Prevalence of Cryptosporidium infection among domestic cats in the Tokyo Metropolitan District, Japan.

From February, 1988 to February, 1989, an epidemiological survey for feline cryptosporidiosis was carried out on domestic cats that had been committed to the Tokyo Metropolitan Animal Protection Center by owners residing in the Tokyo Metropolitan District. Of a total of 608 cats, 23 (3.8%) were found to have Cryptosporidium oocysts. The percentage of cats positive for the infection ranged from 0 to 13.6% by month. The infection was found to be more common in "baby" and "young" cats than in "middle" and "old" ones. No significant difference in incidence was shown between the sexes. In each positive cat, no apparent clinical symptom such as diarrhea was found, and the size of the oocysts measured from 4.3 to 4.7 microns in diameter (small type).