I give it to my dogs who are reaching old age. Old dogs usually have liver issues and milk thistle is a good ingredient for them. It's also recommended by my vet too. One thing I'm not happy with is that it's not alcohol free which may be harmful to dogs but I guess a small amount may not be significant.
Good product generally for detoxifying an already toxic over-stressed liver. I however question the ALCOHOL content, which in itself requires liver detox....... I'd prefer ALCOHOL FREE products for liver support/detoxifying