I have an Australian Sheppard I adopted two years ago who is about 6 or 6.5 years old. I've always fed him Pedigree Complete Nutrition, yet now that he is approaching "senior" years, thought of switching to Purina One.

I've read the ingredients and they seem pretty much the same, yet have any of you gals that have used either product, or both, seen a difference in your dog?

Thanks!