The gut microbiome of companion animals profoundly influences their physical and psychological health, and diet, antibiotic use, and stress all affect microbiome welfare outcomes.
Microbiome welfare is invisible but consequential: disrupted gut bacteria affect immune function, mood regulation through the gut-brain axis, and susceptibility to inflammatory conditions. Dogs and cats with compromised microbiomes experience gastrointestinal discomfort, anxiety, and reduced disease resistance — welfare harms that manifest behaviourally but whose root cause is often unrecognised. Dietary quality, judicious antibiotic use, and microbiome-supportive feeding practices are emerging as important components of comprehensive companion animal welfare.