Feline leukemia spreads through saliva, blood, and urine
Feline leukemia virus (FeLV) passes from one cat to another mainly through saliva. An infected cat sheds the virus in its mouth, and another cat picks it up by grooming the infected cat, sharing food bowls, or being bitten during a fight. The virus can also spread through blood (via bites or scratches that break the skin) and through urine and feces, though saliva is the most common route.
A cat does not need to have symptoms to spread feline leukemia. Many newly infected cats show no signs at all for weeks or months, so they can pass the virus to other cats without anyone knowing they are sick. This is why indoor cats living with an infected cat are at high risk, even if the infected cat seems perfectly healthy.
Feline leukemia does not spread to humans, dogs, or other species. It is a virus that affects only cats and some other wild felines. You cannot catch it from your cat, and your cat cannot catch it from you.
Key Takeaways
- Feline leukemia spreads mainly through saliva when cats groom each other, share food and water bowls, or bite during fights.
- An infected cat can spread the virus even when it shows no symptoms, making it impossible to know by appearance alone whether a cat is contagious.
- Bites and scratches that draw blood can transmit the virus, which is why outdoor cats and cats that fight have higher risk.
- Feline leukemia does not spread to humans, dogs, or other animals—it affects only cats.
- A mother cat can pass feline leukemia to her kittens before or shortly after birth.
Why saliva is the main transmission route
Saliva carries a high concentration of feline leukemia virus, which is why grooming is such an effective way for the virus to spread. When an infected cat licks another cat's face, ears, or body, virus particles enter through the mouth and nose of the uninfected cat. Cats that live together and groom each other regularly are at especially high risk.
Shared food and water bowls also pose a risk. If an infected cat eats from a bowl and then an uninfected cat eats from the same bowl shortly after, the virus can enter through the mouth. This is why veterinarians recommend separate bowls for each cat in a multi-cat household, particularly if one cat's infection status is unknown.
Bites, scratches, and blood transmission
When cats fight, bites and scratches that break the skin can transmit feline leukemia through blood. Outdoor cats and cats that roam freely have higher exposure to other cats and therefore higher risk of being bitten. Even a small puncture wound from a bite can allow the virus to enter the bloodstream.
Indoor cats are at lower risk of transmission through bites simply because they have fewer encounters with other cats. However, if an indoor cat lives with an infected cat, the risk from bites during play or conflict is real, even if the cats generally get along.
Mother-to-kitten transmission
A pregnant cat infected with feline leukemia can pass the virus to her kittens before they are born or through her milk after birth. Kittens born to an infected mother have a high chance of becoming infected themselves. Some kittens may be born already infected, while others may pick up the virus during nursing.
This is one reason why testing a cat before breeding is important, and why kittens adopted from shelters or rescue organizations should be tested for feline leukemia. A kitten that tests positive early in life may or may not develop disease, depending on whether its immune system can clear the infection.
Why outdoor and stray cats face higher risk
Outdoor cats have more contact with other cats than indoor cats do, which increases their exposure to feline leukemia. Stray and feral cat colonies often have higher rates of infection because cats live in close quarters, share food sources, and engage in fights. A single infected cat in a colony can spread the virus to many others over time.
Cats that spend time both indoors and outdoors (sometimes called "indoor-outdoor" cats) can bring feline leukemia home to indoor cats that have never left the house. This is a significant risk factor for multi-cat households where one cat has outdoor access.
What does not spread feline leukemia
Feline leukemia does not spread through the air like a cold or flu virus. You do not catch it by being in the same room as an infected cat or breathing the same air. It requires direct contact—saliva, blood, or urine—to transmit.
Casual contact such as petting an infected cat, handling its litter box, or touching surfaces it has walked on does not transmit feline leukemia to you or to another cat. The virus is fragile outside the body and dies quickly in the environment. However, good hygiene practices—washing your hands after handling an infected cat and before handling an uninfected cat—are still a sensible precaution.
How long an infected cat remains contagious
A cat infected with feline leukemia can shed virus for the rest of its life. Some cats clear the infection on their own within a few weeks or months, but others remain persistently infected and contagious indefinitely. There is no way to know which cats will clear the infection and which will not without testing over time.
This means an infected cat poses a transmission risk to other cats for as long as it lives. If you have an infected cat and an uninfected cat in the same home, they should be kept separate to prevent transmission, or the uninfected cat should be tested and monitored closely by a veterinarian.
Frequently Asked Questions
Can I catch feline leukemia from my cat?
No. Feline leukemia affects only cats and some wild felines. Humans cannot be infected with this virus. You can safely pet, handle, and care for an infected cat without risk to yourself.
If my cat is infected, will all my other cats get it?
Not necessarily. Transmission depends on how much contact the cats have. Cats that groom each other or share bowls are at high risk, but cats that are kept completely separate may not transmit the virus. Your veterinarian can test uninfected cats and discuss ways to reduce transmission risk in your home.
How long does the virus survive on surfaces or in litter boxes?
Feline leukemia virus is fragile and dies quickly outside the body—usually within a few hours in the environment. Litter boxes, food bowls, and bedding do not pose a significant transmission risk if cleaned regularly. Standard household cleaning is sufficient.
Can an indoor cat get feline leukemia if it never goes outside?
Yes, if it lives with or has contact with an infected cat. Indoor cats can also be infected if they were exposed before being brought indoors, or if an infected cat is brought into the home. This is why testing new cats before introducing them to your household is recommended.
Is a cat still contagious after treatment?
There is no cure for feline leukemia, only treatments to manage symptoms and support the immune system. A cat that is infected remains contagious for life. Treatment can help an infected cat live longer and feel better, but it does not eliminate the virus or stop transmission to other cats.