Necrotizing enteritis

Necrotizing enteritis, also known as enterotoxemia, is an acute infectious disease caused by Clostridium welchii. The main manifestation is that the sick chickens discharge black or mixed with blood feces, and the dead chickens are characterized by necrosis of the mucosa of the posterior small intestine. The occurrence of this disease has obvious incentives, such as large flock density, poor ventilation; sudden change of feed and low protein content of feed; unreasonable frequent use of antibiotics, resulting in intestinal flora disorder, digestive function decline; coccidiosis is more likely to induce this disease. The disease occurs frequently in flat chickens, brood chickens and bred chickens. Broiler disease occurred mostly at 2~8 weeks of age. It can occur all year round, but it is prone to coccidiosis in the wet season. Because there are many factors inducing the disease, that is, caused by comprehensive factors, some people call the disease "enterotoxic syndrome", initially called the disease "enterotoxic syndrome", which can be seen in the technical promotion materials of a veterinary drug manufacturer in Shandong Province. The name of "enterotoxic syndrome" has been widely accepted by the people. Because of its diversified causes, it may be easier for grass-roots farmers or veterinarians to accept the name than "necrotic enteritis". However,"enterotoxic syndrome" this disease has not been named by the state authority veterinary department recognized, still can not be elegant. Clinical symptoms The disease often occurs suddenly, and sick chickens often die suddenly without obvious symptoms. A little longer course of disease can be seen depressed chicken spirit, feathers rough chaos, loss of appetite or waste must. Faeces are not neat, there are indigestible dregs (overfeed), so they are pale yellow, mixed with blood, you can see the detached intestinal mucosa, showing a broken shape, when mixed with blood, they look like earthworms. Under normal circumstances, the incidence and mortality of this disease is not high, such as timely treatment for 1 week that is to stop. However, if there is a viral disease or E. coli disease, the death rate increases significantly. After opening the abdominal cavity, you can smell the smell of rotting corpse that is rare in general diseases. The most characteristic changes occurred in the intestine, especially in the middle and posterior segments of the small intestine. The intestinal tract surface is dirty gray black or dirty black green, the intestinal cavity is dilated and inflated, which is 2~3 times that of normal intestinal tract, and the intestinal wall is thickened. Intestinal cavity contents are liquid, foamy, blood or dark green. Intestinal wall hyperemia, sometimes bleeding points, mucosal necrosis, was different in size, shape of bran-like necrosis focus, and some of the formation of pseudo-membrane, easy to peel off. Other organs were mostly congestion, no specific changes, there were reports of extensive degeneration and necrosis on the liver. Diagnosis According to epidemiological characteristics and pathological changes of characteristics can make a preliminary diagnosis. The diagnosis of this disease mainly depends on smear microscopy and isolation and identification of pathogenic bacteria. Fresh dead chickens can be taken intestinal mucosa scraping smear or liver contact, gram staining, microscope can see a large number of uniform gram positive short thick, obtuse round at both ends of the large bacteria, single scattered or paired arrangement, uniform staining, capsule. In the diagnosis, attention should be paid to the difference between excessive feeding phenomenon and ulcerative enteritis caused by problems with feed raw materials. The prevention measures are mainly to strengthen the feeding management, improve the disease resistance of chickens, take effective measures to reduce the impact of various stress factors, and do a good job in the prevention of other diseases. The occurrence of coccidiosis should be controlled in flat chickens, which is of great significance to prevent this disease, especially to control coccidiosis in flat chickens raised on ground bedding. It is worth noting that at the same time of treatment, it is very important to improve the sanitary conditions of chicken houses, reduce density, strengthen ventilation, and do a good job in feeding management.