bioRxiv : the preprint server for biologyApr 10, 2026

Changes in Gut Bacteria Linked to Dog Epilepsy Compared to Healthy Dogs

Gut-Brain Axis Weekly Brief ↗PubMed ↗DOI ↗

Updated Jun 27, 2026

Abstract

Essence

Canine idiopathic epilepsy was linked to modest fecal microbiome differences, including a Collinsella ASV enriched across multiple analysis methods.

Evidence

This was a pairwise case-control observational study comparing fecal 16S rRNA microbiomes from 49 dogs with idiopathic epilepsy and 49 control dogs.

Caveat

Household explained about 69% of microbiome variation and the group shift was modest, so the study cannot establish mechanism or causality.

Simplified

BACKGROUND: Idiopathic epilepsy (IE) is the most common chronic nervous system disorder of dogs, and its cause is poorly understood. Emerging evidence suggests that microbiome alterations can occur with IE via the microbiota-gut-brain axis. Therefore, we analyzed the fecal microbiomes of 98 dogs (49 IE, 49 control) in a pairwise case-control observational study using 16S rRNA gene sequencing.

RESULTS: Although the microbial community was mostly similar between groups, IE was associated with a modest but significant shift in Weighted-Unifrac distance (P = 0.042). We used six differential abundance (DA) methods to identify differentially abundant amplicon sequencing variants (ASVs) between IE and control groups. Notably, oneASV was found to be significantly more abundant in IE dogs by all six methods. The gut microbial compositions varied drastically across households (accounting for about 69% of the total variation), but did not have significant differences between sex, age, or breed. Phenobarbital administration in IE dogs had a significant effect on seizure control, and was not associated with changes in the microbiome. Collinsella

CONCLUSION: Our findings suggest a relationship between gut microbiomes and IE. However, the specific mechanism needs to be further investigated.