Tuesday's Tips from our Doctors- Feline Leukemia (FeLV) !!

Tuesday's Tips from our Doctors! 

Recently our  Doctors asked how they could share some facts about the common (and not so common) things that can effect the health of our  pets in S. Florida.  This is what we can up with. Be on the look out for more Tips from our Doctors and be sure to let us know what other things you would like to know about!

FeLV stands for Feline Leukemia Virus. It is a retroviral disease of cats that affects their bone marrow and immune system. It is estimated that about 3% of cats worldwide are affected with this virus. FeLV can be transmitted multiple ways; it is shed in the saliva, feces, milk, and urine of an infected cat, although the primary route of transmission is through saliva.  

Transmission can occur via grooming, licking, biting, as well as sharing dishes and litter pans. Therefore, close cat-to-cat contact is required for transmission. Transmission from infected mother to kitten may occur during pregnancy, and it can also be transmitted by the exchange of blood. 

Any age a cat can become infected with the virus. However, kittens and younger cats are at the highest risk of significant and rapid progression of the disease because of their naïve immune system. Some cats will contract the disease and will not show clinical signs (signs of illness), but they will continue to spread the virus. These are known as latent carriers. They can become symptomatically ill when stressed. On rare occasions, some cats that are infected may eliminate the virus on their own and never become ill. These cats become immune.

 

There is no specific treatment or cure for a FeLV infection. Many cats with FeLV will live normal lives, but their life span tends to be significantly shorter. Most cats will not live more than 3 years past the time they are infected with the virus.  Many cats become sick with lymphoma (cancer), bone marrow disease (such as leukemia), or feline infectious peritonitis (FIP).

FeLV cats may encounter other problems that include an earlier onset of dental disease and more upper respiratory infections (colds), as well as multiple diseases related to being immune suppressed. If your cat becomes ill and is FeLV positive, treatment involves supportive care based on their clinical signs. Examples include supportive care for the leukemia form (bone marrow disease). The lymphoma form of the disease may be treated with better results using chemotherapy drugs, but is still not curable. 

There is a vaccine available for the prevention of FeLV. This vaccine is considered a “core” vaccine for kittens. This means all kittens should receive the vaccines as the proper standard of care in veterinary medicine. 

Kittens will receive 2 vaccines 2 weeks apart (at 12-14 weeks of age, and then again at 15-17 weeks of age), and then a booster one year later. Current recommendations in the literature indicate that after 2 years of age (with proper vaccination until then), yearly vaccination is “risk based.” This means certain cats should continue to receive the yearly vaccine. This includes cats who have certain factors which increase their risk of exposure such as going outdoors, living in large colonies, or living with positive cats. 

All cats should be tested for FeLV before being vaccinated. New kittens can be tested as early as 6-8 weeks of age. Your veterinarian has an ELISA test (this is normally able to be done in the office with a few drops of blood) which screens for FeLV and FIV (another virus of cats). If you know your cat has been exposed to FeLV, it is recommended to test them again at least 30 days post exposure to ensure a second negative result. Some cats will test positive, but then clear the virus on their own and test negative the second time.  

Kittens should be tested at an early age (at adoption, etc.) however they should be re-tested at least 30 days later to ensure a second negative result since the virus may take weeks to months to be detected. If your cat tests positive, a confirmation test (known as an IFA (immunoflourescent assay test) can be done at an outside laboratory to confirm the positive result. 

 If your home has a FeLV positive cat, it is recommended that you do not bring any new negative status cats into the household to minimize other cats from being exposed. If you own two cats, separating them to avoid possible bodily fluid exchange is best. Luckily, the virus is very unstable in the environment, and common household cleaners easily destroy it. Even without cleaning, the virus is destroyed naturally in a span of days. 

Angela Suarez, D.V.M. 

University of Florida, 2015