Equine Infectious Anemia Virus (EIAV) is a viral disease that affects horses, donkeys, and mules. It is caused by a retrovirus and is primarily transmitted through blood-sucking insects, such as horseflies and deerflies. The virus can also spread through contaminated equipment or blood transfusions. Infected animals may show no symptoms, but some can develop fever, weakness, and swelling. There is no cure for EIAV, and affected animals must be isolated to prevent further transmission. Vaccines are not available, so prevention focuses on controlling insect populations and practicing good hygiene in stables.