Diagnosis and Treatment Report of Chicken Feather Lice Disease

Feather lice are a common external parasitic disease in chickens. At a chicken farm in Taobei District, an outbreak of feather lice disease caused a significant drop in egg production and a decline in farming economic returns. The diagnosis and treatment results are reported as follows:

1 Occurrence of the disease

The chicken farm had five years@#@230@#@experience, bringing in chicks every spring of the previous year, going through one laying period, and culling them in the autumn of the following year, using an all-in-all-out system. In early December 2003, the egg production of 20,000 young laying hens kept in the farm's four chicken houses dropped significantly, along with feather loss. They had adjusted the calcium, phosphorus and multivitamin content in the feed, the light intensity, and added antibiotic drugs to the feed, but the treatment results were all poor.

2 Clinical symptoms

The flock often huddled together, was restless and uneasy, and showed signs of flock panic. The feathers were ruffled, mostly broken and bent. Most chickens pecked their own feathers. The chickens were emaciated, and red rashes and dander were visible on the skin where feathers had fallen out. On examining the chickens' bodies, large numbers of feather lice could be seen crawling on the sparsely feathered areas of the head, neck, back, abdomen and under the wings, as well as at the base of the main feathers, with dander, and feather lice were observed. Necropsy of several chickens revealed no pathological symptoms.

3 Diagnosis

Based on the chickens' extreme itching and restlessness and examination of the flock, large numbers of feather lice were found parasitizing the base of the skin feathers of the chickens' bodies, and it was confirmed as a mixed infection of chicken body lice, chicken head lice and chicken down lice.

4 Treatment

The chickens' bodies were sprayed with 12.5 g/L deltamethrin, and the chicken house equipment was disinfected. Spraying was carried out once each on the 4th day and the 10th day after the first spraying. One week after spraying, the health of the flock improved markedly and egg production gradually recovered. After 3 spray treatments, all feather lice died and egg production returned to normal levels.

5 Prevention

The flock was regularly sprayed and disinfected with insecticidal drugs, once every 2 months, and after that the disease never occurred on the farm again.

6 Summary

6.1 Feather lice are a common external parasitic disease of chickens and can occur in all four seasons. They feed on feathers and dander. The cause is infected chickens passing the infection to one another. The harm depends on the degree of infection in the chickens. Severely infected flocks can cause stunted growth in chicks and reduced egg production in adult chickens. Because the symptoms in affected chickens are not obvious and the losses are not easily seen, people often do not pay enough attention, so the disease is not brought under timely and effective control.

6.2 The clinical symptoms of this disease are easily misdiagnosed as incomplete feed nutrition, calcium deficiency and other trace elements, excessive light intensity, etc. When encountering suspected cases, the pathogen should be examined so as to confirm the diagnosis and treat it reasonably.

6.3 For the treatment of feather lice, the drug solution concentration must be properly controlled and used according to the instructions. After feeding and drinking, the feed and water should be cleaned up to prevent chickens from accidentally eating feed contaminated by the drug solution and suffering poisoning. When applying the drug, the chicken house temperature should be kept above 18°C to prevent the chickens from catching a cold after being wet from the spray.

6.4 The chicken house should be kept clean and sanitary, and regular disinfection work should be carried out. Killing insects and eliminating lice is one of the important factors in improving chicken production performance and increasing farming returns. It is recommended that chicken farmers pay attention to lice eradication work.