What Happens to a Cat After Being Exposed to FeLV

If the cat becomes infected from exposure to FeLV, 2-4 weeks later, in the acute stage of infection, large numbers of the virus can be found in the bloodstream (viremia).

Cats in the acute phase may not show signs of disease. If they do, the signs are usually fever, lethargy, diarrhea and swollen lymph nodes (lymphadenopathy). When a cat is exposed to FeLV, several things can happen:

1. Some cats will not be infected due to inadequate exposure and a good immune response.

2. Some cats will develop a latent infection; these cats will not be able to destroy all of the viral RNA, but will be able to hold it in check. This is called a latent or regressive infection. These cats usually show no signs of infection and usually do not shed virus in their saliva or other body secretions.

3. Some cats will become persistently infected; these cats will not develop an adequate immune response and will remain permanently infected with FeLV. This is called a progressive infection.

These cats will shed large amounts of virus in their saliva and often develop FeLV-associated diseases within a few years. Age is a very important factor in determining what will happen after a cat is exposed to FeLV.

Almost all FeLV-exposed kittens less than 8 weeks of age will have persistent viremia, show signs of disease during the acute phase, and become permanently infected.