16S rRNA microbiome sequences of canine donor and canine recipient (the latter before and after FMT)

The case presented is of an 8-year-4-month-old female neutered Labrador Retriever with acute haemorrhagic diarrhoea that was unresponsive to initial symptomatic and antibiotic treatment. The disease became protracted and characterised by ongoing gastrointestinal protein loss leading to significant hypoalbuminaemia. Upon referral, supportive treatment was continued and a single faecal microbiota transplantation (FMT) from a healthy donor given by rectal retention enema. Microbiome 16S rRNA sequencing of the recipient's faecal sample before the FMT revealed dysbiosis characterised by high abundance of Pseudescherichia (P.) vulneris (42.8%) and Clostridia sp (15%), and significantly reduced microbial diversity and richness compared to the donor dog. Microbiota composition of the recipient normalised 1 day after FMT, with dramatic reduction of P. vulneris and Clostridia, but a significant increase in health-associated bacteria like Peptacetobacter (formerly Clostridium) hiranonis, Fusobacterium mortiferum and Faecalibacterium prausnitzii. Microbiota diversity and richness also significantly improved after FMT. The dog improved clinically with no further treatment, and had no relapse of clinical signs by the most recent follow-up, approximately 1 year after initial presentation. While the possible contribution of initial antibiotic treatments before FMT to both the clinical picture and the intestinal dysbiosis could not be established, FMT was successful to resolve this dog's clinical signs long term. FMT should be considered a valid adjunctive treatment for canine cases with protracted acute haemorrhagic diarrhoea, even in the presence of gastrointestinal protein loss.