What are the prevention and treatment methods for avian spirochetosis?

Spirochetosis is an acute febrile, septicemic infectious disease of geese and other poultry and wild birds caused by Borrelia anserina. Its main clinical and pathological features are fever, diarrhea, enlargement of the liver and spleen, and necrosis. The disease has a high mortality rate, and after affected birds develop the disease it causes mass deaths.

Spirochetosis occurs in various parts of the world, but is most common in free-range poultry in tropical and subtropical regions.

1. Pathogen and epidemiological characteristics.

Sick birds, dead birds and their excreta are the main sources of infection of this disease. Susceptible birds coming into contact with sick or dead birds and their excreta are often easily infected, and the disease can also be transmitted through the bites of arthropods, mosquitoes and poultry mites, but the main vector of this disease is Argas persicus. When poultry are naturally infected with the disease, transmission is often caused by tick bites.

This disease can occur throughout the year, but is most common in warm, humid seasons.

2. Clinical symptoms.

The incubation period of natural infection is 3-12 days, and the mortality rate is 33%-77%. Affected poultry show obvious clinical symptoms: poor spirits, a drooping neck and wings, ruffled feathers, fever, elevated body temperature, complete loss of appetite, drowsiness and thirst, diarrhea, passing large amounts of green feces or loose feces accompanied by white urates, and rapid emaciation, anemia, marked weight loss, nerve paralysis, and paralysis, finally dying from coma and exhaustion, with a disease course of 4-5 days. Very few affected birds can survive it and slowly recover.

3. Prevention and treatment measures.

To eliminate the intermediate host and transmission vector - Argas persicus, as well as mosquitoes and poultry mites - dipping in 0.5% malathion is commonly used to control tick larvae. A 25-50 mg/L solution of deltamethrin can also be sprayed or applied by brushing, or pyrethroid insecticide powders can be applied to the body surface and feathers; all of these can kill ticks on the body surface of poultry. In epidemic areas, avoid introducing tick-infested poultry into healthy flocks. For affected poultry, antibiotics to which this disease is sensitive, such as penicillin, kanamycin, tylosin and others, all have relatively good therapeutic effects. Abroad, researchers have already tried an inactivated spirochete vaccine, and immunizing poultry at 8-10 weeks of age also has a certain preventive effect.