixed with tetracycline or oxytetracycline, adding 2 grams per kilogram of feed for 3-5 days.