Feline leukemia virus (FeLV) is a retrovirus that infects cats. FeLV can be transmitted from infected cats when the transfer of saliva or nasal secretions is involved. If not defeated by the animal’s immune system, the virus can cause diseases which can be lethal.
The signs and symptoms of infection with feline leukemia virus are quite varied and include loss of appetite, poor coat condition, anisocoria (uneven pupils), infections of the skin, bladder, and respiratory tract, oral disease, seizures, lymphadenopathy (swollen lymph nodes), skin lesions, fatigue, fever, weight loss, stomatitis, gingivitis, litter box avoidance, pancytopenia, recurring bacterial and viral illnesses, anemia, diarrhea and jaundice.
Asymptomatic carriers will show no signs of disease, often for many felines.