Acute feline leukemia virus infection causes altered energy balance and growth inhibition in weanling cats

The process of severe weight loss caused by the feline leukemia virus (FeLV) in cats may begin before an immune response to the virus is seen in blood. Researchers inoculated eight of 16 newly-weaned cats with FeLV. The other eight became the control group. Cats exposed to FeLV took in less food and were less active than control cats. FeLV-infected cats lost 15% of their body weight compared with control group cats. Their growth rate was also lower. The progression of FeLV infection is similar to that of HIV infection. Both cause nausea, fatigue, and loss of appetite even before the antibodies against the virus appear in the blood. Appropriate nutritional therapies should be given to people or animals with known retroviral infection before the disease has a chance to progress.