We have been using probiotics for the past year (along with other supplements as well) because of Sissy's digestive disorder. Angel gets them along with Sissy as a preventative measure.
We order ours from
Holistic Veterinarian Pet Nutritionist Holistic Pet Care as this is the only one I've seen that can site testing where exposure to high heat for several days did not change the molecular make-up of the product. The price is reasonable as you only use one a day. We open them and sprinkle on their food - but we also use The Honest Kitchen which when rehydrated is the consistency of canned food.
Did your vet test for parasites? What kind-of food are you using and has she had any other symptoms?