After a round of antibiotics, my senior dog was left with gastrointestinal issues. We tried 3 different probiotics over several months, and I finally decided to try Bene-Bac (I was a little skeptical because it's a fraction of the price of ones the vet recommended). It made an immediate difference that was dramatic compared to others. Reviews on other websites suggest that other small animals had similar positive results. I'm hopeful that his GI problems are overwith until the next antibiotic.