Based on nutrition listed, ..

I have a 3 year old Great Dane with joint problems and sensitive skin and a 6 year old Great Dane with smaller frame who is very active and doesn't act like a senior at all. I was thinking about putting them on a really good healthy food and I've narrowed it down to Innova Large Breed. The only thing left to decide is whether I should put them both on Senior or Adult. On one hand the 6 year old is a senior and the 3 year old has joint problems, like senior dogs. On the other hand the 3 year old is an adult and my 6 year old is much more energetic and active than he is.

So I took the nutritional break down of both foods and found these to be the biggest differences in content:

Adult formula has more than extra 50% of Leucine, Folic Acid, Omega 3, Fiber than the Senior. Adult also has more than extra 25% of Fat, Biotin, Linoleic Acid as compared to the Senior. All other dosages are virtually the same.

So, in my case, are these extras good for my dogs, or is Senior the way to go?

Innova is great food--I applaud your choice. You might want to check out Nature's Variety as well. These are both all natural foods and your large dogs will do well on them. A good quality adult dog food will be fine for both of them. The main difference I see here is fat content and antioxidants. Unless your dogs are overweight, the fat content is not an issue, and the extra antioxidants will be of value to both dogs, especially as they get older. Folic acid is water soluable, so your senior is not going to get too much, and it helps with energy. Being big dogs, and one of them with joint problems already, consider adding a joint supplement--Synovi-G3 is excellent, as is Missing Link with Glucosamine.