Avian Lymphomatosis Virus (ALV), also known as Avian Leukosis Virus, is a retrovirus that primarily affects birds, specifically poultry. It belongs to the family Retroviridae and is classified within the genus Alpharetrovirus. ALV is responsible for causing lymphomas or tumors, which are malignant cancerous growths affecting the lymphoid tissues, in chickens and other avian species.
The virus infects the white blood cells of the infected bird, targeting the lymphoid organs such as the bone marrow, liver, spleen, and bursa of Fabricius. Transmission of ALV occurs through horizontal routes, primarily through the ingestion of virus-contaminated feed and water, as well as vertical routes from infected hens to their offspring during the embryonic stage or through the eggs.
Symptoms of Avian Lymphomatosis Virus infection may vary and can include weight loss, decreased egg production, pale combs and wattles, anemia, increased susceptibility to secondary infections, swollen abdominal area due to enlarged organs, lameness, and tumors in various parts of the body. The disease progresses slowly, and affected birds may live for months or years without showing severe clinical signs.
Control and prevention measures for Avian Lymphomatosis Virus primarily focus on practicing strict biosecurity measures, such as disinfecting equipment, preventing contact with wild birds and rodents, using quality feed and water sources, and culling infected birds to prevent the spread of the virus. Additionally, vaccination programs have been developed to boost the immunity of susceptible chicken flocks against ALV.
