Feline Leukemia Infection in Kittens

Risks and Test Results Assessed in Light of Physical Health


Our two adorable kittens have been diagnosed with feline leukemia. We are concerned they will not survive their shots or spaying. Being that they are 5 months old, I’m worried that the female will get pregnant from her brother.  Is there a feline birth control pill or shot?  We love these kittens and have gone through so much with them.


Dr. Nichol:

I know what you mean about protecting those babies. Kittens seem so vulnerable. The good news is that feline leukemia infection alone will not increase the risks of surgery or vaccination but it can create other problems.


Feline leukemia virus (Felv) is potentially dangerous because it can make it hard for the immune system to fight disease. In some cats it’s fatal. It’s a contagious infection that starts in the lymph nodes and can ultimately lead to virus in the saliva and urine. Persistent infections usually develop 4-6 weeks after the initial exposure. Symptoms can start months to years later. Many cats eliminate the virus after they test positive. Others become permanently infected. A few develop malignant cancers.


Felv test results must be considered in light of a cat’s general health. If your kittens have chronic symptoms like coughing or sneezing, swollen lymph nodes, diarrhea, red gums, weight loss, skin disease or infected ears they may have an active Felv infection. But if they’re playful, eating well, and normal on physical exam they should do just fine with spaying and neutering.


Have a pre-anesthetic lab profile plus a repeat Felv test done on each kitten before surgery. If their organ function is good you can go ahead and have them sterilized. They should be retested for Felv 4-8 weeks later to determine whether the virus in their bodies is persistent or just transient.


If your kittens test positive I would avoid the stress of any vaccinations. I would also discourage contact with other cats unless and until they are free of Felv. There is a vaccine available for cats who test negative. It is not 100% protection but it may be important for individual high risk cats.


Regarding the birth control option, we actually had two drugs that were reliable but, after several years of use, neither was considered safe. There are no currently available contraceptives that I would recommend. In a practical sense, if your kitties are healthy enough for breeding they are probably in good enough shape for anesthesia and surgery. You are right to prevent a pregnancy.