FeLV and FIV

Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) can cause many types of illness as well as death in infected cats. These viruses do not infect humans or other animals.
Feline immunodeficiency virus is more commonly found in male cats that are not neutered and in cats that fight with other cats. It is found less often in kittens and neutered adult cats.

The virus is spread through the saliva and is usually passed to other cats by bite wounds. In North America, about 3 to 5% of tested cats are found to be infected with FIV. In Latin America, up to 25% of tested cats are found to be infected.

Feline leukemia virus infection is more commonly spread among cats that live together. The virus can also be spread from mother to kittens, and among cats that fight. It is mainly spread through saliva when cats groom each other, and when food and water bowls are shared. In North America, about 4% of tested cats are found to be infected with FeLV. In Latin America, up to 42% of tested cats are found to be infected.

A cat newly infected with FIV may show mild illness, with fever or a drop in appetite. These changes do not last more than a day or two before the cat is back to normal. After the early days of infection, the cat may not be sick for months or years. These cats can still infect other cats. Later in life, the cat’s infection may become active again, and the cat will show signs of sickness. When the virus is active, it can weaken the immune system, leaving the cat at risk for different infections.

The virus can also cause cancers in infected cats. As it can take many years for the virus to become active again, many cats infected with FIV can live long and healthy lives. When first exposed to FeLV, a cat might not show any signs of illness. Some cats that are exposed to FeLV can clear the virus completely from their body. Other cats are able to control the infection, preventing illness. In some cats, the infection will become active in their body and they will develop problems such as low red blood cells (anemia) or cancer. These problems can be severe and even fatal.

Your cat can be tested for FIV or FeLV infection. There are many times in your cat’s life when your veterinarian will recommend testing. Any time your cat is sick, your cat should be tested for FIV  nd FeLV infection. If your cat goes outdoors, or fights with other cats, your veterinarian may recommend regular testing. If your cat is new to the family or you adopt another cat, testing is advised before introducing the new cat to other cats in the household. If your cat tests positive for FIV or FeLV, further tests may be recommended by your veterinarian. Even if your cat’s first test result is negative, your veterinarian may still advise repeat testing in the future.


There are no vaccines available in the United States or Canada that can protect cats from FIV infection. FIV vaccines are only available in a few countries in the world. Several vaccines to protect cats from FeLV infection are available.

Vaccination is recommended for all kittens, again one year later, and regularly for cats that have access outdoors. Adult indoor-only cats living alone or with uninfected cats may not need to be vaccinated after the first 2 years. Your veterinarian will help assess your cat’s vaccination needs.

There are no treatments for either virus that will get rid of the infection. Infected cats should visit their veterinarian for regular check-ups as this will help the cat live as long as possible with good health. Your veterinarian will advise on blood testing, vaccinations, and parasite prevention. High-quality commercial diets are recommended; raw food diets may cause serious infections.


Infected pet cats should live indoors so they don’t infect other cats. Other cats in the same household should be tested for FeLV and FIV. In some cases, cats that live together may need to be separated to avoid the spread of infection. Your veterinarian will help you determine what the best plan is for you and your cat(s).

Stress may play a role in triggering the virus to become active again. If there are other cats in the home, or a shortage of food bowls, water bowls, and litter boxes, it may cause stress because most  cats do not like to share. Keeping litter boxes, and food and water bowls clean is also important. More information about what your cat needs to feel safe and secure indoors can be found at www.catfriendly.com/healthyenvironment. Your veterinarian is your partner in caring for your infected cat.

With regular healthcare checkups and a low-stress life, cats infected with FIV or FeLV  ay live happy and healthy lives for many years


Blog source: https://catvets.com/guidelines/client-brochures#cattovet

About CVC

Chappelle Veterinary Clinic is a full service Veterinary Clinic which offers a wide range of veterinary care for cats and dogs, including routine exams, vaccinations, preventative care, diagnostics, surgery, spay and neuter, wellness services, dental cleaning, emergency and more.

Working Hours

Monday 8:00 AM – 6:00 PM
Tuesday 12:00 PM – 9:00 PM
Wednesday 8:00 AM – 9:00 PM
Thursday 8:00 AM – 6:00 PM
Friday 8:00 AM – 6:00 PM
Saturday 8:00 AM – 3:00 PM
Sunday Closed

Contact us

14128 28 Avenue SWEdmonton, AB T6W 3Y9

© 2023. Chappelle Vet Clinic. All rights reserved.