Hi Randy-
Unlike fats and carbohydates, proteins do not store in the body, so when fed in excess will be excreted from the body as waste. This is why it was originally thought high protein diets cause kidney damage.
According to my current edition textbook (I’m studying to become an RVT), dry pet food for dogs should not contain more than 40% protein on a dry matter basis. Anything more than that is not being used by the body. I personally have found my dogs do well on foods around 26% protein and 16% fat or under. You can find puppy foods with those %’s usually or at least close to it.
I have however read literature written by a nutritionist that states that puppies need between 22-25% protein.
As for fiber, I find anything over 5% MAX fiber to be too high. You will usually find 5% or more fiber in weight control diets.
Hope this helps!
