Abstract: ：To study the molecular epidemiology of Cyniclomyces guttulatus and its pathogenicity to dog intestine, 222 fecal samples were collected from three large police dogs bases in Tianjin area. Microscope examination, separated culture, dyeing identification, yeast genome extraction and 18S rRNA gene identification of C.guttulatus in the fecal samples were carried out, and the isolated strains were studied for the pathogenicity of the dogs. Results showed that there were 35 C.guttulatus positive samples from the police dog base in Xiqing, and the positive rate was about 15.77%. The proliferation mode of the yeast was identified as germ producing yeast by dyeing. The target band was amplified by 18S rRNA gene to get about 400 bp, and 6 experimental dogs were studied for the pathogenicity. The symptoms of diarrhea and stool were found in two dogs. By fecal microscopic examination droppings of yeast or yeast spore were found. Therefore, the C.guttulatus may be as an opportunistic pathogenic bacteria, which can cause intestinal infection under certain conditions in dogs.

Key words: police dog, Cyniclomyces guttulatus, epidemiology, pathogenicity