Because feline leukemia, or FeLV, causes a slow deterioration, possibly not noticeable until months or years after the initial infection, you may not catch it before the virus moves into secondary viremia. This is the second and more damaging stage of the virus. Have your cat tested if you notice slow consistent weight loss, pale or inflamed gums, deterioration of fur, chronic diarrhea, seizures, enlarged lymph nodes, anorexia, fever, eye problems, and reproductive problems.
Symptoms of the First Stage: Primary Viremia
Feline leukemia is tricky to spot because there are rarely symptoms associated with the first stage, primary viremia. This is because the virus is attacking the immune system itself. When the immune system is weak, the cat becomes susceptible to everything that attacks. Any kind of secondary infection can become perilous. Often the secondary infection is identified, but the root problem, the leukemia, is overlooked. It is extremely important to test for feline leukemia at any sign of sickness, regardless of previous test results.
Symptoms of the Second Stage: Secondary Viremia
The symptoms associated with secondary viremia, or the second stage of feline leukemia in which the bone marrow is infected with the virus, are chronic secondary bacterial, fungus, or viral infections, enlarged lymph nodes and lymphoma, chronic inflammation of tissue, primarily in the mouth, and persistent diarrhea. Look for chronic skin infections, urinary tract infections and/or upper respiratory infections. It is common that infected pregnant cats cannot bring a pregnancy to full term, often losing the babies early. Any reproductive failure can be an indicator of feline leukemia. Cats with feline leukemia may have a number of problems with their eyes, such as an extended third eyelid, and yellowing of the whites of the eyes.
Unfortunately, cancer may actually be a symptom of feline leukemia. While its name belies cancer to begin with, feline leukemia is not a cancer, but it can result in lymphoma or any other kind of cancer or tumor. Because feline leukemia suppresses the immune system to such a great degree, there’s no way to fight the cancer cells, which may otherwise be easily defeated. All of these symptoms are reasons to get your cat or cats tested for FeLV, possibly even more than once.
This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis or treatment by, your veterinarian with respect to your pet. It has, however, been verified by a licensed veterinarian for accuracy.
More on Common Symptoms of Illness in Cats:
Warning Signs Your Cat May Be Sick
What to Know About Your Pet’s Weight Gain