"I mix a teaspoon full in my 9 year old Coonhound mix's food as well as our Golden Retriever puppy's food. The pup is only 7 weeks old and softening the food a little makes it easier to eat and the 9 year old's coat glistens now. So far no digestive changes or anything. I would say just don't over due it on their food to make it go further, and maybe only one meal a day so they don't come to expect it and turn their head when they don't have it. Overall, we highly recommend this for all dogs, young and old."