Characterization of vaginal microbiotic yeasts of bitches in distinct stages of the oestrous cycle

Abstract

Yeasts are commensal organisms frequently isolated from the skin and mucous membranes of domestic and wild mammals. Although yeasts are frequently isolated from womens vaginal mucus, similar studies in canine are rare, therefore their behaviour during the canine oestrous cycle is unknown. The purpose of this study was to isolate yeasts from the vaginal microbiota of bitches and to evaluate their behaviour in different stages of the oestrous cycle. We examined 75 samples of mucus from the vaginal cavity of 75 domestic bitches and 224 samples from 14 experimental bitches. The stages of the oestrous cycle were characterized through vaginal cytology and clinical observation of bleeding, vulvar oedema and pucker. Samples were examined visually, and also cultured in Sabouraud dextrose agar with chloranphenicol, at 37 ºC for 10 days. The yeasts were classified according to their macro and micro morphology, biochemical tests, germination tube and micro culture. Yeasts were isolated from 25 (33.3%) samples from domestic females. Among the samples collected during proestrous, oestrous, diestrous and anestrous, 56.3% 16.7% 66.7% and 20.5% were positive, respectively. Yeasts were isolated from 147 (65.6%) samples from experimental bitches. Among the samples collected during proestrous, oestrous, diestrous and anestrous, positive samples represented 61.9%, 71.9%, 82.7%, and 57.1%, respectively. The identified species were Candida spp, M. pachydermatis and Rhodotorula spp, which are commonly present in the vaginal mucus microbiota of healthy bitches and their frequency changes with the different stages of the oestrous cycle.