Repeated fecal microbiota transplantation in dogs with chronic enteropathy can decrease disease activity and...

Evaluate clinical and fecal parameters in dogs with refractory chronic enteropathy (CE) treated with repeated fecal microbiota transplantation (FMT) as adjunct treatment.

This was a prospective longitudinal observational study from September 25, 2021, to June 20, 2024. Thirty-nine dogs received 2 to 3 rectal FMTs over 1 month. Canine inflammatory bowel disease activity index (CIBDAI) and fecal samples were assessed for 6 months. Fecal samples were analyzed for dysbiosis index, bile acids, and calprotectin.

28 of 39 dogs responded to FMT. Eight dogs had a short-lasting response. Before FMT, baseline CIBDAI was equivalent in responders and nonresponders. Responders had a significantly decreased CIBDAI at 1 month, which remained unaltered at 6 months in long-lasting responders (LLRs). Baseline dysbiosis index (mean [95% CI]) was significantly lower in LLRs (-0.02 [-3.3 to 2.7]) versus nonresponders and short-lasting responders combined (N/SRs; 2.9 [-0.2 to 6.0]). Baseline percentage of secondary unconjugated fecal bile acids was higher in LLRs (65 [41 to 89]) versus N/SRs (30 [6 to 54]). Dysbiosis index decreased significantly at the time point for the third FMT in LLRs (-2.4 [-3.9 to 2.2]) but not in N/SRs (3.3 [-0.4 to 5.7]). Corticosteroid tapering was achieved in 13 responders. Mild adverse events were noted in 4 dogs.

This repeated FMT protocol was an effective adjunct treatment in refractory CE dogs, especially in dogs with no or mild dysbiosis. Marked dysbiosis and BA dysmetabolism before and after FMT appeared associated with no clinical response or a short-lasting response to FMT, potentially requiring repeated FMT.

Repeated FMT could reduce disease activity and corticosteroid usage in dogs with refractory CE.