This week in our clinic we have diagnosed Feline Immunodeficiency Virus (FIV) in two cats from the same household. The first cat was brought to see us because of a vague illness characterised by lethargy, a reduced appetite and intermittent vomiting. When it was examined we discovered mouth ulcers and a high temperature. A blood test soon revealed the cat to be positive for FIV. The other cats in the house were tested; one was positive, the other, luckily, negative.

FIV is a virus that infects only cats. It acts on the body in much the same way as HIV affects humans, causing a weakened immune system. This increases the susceptibility to infections such as cat flu and other more serious diseases. The incubation period of the virus is long, and cats commonly show no signs of infection for many months or years. Gradually, as the immune system is overcome, various illnesses become apparent. There is no vaccination against FIV, nor is there any cure.

The virus is spread from cat to cat, most commonly through cat bites as saliva and blood contain virus. There is also some small risk that infection can be passed through sharing food bowls and mutual grooming.

As the infection develops more persistent signs appear, commonly vomiting, recurrent infections, inflamed gums (gingivitis), mouth ulcers and anaemia. It is a simple and reliable blood test that your vet can do to test for FIV.

If your cat is positive for FIV, it is important to keep it indoors to prevent it spreading the virus to other cats. Ideally, keep it isolated from other cats completely. The cat will need regular vet checks to monitor for signs of disease. Whilst the disease is not curable, there are drugs that can be very helpful to alleviate the illness and keep infection at bay. It is also important to have in-contact cats' blood tested. You should also make sure affected cats and in-contact cats are kept up to date with booster vaccinations against other feline diseases.