Abstract: Background - Fecal microbiota transplantation (FMT) is a growing therapeutic modality in companion animals with gastrointestinal diseases. Information on adverse events (AE) following FMTs in companion animals are scarce. However, serious AE have anecdotally been reported in cats with gastrointestinal diseases following repeat FMTs.
Objective - Describe the AE of FMT in a series of cats with underlying gastrointestinal disease receiving multiple FMTs.
Animals - Nine cats receiving at least two FMTs for acute or chronic gastrointestinal disease.
Methods - Retrospective multicenter case series. AE were graded according to the Veterinary Cooperative Oncology Group-Common Terminology Criteria for Adverse Events (VCOG-CTCAE v2) grading system.
Results - Four adult cats (median 10 years of age, range 7-14 years) and five kittens (all aged 2 months) received repeat FMTs (median 3 FMTs, range 2-6) at 5 g/kg (n=7) or 6 g/kg (n=2) via a rectal enema. Reasons for receiving FMT were therapy-resistant diarrhea (5 kittens) and chronic enteropathy (4 cats). AE included lethargy (n=7), vomiting (n=5), watery diarrhea (n=5), inappetence (n=5), fever (n=4), and abdominal pain (n=2). AE after FMTs were categorized as grade III (n=2), grade II (n=5), and grade I (n=2). Cats showed recovery with metronidazole and anthelmintics (n=4), gabapentin (n=2), marbofloxacin and anthelmintics (n=1), pradofloxacin (n=1), and self resolvement (n=1).
Conclusions and Clinical Importance - Repeat FMT in cats with gastrointestinal disease may cause clinically relevant AE, of which clinicians should be aware. Prospective systematic studies evaluating AE after FMT administration in cats are needed.
