FeLV and FIV

Q. What are feline leukemia and feline AIDS?

Elaine Wexler-Mitchell, D.V.M., says: Feline leukemia virus (FeLV) is a potentially fatal virus to cats. It is passed by direct cat-to-cat contact and by a queen to her kittens. Clinical signs associated with FeLV are nonspecific and can range from anemia to immunosuppression to tumor formation. FeLV can cause latent infections that may not produce clinical signs for months or years. Testing and identifying FeLV positive cats is essential to controlling the infection. Cats at risk for exposure to FeLV include outdoor cats; stray cats; feral cats; multicat households where newcomers are brought in without isolation and testing; FeLV positive households; and households with unknown FeLV status. Vaccination is recommended for cats who test negative but who live in environments where these possibilities for exposure exist. Some veterinarians recommend that all kittens receive an initial FeLV vaccination series since their risk exposure may not yet be defined (i.e., may or may not go outside in the future). Initial vaccination for this noncore vaccine is at least eight weeks of age, then four weeks later, and then annually. Changes in your cats home environment could increase or decrease his risk; subsequent vaccination decisions should be based on these risks. Vaccination ensures fair to good immunity.

Feline AIDS is caused by the feline immunodeficiency virus (FIV), which is strictly a feline virus but similar to human immunodeficiency virus (HIV). The virus suppresses the immune system, but infected cats don't deteriorate as rapidly as cats infected with FeLV; many infected cats live normal life spans. The virus is usually passed through cat bites, so outside cats who fight are most at risk for infection. A vaccine for FIV was developed in 2002, but it does not protect against all strains of the virus. Healthy cats vaccinated against FIV test positive when given routine viral screening tests, so the results can be dangerously misinterpreted. At this time, vaccination is only recommended in situations deemed necessary by your veterinarian.

Good diagnostic tests exist that screen for these viruses; therefore, you should know the FeLV and FIV status of your cat so that you know if your cat is potentially contagious or may get sick and die.

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