2015 ACVIM Forum Research Abstract Program

Nine of 16 healthy dogs (56%) receiving metronidazole produced yellow, soft to liquid feces on one or more occasion(s) while they were medicated. This did not happen in the untreated control group. No significant changes were observed in serum concentration of cobalamin and folate in all 3 groups. In the control dogs, only E. coli showed a significant change in abundance over time between D0 and D21 (P < 0.05). In contrast, in G2 and G3 several of the bacterial groups showed significant changes in abundance over time. Because the responses in these 2 groups were similar, they were combined for statistical analysis. Significant increases in abundance compared to baseline were observed after metronidazole administration for E. coli (P < 0.001 at D14 and D28), Streptococcus spp. (P < 0.001 at D14), and Bifidobacteria spp. (P < 0.001 at day 14 and P < 0.05 at day 42). In contrast, significant decreases in abundance were observed for Faecalibacterium spp. (P < 0.001 at D14 and P < 0.05 at D28), Ruminococcaceae (P < 0.001 at day 14 and P < 0.05 at day 42), and Blautia spp. (P < 0.01 at D14). No significant changes in abundance due to metronidazole were observed for C. perfringens and Lactobacillus spp.