The gut microbiome plays a significant role in feline health and welfare, with dietary choices and antibiotic use having lasting effects on microbiome composition and function.
Microbiome disruption causes welfare harms through digestive discomfort, diarrhea, altered nutrient absorption, and potentially through effects on immune function and behavior. The gut-brain axis in cats, as in other species, means microbiome composition may influence mood and stress responses. Antibiotic use, which causes significant microbiome disruption, should be reserved for genuine bacterial infections rather than used preventively or for viral conditions — a welfare consideration that aligns with the antimicrobial resistance concern. Dietary choices that support microbiome health are simultaneously welfare and health investments.