How to prevent cholera in poultry

Avian cholera is also called avian pasteurellosis or avian hemorrhagic septicemia. Pasteurella multocida is a virulent infectious disease. It is characterized by rapid spread, the most acute death of sick birds, coronary fat bleeding and liver necrosis. (1) Epidemic characteristics All kinds of poultry and wild birds can be infected with the disease, and chickens and ducks are the most susceptible. The susceptibility of geese is relatively low. The disease is often sporadic or endemic, and can occur all year round, but it is more common in autumn and winter. The main sources of infection of the disease are sick birds and infected birds. Bacteria pollute the environment through secretions and feces, and contaminated feed, drinking water and tools are important media. Infected cats, mice, pigs and wild birds break into poultry houses, which can also cause poultry to get sick. Its infection route is mainly digestive tract and respiratory tract, and it can also be infected through broken skin. (2) Clinical symptoms The incubation period of this disease is 1~9 days, and the earliest onset can lead to death within a few hours. According to the course of disease, it can be divided into the most acute type, acute type and chronic type. 1) The most acute type is common in the early stage of the epidemic, especially in strong and high-yield chickens and ducks, with almost no obvious symptoms, sudden uneasiness, convulsions, ground struggle, flapping wings and rapid death. Some chickens behaved normally the night before and were found dead in the shed the next morning, and some even died suddenly when laying eggs. 2) Acute cases are the most common, and appear with the development of the epidemic. Sick birds are listless, their feathers are loose, their wings droop, their eyes close and their necks shrink, and they are sleepy. The body humidity rises to 43~44C. Many sticky secretions often flow out of the mouth and nose, and the crown and glow are blue-purple. Dyspnea, shortness of breath. Severe diarrhea often occurs, and the stool is green or grayish white. Loss of appetite or disappearance, increased appetite. Course of disease 1~3 days, and finally died of failure, coma, etc. 3) Chronic type is mostly transformed from acute cases and generally appears in the late epidemic period. One or both sides of the sick chicken have swollen flesh, swollen joints, pus discharge and limping. Some cases have respiratory symptoms, swollen sinuses and mucus. Accumulation of secretions in the throat, unpleasant smell and difficulty breathing. The course of the disease can be extended to weeks or months. Some people died of persistent diarrhea, others recovered, but their growth was blocked, and even they could not lay eggs for a long time, which became the carrier of spreading pathogens. (3) Pathological changes 1) In the most acute type, there was no obvious lesion, only a bleeding point the size of a needle tip was found in the coronary sulcus of the heart, and a small necrotic focus was found on the surface of the liver. 2) Acute serous hemorrhage. The coronary sulcus of the heart is densely covered with bleeding points, as if it were spraying wine. Pericardial thickening, pericardial fluid increased turbidity. Pulmonary congestion and bleeding. Hepatomegaly, brain changes, brown or brownish yellow, characteristic grayish yellow or white necrotic focus, large needle tip or millet color. Dirty cards generally have no obvious changes. Severe bleeding of musculoskeletal and duodenal mucosa, catarrhal or hemorrhagic enteritis in the whole intestine, and blood mixed with intestinal contents. 3) The poultry with chronic diseases are emaciated and anaemic. When respiratory symptoms appear, there is a lot of mucus in the nasal cavity and paranasal sinuses. Sometimes there is a large yellow-white dry and cool necrotic focus in the lungs. In some cases, there is exudate and caseous necrosis around the joint capsule and joint, and some cases can see edema of cockscomb, meat or earlobe, which can further necrosis. (4) Preventive measures ① Strengthen the feeding management of poultry: reduce the influence of stress factors, do a good job of cleaning and disinfection, and improve the disease resistance of poultry. ② Strictly prevent the introduction of sick birds and cured infected birds: the imported birds should be kept in isolation. If they live in groups, they should be isolated 1 week and take oxytetracycline for 3-5 days. After breeding, the whole flock of poultry should take oxytetracycline for 2~3 days. ③ Vaccination: Vaccination can be carried out regularly in epidemic areas. Commonly used vaccines for avian cholera include attenuated live vaccine and inactivated vaccine, such as attenuated vaccine of avian cholera 73 1, inactivated vaccine of avian cholera 833, attenuated vaccine of avian cholera Gha E and inactivated vaccine of avian cholera emulsion. ① Drug prevention: If poultry cholera occurs nearby. When the poultry in this farm are threatened, we can use live forest (3-4g/kg feed) or ethanol (0.3g/kg feed) and so on. , once every 1 week for 1-2 days until the epidemic subsides. Chickens are easily infected with avian cholera before delivery or during the peak laying period, which is in late autumn and early winter, and the weather is changeable or cloudy. Oxytetracycline can be used for 2~3 days (per kilogram of feed 1.5 ~ 2g), and can be used again at intervals of 10~ 15 days if necessary, which also has preventive effect on other fine chrysanthemum diseases. (5) Treatment: ① add 0.5%~ 1% sulfadiazine powder to the feed for 3~4 days, stop taking the medicine for 2 days, and take the medicine for 3~4 days: you can also add 1 g medicine to every 1 000 ml of drinking water for 3~4 days; ② Adding 0.65444 into the feed. ③ Tons of ethanol, 30 mg per kilogram of body weight, once a day/kloc-0, for 3~5 consecutive days. Laying hens, ducks and broilers whose withdrawal period is less than 2 1 day should not be selected. (4) intramuscular injection of penicillin, with a weight of 40,000-80,000 units per kilogram, once in the morning and once in the evening. Chickens and ducks with serious illness can be given. ⑤ intramuscular injection of ciprofloxacin, ofloxacin or sarafloxacin at the ratio of 5~ 10 mg/kg body weight, twice a day; Drinking water at the ratio of 50~- 100 mg/kg body weight for 3~4 days.