Are probiotics worth it for cats?

Mixed evidence. The strongest research base for probiotics in cats is for diarrhea-related conditions, where specific strains have shortened symptom duration in studies. For general gut health in otherwise-well cats, the evidence is much weaker. The other problem is the market: many pet-store probiotics don’t actually contain live bacteria by the time you open the bottle, because the storage and shipping conditions kill the cultures. If you want to try one, ask your vet for a veterinary brand with published research behind the specific strain, rather than picking off a pet-store shelf.

When to call a vet: if you’re considering probiotics because of chronic vomiting or diarrhea, do the vet workup first. Symptomatic treatment can mask underlying conditions.