Side Effects of Leukemia in Cats

Feline leukemia is a viral disease that can manifest itself in many ways, presenting many different symptoms. According to Dr. James W. Day, more than 50 percent of cats that are infected with the FeLV virus will show symptoms, and as many as 80 percent will die from a related disease. There are many different side effects, or other diseases, that arise from FeLV infection.

  1. Immune System Side Effects

    • Feline leukemia affects the cat's immune system, increasing the cat's susceptibility to secondary bacterial, fungal and viral infections. Many affected cats will have recurring infections of the mouth, the skin and the respiratory system. Because the immune system is compromised, infections that the body would normally fight off can become fatal in leukemia-positive cats.

    Reproductive System Side Effects

    • Kittens born to FeLV positive queens can suffer from fading kitten syndrome.

      Many cats with feline leukemia can suffer reproductive side effects like infertility, spontaneous abortions or stillborn kittens. Kittens that are born to FeLV-positive cats may suffer from fading kitten syndrome--these kittens are weak, have poor appetites, have no energy, and eventually just "fade away" and die.

    Gastrointestinal Side Effects

    • FeLV-positive cats often experience gastrointestinal side effects like decreased appetite, vomiting, diarrhea and weight loss. They can develop cancers of the stomach and intestine.

    Neurologic Side Effects

    • FeLV-positive cats can have neurologic side effects like lameness, seizures, paralysis, blindness, changes in behavior and loss of balance.

    Circulatory Side Effects

    • Feline leukemia affects the cat's bone marrow, so FeLV-positive cats often become anemic--having decreased numbers of red blood cells. Owners will notice pale mucous membranes, especially the cat's gums. FeLV can also cause decreased numbers of platelets, and/or abnormal platelets in the blood. These cats may have bleeding disorders and owners might notice excessive bruising on their cat's skin. Levels of calcium and protein in the blood can be elevated, stressing internal organs like liver and kidneys.

    General Side Effects

    • Cats with feline leukemia will show some general side effects. Their lymph nodes may be enlarged. They may seem to just lose interest in life, not grooming themselves, becoming lethargic, hiding, drinking more water and urinating more. Owners may describe their cats as "just not doing well."