Clinical Effects of Faecal Microbiota Transplantation as Adjunctive Therapy in Dogs with Chronic Enteropathies-A Retrospective Case Series of 41 Dogs

Simple Summary Chronic enteropathy is common in dogs, but not all dogs will respond satisfactorily to standard treatment. A few case reports suggest that faecal microbiota transplantation (FMT) can be used in dogs if standard treatments fail. Here, we report the effects of faecal microbiota transplantations in 41 dogs with chronic enteropathy, with a follow-up time of 3-41 months. None of the dogs had previously responded satisfactorily to standard treatment. Most dogs received three FMT treatments with 10-20 days' interval in between. The treatment was given in parallel with the maintenance medical treatment and diet the dog was already being treated with. After treatment, 31/41 dogs had decreased clinical signs, with most dogs showing less diarrhoea and/or becoming more active. From 16 dogs, faecal samples were taken before the first FMT. Dogs with a more severe dysbiosis, as indicated by a severely increased faecal dysbiosis index, responded more poorly to FMT compared to those dogs with milder form of dysbiosis. Our study supports previous case reports that faecal microbiota transplantation can be useful as an adjunct to the standard treatment of dogs with chronic enteropathy. Chronic enteropathies (CE) are common in dogs, but not all affected dogs respond to standard therapy. Successful responses to faecal microbial transplantation (FMT) in dogs with non-responsive CE have been reported in two case series. The objective of this retrospective study was to describe the clinical effects of FMT as an adjunctive therapy in a larger population of dogs with CE. Forty-one dogs aged 0.6-13.0 years (median 5.8) under treatment for CE at one referral animal hospital were included. Dogs were treated with 1-5 (median 3) FMTs as a rectal enema at a dose of 5-7 g/kg body weight. The canine inflammatory bowel disease activity index (CIBDAI) was compared at baseline versus after the last FMT. Stored faecal samples (n = 16) were analysed with the dysbiosis index. CIBDAI at baseline was 2-17 (median 6), which decreased to 1-9 (median 2; p < 0.0001) after FMT. Subsequently, 31/41 dogs responded to treatment, resulting in improved faecal quality and/or activity level in 24/41 and 24/41 dogs, respectively. The dysbiosis index at baseline was significantly lower for good responders versus poor responders (p = 0.043). Results suggest that FMT can be useful as an adjunctive therapy in dogs with poorly responsive CE.