Feline Leukaemia Virus (FeLV)


Feline Leukaemia Virus (FeLV) is a virus that attacks the immune system causing damage to the white blood cells, this makes the infected cat vulnerable to other infections, diseases, anaemia and cancers such as lymphoma and leukaemia.

This virus spreads through direct contact with the bodily fluids or faeces of infected cats, through grooming or sharing litter trays, feeding bowls, through mating behaviour or fighting (bite wounds). FeLV is most common among young, unvaccinated, un-neutered, outdoor cats. Mother cats can also transmit the virus to their kittens while they are in the womb and through their milk, although many kittens die or are aborted before birth. There is a long incubation period of months, or even years, before symptoms show in those that are infected. In the early stages, symptoms often go unnoticed because they are extremely diverse or very mild. As the infection progresses, symptoms become more severe.

Symptoms include:

  • Low energy (lethargy)
  • Poor appetite
  • Weight loss
  • Diarrhoea
  • Vomiting
  • Skin problems
  • Fever (high temperature)
  • Pale gums and eyes (anaemia)
  • Sore/ulcerated gums
  • Respiratory problems
  • Enlarged lymph glands
  • Many of these symptoms are common in numerous different conditions so please seek veterinary advice.

If you suspect your cat has FeLV, please speak to your vet, a blood test can be performed to detect the virus.

Unfortunately, there is no cure or reliable treatment for FeLV infection, and management is largely aimed at the treatment of secondary infections and supportive therapy to keep infected cats well for as long as possible.

Some positive cats can live without any major concerns for years with veterinary care and a maintained lifestyle and still have a good quality of life. It is important to keep infected cats strictly indoors to prevent spread of the FeLV virus to other cats and to reduce the exposure to other infections or diseases.

Sadly, many cats with FeLV ultimately become so poorly that they need to be put to sleep to prevent suffering.

Vaccination is important to protect your cat against this virus, FeLV is much better prevented than treated. The FeLV vaccination is considered a "core" vaccine and is recommended for all domestic cats.