I would ask the vet. Not all probiotics are created equal.
Alot of dog probiotics seems to be mixed with digestive enzymes too.
I personally used to take 8 million units but realized that was not nearly enough. Now i take 50 million units. Your vet could recommend based on what he thinks is causing the problem.
I would do a search and kinda research some of the products and then narrow it down to a few then ask the vet
