Feline Leukemia Vaccine

Not sure if anyone can help or give me advice on this but it was suggested by a breeder not to get the feline leukemia vaccine for my Maine Coon because of the possible side effects - but my vet however is recommending it. What are your thoughts on it?

Hi there,
The feline leukemia, or FeLV, vaccine is very common and standard. This is the first time I've heard of it not being recommended!

FeLV is a contagious and potentially life-threatening retrovirus that can weaken a cat's immune system, making them susceptible to various infections and diseases. It is one of the most common infectious diseases in cats.

The FeLV vaccine works the same way most vaccines do - by stimulating a cat's immune system to produce antibodies that can neutralize the virus if the cat is ever exposed to it. The vaccine can significantly reduce the risk of a cat contracting FeLV or lessen the severity of the disease if the cat does become infected.

Because feline leukemia is so contagious, the FeLV vaccine is recommended for all cats, especially those who have a higher risk of exposure to the virus, such as outdoor cats or those living in multi-cat households where there might be a potential for the virus to spread.

Side effects are generally mild and uncommon. Most cats tolerate the vaccine well without any adverse reactions.

Common and mild side effects may include:

• Mild soreness at the injection site


• Mild lethargy or decreased appetite for a short period


• Low-grade fever

In rare cases, more severe reactions can occur, such as:

• Allergic reactions: These may include facial swelling, difficulty breathing, or hives. Allergic reactions are very rare but require immediate veterinary attention.


• Injection site reactions: Some cats may develop more pronounced swelling, redness, or even a small lump at the injection site. This usually resolves on its own, but if it persists or becomes concerning you may need to call your vet.

Cats who should not get the FeLV vaccine include:

• Feline Leukemia Positive Cats: If a cat has already tested positive for feline leukemia virus (FeLV), there is no benefit to vaccinating them against the virus. The vaccine is intended for preventing the infection, not treating it.



• Sick Cats: If your cat is currently ill, has a fever, or is experiencing any health issues, it's best to postpone vaccination until they have fully recovered. Vaccinating a sick cat can put additional stress on their immune system.



• Kittens Younger Than Eight Weeks: The feline leukemia vaccine is not typically administered to kittens younger than eight weeks old. Kittens receive immunity from their mother's milk during the first weeks of life, and vaccination is usually started after this passive immunity wanes.



• Immunocompromised Cats: Cats with weakened immune systems, such as those with certain chronic illnesses or undergoing immunosuppressive treatments, may not be suitable candidates for vaccination. In these cases, the decision should be made in close consultation with your veterinarian.



• Cats with a History of Severe Vaccine Reactions: If your cat has had a severe allergic reaction to previous vaccinations or has a known sensitivity to any vaccine components, it may be necessary to avoid certain vaccines, including the feline leukemia vaccine. Your veterinarian can advise on alternative strategies for protecting your cat's health.


Without knowing which side effects your breeder was worried about, the only ones who can answer whether your Maine Coon should have this vaccine are you and your vet.

I hope your vet was available to discuss it at length with you to help you make the right decision!

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