It has the same ingredients but much fresher. For instance, in the Nutros the first ingredient is "lamb meal" which means it's just a bunch of ground up lamb parts, any parts. In the Professional food the fist ingredient is "fresh lamb" which means it's more lambe meat. I had a vet tell me this years ago too. The Pro also has flax seed, rice and vitamins that just seem better than the Nutros. It's the same price too.