So far there is one known probiotic that is different between dogs and humans. The other 15 known ones are the same. It’s just that their gut conditions support different colony sizes, so a human probiotic may have more of one type of probiotic than another because humans should have more of that particular probiotic. It may be that dogs don’t support large populations of that particular one, but do of a different one. If you found dog probiotics that you knew actually took that into account and they guaranteed the number of colony forming units of the particular probiotics and they had a large selection of the different strains, then it would be worth the extra money to buy dog probiotics, which BTW should be different than cat probiotics if they are really taking all of that into consideration. So far, even the best pet probiotics that I have found have lumped all animals together with the same formula, just different amounts. So my standard is to buy only probiotics that have at least 9 different strains, but over 12 is STRONGLY preferred.
