In this month’s blog I will be talking about the importance of vaccinating your cat against Feline Leukemia Virus (FeLV).   The core vaccines that have been recommend by the American Association of Feline Practitioners are as follows:  Feline Panluekopenia, Feline Herpes Virius-1, Feline Calicivirus, and Rabies. FeLV is not part of the list but is still highly recommended. Feline leukemia virus infects domestic cats throughout the world and results in death in infected cats.  The prevalence in North America is less than 5%; but it may be as high as 25% in multi-cat households where no prevention (i.e., vaccines and testing) has been done. In America only 50% of dogs and 25% of cats receive vaccines, this puts your cat at greater risk of infection. The virus is spread through saliva, nasal secretions (mutual grooming, biting, sharing of food and water dishes), blood transfusion, in utero or through milk. With so many ways for a cat to be infected, it is vital that cats be vaccinated to reduce their risk. If your cat gets FeLV, the prognosis is poor as most cats are infected will develop the disease[h1] .  Of cats with FeLV, 70-90% die between 18 months and three years of infection.  FeLV causes immune suppression, anemia, and lymphoma.  Cats with FeLV have immune systems that are more suppressed than cats with FIV because FeLV affects more of the immune system. Because their immune systems are weaker, the risk of infection by bacteria, Toxoplasma gondii, Mycoplasma haemofelis is much greater. In addition to increasing risk of secondary infection, FeLV causes two types of cancer; lymphoma and leukemia. Taken together, FeLV and the associated illnesses shorten the life span of the infected cat. The good news is that we can easily test for FeLV.  We use a Snap test, which is a cage side test that uses a little blood from the cat, and results are known with ten minutes.

One question that comes up consistently is about timing of vaccinating cats. Kittens need to undergo a Snap test prior to their first vaccine to see if they have already been infected. Second, kittens get maternal antibodies from nursing from their mothers, at about 6 weeks of age, antibodies start to wean from the kitten’s system. Thus, we need to wait until the kitten is at least 6 weeks old so that the vaccines have the highest chance of being effective. So, in general, the vaccine series should be started at 8 to 9 weeks of age, but can begin as early as 6 weeks. Vaccinations should be spread out at least 2 weeks but no longer than 4 weeks between shots. Kittens need to continue to get booster shots approximately every 3 to 4 weeks, depending on when vaccines were started, until the kitten is 16 weeks old. You can begin to vaccinate your cat for FeLV beginning at 8 or 9 weeks of age and stop at 16 weeks. However, if it is has been more than 6 weeks between vaccines, you will have to start over and your cat will need to receive at least 2 additional doses of vaccine 3 to 4 weeks apart.  All cats must have a booster 1 year later. Vaccinating for FeLV should be part of your routine vaccines because it protects against a potentially life-threatening virus and the benefits outweigh the risks.  Also at FeederCreek Veterinary Services we combine core vaccine with the FeLV vaccine.  One less shot for your cat is safer for everybody.  If you chose not to vaccinate your breeding cat colony, you will a need a yearly screening program for every cat.

What happens if you have a cat with FeLV? It is possible for cats with FeLV to live normal lives until they become sick. They must be kept inside to prevent your cat from infecting other cars. In fact scientific studies have reported that the rabies vaccine is not effective in FeLV positive.  [h2] If your cat is infected, you should not have other cats in the home or they will also become infected. Cats with FeLV should be seen by the veterinarian every 6 to 12 months for blood work, complete blood count, biochemistry profile, and urinalysis. Infected cats (both male and female) will  will need to be neutered. I recommend that any kitten that tests negative for FeLV/FIV be vaccinated for FeLV and receive annual boosters depending on your individual cat’s needs. Please discuss all these issues FeederCreek Veterinary Services.