Avian Leukosis Viruses (ALVs) are a group of retroviruses that primarily affect birds, particularly chickens, causing a range of diseases collectively known as avian leukosis. They belong to the family Retroviridae and subfamily Orthoretrovirinae. ALVs are characterized by their ability to induce malignant tumor formation in various organs, including the liver, spleen, kidneys, and bones, and they can also affect the reproductive and immune systems of infected birds.
ALVs are transmitted horizontally through contact with infected birds or vertically through the egg. Infection can occur at any age but is most commonly seen in young birds. Infected birds may exhibit various symptoms, such as decreased appetite, weight loss, weakness, increased thirst, pale comb and wattles, anemia, and increased susceptibility to other infections. Mortality rates can vary depending on the strain and age of the bird, as well as concurrent infections.
Prevention and control of ALVs largely rely on strict biosecurity measures, including proper disinfection, isolation of infected birds, and restriction of movement. Vaccination is also available for some strains of ALVs and can be an effective preventive measure.
The importance of managing ALVs in poultry production is crucial to prevent economic losses and maintain animal welfare. Research and ongoing surveillance are key to understanding the epidemiology, pathogenesis, and genetic diversity of ALVs, which can aid in the development of more effective control measures.
