Virus in Cats Closely Mimics the Symptoms of AIDS in Humans
California researchers have discovered a virus in cats that causes symptoms strikingly similar to those caused by the AIDS virus in humans, a development that they say could make cats an ideal animal model for AIDS research.
In a report Thursday in Science magazine, the University of California, Davis, scientists emphasized that the cat virus is different from the human AIDS virus and apparently does not infect people.
Although the AIDS-like disease is probably fatal to a cat, they urged people not to kill off their pets if they show signs of an immuno-deficiency. Veterinarians should be able to diagnose the disease and may be able to treat some of the symptoms, said Janet Yamamoto, a senior immunologist and co-author of the report. “Please consult your vet before you do anything drastic to your cats.”
The scientists said a limited survey of blood samples seen at the university’s veterinary medicine school has confirmed the existence of the virus in diseased cats from many different Northern California areas.
The new virus was discovered in a Petaluma colony of 42 homeless cats retrieved from veterinary hospitals, homes and pounds. The cats were housed in six open pens and suffered only normal mild illnesses during a 14-year period until a female kitten from San Francisco was introduced to one of the enclosures in 1982.
The cat had bouts of diarrhea and infections for two years and, in the third year, became thin and anemic, eventually developed abnormal neurological behavior and died.
In 1985, the researchers reported, other cats in the same pen developed similar symptoms and 10 died. Of the 15 remaining cats from the pen, 13 are sick and eight have tested positive for the virus.
The scientists also said blood and serum from sick cats proved highly infectious when injected into healthy cats, causing them to develop immune system diseases within months.
The cat virus attacks T-cells, white blood cells that are crucial to defense against disease. These are the same cells that are attacked by the human AIDS virus.
The cat virus is also related to feline leukemia virus, which causes a form of leukemia in cats and for which a vaccine has been developed.
Yamamoto said tests have shown that, so far, no humans associated with infected cats have developed the virus.
The new cat virus could help scientists in their search for human AIDS treatments and a vaccine because a barrier in AIDS research so far has been that there is no way to cause the disease in laboratory animals for testing.
Two viruses can cause AIDS-like symptoms in chimpanzees, but these are somewhat different from human AIDS. The Davis scientists said the cat syndrome might be an easier model to work with because cats are cheaper than chimps and because the disease appears to mimic human AIDS more closely.
