Symptoms, prevention and treatment of streptococcosis in chickens

Chicken streptococcosis is an acute septic or chronic infectious disease of chickens. Both chicks and adult chickens can be infected, mostly showing local epidemics, characterized by lethargy, persistent dysentery, claudication and paralysis, or neurological symptoms. China's chickens, ducks, geese, pigeons have reported the disease, resulting in a considerable number of sick poultry death, resulting in greater economic losses, the following will introduce the symptoms and prevention and treatment of chicken streptococcosis.

I. symptoms of streptococcosis in chickens

1. Acute type: characterized by septicemia. Sudden onset, sickness, lethargy or lethargy, loss of appetite or loss of appetite, loose and dull feathers, purple or pale crown and beard, and sometimes swollen beard. Diseased chickens have diarrhea and discharge light yellow or grayish green dung. The egg laying of adult birds drops or stops. The acute course of disease ranged from 1 to 5 days.

2. Chronic type: slow course of disease, poor spirit of sick birds, loss of appetite, lethargy, heavy lethargy, like squatting, head hidden under wings or back feathers. Weight loss, weight loss, lameness, head tremor, or back, mouth upside down, some sick chickens with paralysis in their legs, unable to stand up. Some sick chickens develop ophthalmitis and keratitis. Eye conjunctiva inflammation, swelling, tears, fibrin inflammation, covered with a fibrin film. Severe cases can cause blindness.

2. autopsy characteristics of streptococcosis in chickens

1. Acute: subcutaneous and serous muscle edema, fibrinous pericarditis, yolk peritonitis, catarrhal enteritis. The liver, spleen and kidney were enlarged with bleeding spots and necrosis. Pulmonary congestion or edema. The airbag is turbid and thickened.

2. Chronic: fibrinous pericarditis, pericarditis. Parenchymal organs (myocardium, liver, spleen) have inflammation, degeneration or infarction. There are leg vaginitis, fibrinous arthritis, salpingitis and yolk peritonitis. The diseased birds are highly emaciated and abscesses are formed between the mandibles.

3. Nestling: malabsorption of yolk, soft, yellowish-brown liver mass, enlarged gallbladder, cecal tonsillar hemorrhage, fibrinous pericarditis and meningeal congestion and hemorrhage.

III. Prevention and treatment of streptococcosis in chickens

1. Prevention: in prevention, it is mainly to strengthen feeding management, reduce all stress factors, enhance the immunity of chickens, strengthen the management of sanitary disinfection, and disinfect the incubator with formaldehyde, which can greatly reduce the occurrence of streptococcosis.

2. Treatment: penicillin, gentamicin, tetracycline, oxytetracycline and other drugs can be used to treat acute and subacute infected chickens. Enrofloxacin is reported to be effective in the treatment of streptococcosis. Because Streptococcus can also develop drug resistance, it is best to combine the results of drug sensitivity test when using drugs.

IV. Differentiation of Streptococcosis in chickens

1. Colibacillosis: diversity of symptoms and lesions (chicken encephalitis, yolk peritonitis, pneumocystitis, arthritis, ophthalmitis, Escherichia coli granuloma, septicemia, etc.). Microscopic examination showed gram-negative, non-spores, microbacilli with systemic flagella and blunt circles at both ends.

2. Avian paratyphoid: the drinking water of diseased chickens increases, white water sample feces are discharged, and they are afraid of cold and like near the source of heat. Autopsy showed striped hemorrhagic spots or needle-sized necrotic foci in the liver, spleen and kidney, hemorrhagic inflammation of the small intestine, and Gram-negative slender bacilli at both ends.

3. Staphylococcosis: obvious traumatic infection, lameness (tarsometatarsal arthritis), a large amount of purplish black blood sample exudate or purplish red jelly under the chest and abdomen ("big navel"). Microscopic examination showed grape string accumulation of Gram-positive cocci.

4. Avian cholera: the diseased chicken crown and meat beard were dark purple, coronal fat and epicardial hemorrhage were found on the autopsy, and there were a large amount of gray-white small necrotic spots on the surface of the liver. Microscopic examination showed gram-negative, bipolar colored round microbacilli.