So far I have not had anything bad happen to any of my dogs but on the other hand I haven't noticed any improvements either, It is a pain to mix because I have to use milk or my dogs wont touch. In fairness they free feed and are a bit spoiled. I was thinking about re-ordering but the price is nearly double from the first 9 jars I bought. Inn reading the reviews I have noticed some had shaking in two of my dogs and it hasn't helped my SS digestive issues. So I am thinking I am just wasting money and shoud just feed quality feed and fresh foods without this additive and save $$$