I'm no expert on the protiens or anything like that. But I will say...my dach ruby has to be on hills prespricpt diet (K/D) for her kidney diabetes. Which is low in phosurus and protien, and high in fat. Her breath is "better" and her "poots" are less stinky.
She has smaller poops, and they are not as rank as they used to be.
I hate that she is on hills as I know its not the "best" food in the world...but given the vet said its an absolute must (and its working with her kidneys as well)...I tollerate it.
I just wanted to add my two cents that on a lower protien diet...it seems to have helped "stinky" issues. I also noticed her body smell is not as "musty" when she's dirty.
I mean...still needs a bath...but no longer want to hold her out the window when we go on a car ride. LOL