Feline Leukemia Virus -- FeLV 

If you're a cat owner, or know anything about cats, you will most likely have heard of "Feline Leukaemia Virus." Most infections are congenital, coming from the infected mother cat "in utero," or from drinking her milk, being licked by her, etc. The second most common means of transmission is through outdoor exposure to other cats.

In the US, approximately 2-3% of cats are infected with FeLV , a viral disease which attacks the immune system of the cat and leaves her vulnerable to a range of other infections. Much like HIV, FeLV is a retrovirus : a virus which produces an enzyme (reverse transcriptase) which allows it to insert copies of its own genetic material into the genetic profile of the cells they are infecting. As such, FeLV is a primarily a worrisome disease for outdoor cat owners.

Feline Leukemia Virus
Mutual grooming can pass infection*

How is FeLV spread?

Cats who carry FeLV, shed the virus in large quantities through their bodily secretions. The virus is present in saliva, nasal secretions, urine, feces and the milk of infected cats. When cats interact in any way, including mutual grooming, sharing food bowls, shared litter boxes or by scratching and biting one another, they risk spreading the virus. Infected mothers can also pass the disease to her kittens via the placenta or through nursing. It is important to note the virus cannot live outside the body.

How does FeLV affect a cat?

Feline leukaemia virus can cause a number of issues in a cat, ultimately the disease compromises the immune system, leaving the cat vulnerable to a wide variety of infections. It can cause cancerous growths, blood disorders and death. It is very important to test cats for FeLV in order to prevent the disease from spreading. Effective prevention methods include: keeping positive and negative cats separated and vaccinating negative cats who have been exposed to cats who are positive.

Signs of FeLV in Cats

In the early stages of the infection, the cat may not exhibit any symptoms as it can remain in-active or dormant for years. However, when the disease progresses, it is common for cats with FeLV to experience increasing periods of illness followed by brief remissions. Signs that may be seen in a cat with FeLV include:

  • Weight loss and loss of appetite
  • Enlarged lymph nodes
  • Inflammation of gums and mouth including bleeding in the gums
  • Pale mucus membranes
  • Ongoing fever
  • Infections throughout the body
  • Eye problems including conjunctivitis and vision issues
  • Changes in behavior including circling, seizures or restlessness

If you suspect your cat has FeLV, consult your veterinarian immediately. Tests can confirm whether the cat has it or is a carrier. Currently, there is no known cure, only the aggressive management of symptoms. If your cat is diagnosed with FeLV and shares your house with other felines, they must all be tested.

How do I Prevent my Cat from becoming Infected with FeLV?

The only way to prevent your cat from contracting FeLV is to keep her away from other cats. We also recommend:

  • If your cat is FeLV free, consider vaccination if your cat comes into contact with other cats whose status is either unknown or positive . Your veterinarian will be able to discuss vaccination protocols and the benefits. While vaccination does not guarantee your cat cannot become infected, it does dramatically reduce the risk
  • Spay/Neuter all cats: This will prevent them straying and reduce the risk of coming into contact with infected cats.
  • If you have an infected cat in the house, provide separate living areas, feeding bowls and litter boxes
  • If you have an unneutered cat, it is best to keep them indoors to prevent them coming into contact with infected cats and breeding with them.

FeLV is a common enough condition in cats to be cause for serious concern. With vaccination and careful management, you can reduce the chances of your cat becoming infected.

*Image courtesy of Dollar Photo Club