Fecal microbiota transplantation dosing regimen accelerates clinical resolution in canine parvovirus infection: a novel spectrum-of-care approach.

Abstract

OBJECTIVE: To evaluate the efficacy of a novel spectrum-of-care fecal microbiota transplant (FMT) dosing regimen as an adjunctive therapy for canine parvovirus (CPV). METHODS: 27 client-owned dogs naturally infected with CPV were enrolled from March to November 2023 in a prospective, double-blinded, placebo-controlled clinical trial. Patients were randomized into FMT-treated (n = 19) or placebo-treated (8) groups. Along with conventional treatments, CPV-infected dogs were administered FMT (single FMT enema, then 14 days of oral lyophilized FMT capsules) or placebo (single saline enema, then 14 days of oral placebo capsules) at admission. During hospitalization, dogs were monitored daily including fecal, clinical severity, and medication scores. Feces and serum were collected at admission, day 4, day 7, day 14, and day 21 for quantification of CPV viral shedding and immune response (bead-based multiplex of cytokines/chemokines). The primary outcome variable was length of hospitalization. RESULTS: Interim analysis revealed that placebo-treated dogs had excessive study withdrawals due to worsening clinical status when compared to FMT-treated dogs (37.5% compared to 0%, respectively), leading to ethical discontinuation of the placebo arm. Fecal microbiota transplant-treated dogs had significantly reduced hospitalization length and medications required for treatment (maximum medication score) compared to placebo-treated dogs. Fecal microbiota transplant did not reduce fecal viral shedding or elicit a host immune response. CONCLUSIONS: This novel FMT dosing regimen (single enema FMT followed by oral capsular FMT), designed to be feasible for inpatients or outpatients, accelerated clinical recovery from CPV. CLINICAL RELEVANCE: In-house and commercially available FMT products were effective in CPV-infected dogs, thus broadening the spectrum of care available to these patients.