Cyniclomyces guttulatus Infection in Dogs: 19 Cases (2006-2013)

Cyniclomyces guttulatus, a gastrointestinal yeast of rabbits, is considered an uncommon, nonpathogenic, "pass through" organism and possible opportunistic pathogen in dogs that consume rabbit feces. This retrospective study aimed to characterize the presenting complaint, clinical findings, location of organisms, and final diagnosis of dogs in which yeast morphologically consistent with C. guttulatus were identified at a veterinary teaching hospital from 2006-2013. The prevalence of C. guttulatus infection in a general population of dogs from a regional animal shelter was also determined. Nineteen dogs were retrospectively identified as diagnosed with C. guttulatus infection. Among these, 79% presented with a chief complaint and/or clinical signs consistent with gastrointestinal tract disease. The most common clinical sign was chronic diarrhea. The majority of dogs had C. guttulatus identified cytologically within samples obtained from the gastrointestinal tract; however, four dogs had C. guttulatus identified in non-gastrointestinal tract samples, including a nasal biopsy (one dog) and urine (three dogs). C. guttulatus was not identified in any of 105 shelter dogs evaluated, suggesting low prevalence of C. guttulatus in our region. These findings suggest that additional studies to determine if C. guttulatus is a potential cause or consequence of gastrointestinal illness in dogs may be warranted.