Feline Immunodeficiency Virus, or FIV, is a retrovirus affecting members of the biological family of cats. Retroviruses work differently than typical viruses in that their genetic information is stored in RNA. They undergo a reverse (retro-) transcription to synthesize DNA within the cell of the cat, whose modified DNA is coded back into RNA to ultimately make proteins. Normal viruses, by contrast, simply begin with DNA. Of the few retroviruses to which cats are susceptible, FIV is the one most closely related to HIV. Importantly, however, humans cannot be infected with FIV, and felines cannot be infected with HIV.
Much like HIV, it is possible for FIV to cause a cat to progress to Feline AIDS. To say that a cat that has developed AIDS means that a special cell which is the bulwark of the feline immune system, the CD4+ T cell, has dipped below a certain concentration. Recent research has suggested, however, that a surprisingly high percentage of cats infected with FIV may never progress to Feline AIDS status. Furthermore, many cats whose CD4+ levels do fall below the critical level are clinically normal; without a blood test, one would never know the cat was infected.
Despite the fact that many FIV-positive cats live long, relatively healthy lives, some shelters are reluctant to accept them into their programs. The Nine Lives Foundation in Redwood, California is one shelter that gives these cats a chance. Run largely by a dedicated group of volunteers, the shelter houses several hundred cats in-house, with even more residing in foster homes. Unlike many California rescues, Nine Lives accepts FIV-positive cats into their program. People drive from all over California to bring cats to the facility. Upon arrival, the Nine Lives Foundation treats any medical conditions the cats have, performs spay/neuter surgery, and houses them until they are adopted.
Recently, we visited the Nine Lives facility to collect some samples. Pictured below is Brutus, an FIV-positive cat who is currently living at Nine Lives and is available for adoption. He’s a big, cuddly guy who is undoubtedly more interested in treats than in science. Nevertheless, he was happy to share his special poop with us in exchange for some scratches under the chin.
Post written by Alex Martin, a UC Berkeley undergraduate working with the Berkeley shelter and kittybiome to study how FIV status might affect the kitty microbiome