Isolation of Toxoplasma gondii from the feces of naturally infected cats

The feces of 1,023 stray or unwanted cats on the island of Oahu, Hawaii, were examined for oocysts of Toxoplasma gondii. Oocysts, proven to be Toxoplasma by inoculation of mice, were found in the feces of six cats. This is the first report of the isolation of Toxoplasma from feces of cats in their natural habitats, Antibody to Toxoplasma was found by the dye test in the sera of 20% of 522 of the cats tested. Of 202 cats that appeared to be sexually immature (under six months of age), only 7% had antibody, whereas of 320 judged to be older than six months, 29% had antibody.