Abstract: Background – Clostridium hiranonis is a key player in bile acid metabolism and its decreased abundance has been observed in dogs with chronic enteropathies. Different protocols to conserve fecal microbiota transplantation (FMT) preparations are used in the treatment of chronic enteropathies, but the viability of C. hiranonis in those preparations is unknown. Objectives – To assess abundances of C. hiranonis over time in the feces of healthy dogs using different methods and temperatures to conserve feces: lyophilization and storage at 4°C and -20°C, and freezing with glycerol at -20°C. Animals – Six healthy dogs. Methods – Abundances of C. hiranonis were quantified by bacterial culture using Brucella Blood Agar at 36°C in an anaerobic environment. Friedman test was used to compare the abundances of C. hiranonis across time points. Results – All methods resulted in lower C. hiranonis viability, but the decrease in C. hiranonis abundance was significant only in lyophilized samples kept at 4°C and -20°C after one month (P < .0001 and P=.0055, respectively). C. hiranonis could not be cultured in 4/6 lyophilized samples kept at 4°C after one month but was cultured in 6/6 lyophilized samples kept at -20°C for one month. Conclusions and clinical importance – While all storage methods led to a decrease in the abundance of C. hiranonis, a relatively high abundance of organisms could be detected in lyophilized feces kept at -20°C and in frozen feces with glycerol. Both methods were satisfactory to conserve viable C. hiranonis for FMT preparations.
