Chronic gingivitis in a colony of cats infected with feline immunodeficiency virus and feline calicivirus.

The inadvertent introduction of feline calicivirus into a colony of 19 experimental cats, 13 of which were infected with feline immunodeficiency virus, resulted in the development of chronic gingivitis in nine animals. Of these, six were infected with both viruses, one with the immunodeficiency virus alone and two with the calicivirus alone. The gingivitis was generally more severe in the cats infected with both viruses, suggesting that feline immunodeficiency virus may make cats infected with calicivirus more susceptible to chronic gingivitis.