Really until a dog is done growing it can be considered a puppy, and likewise it will benefit best from some form of puppy food. The breed of the dog will be the biggest factor in determining when this stage of life ends, with larger breeds taking longer to fully mature. Some dogs, like Labrador retrievers, can be eating specialized puppy food well into eighteen months of life in order to best support a full and healthy growth phase.
The only difference is the Purina Pro Plan small breed kibble adding a tad more protein by only 1%. Both list real meat as the first ingredient but the second is meat by-product for both brands. With that being said, Purina Pro is one of our favorite foods for smaller breeds like the Yorkie or the Shih-tzu, due to that added protein.
As I love all my dogs I have fed most of them Purina one as I’ve learned of it. I have heard Purina Pro plan was better, yet my last three dogs have had very long lives on Purina One. I have a 3 month old golden retriever puppy who is on Purina One Large Breed Puppy food and doing great. He loves the food and jumps up and down in joy when he is getting ready to eat from his bowl!
It could be down to a bad batch or wrong storage conditions, but it could also result from unpredictable changes dog food manufacturers are so fond of. Still, this is a great starting point if you’ve pedigree adult dog food never bought Purina kibble. I have watched as all the high end brands roll out in over the years. My first dog I had from 1970 until 1987 and I believe he was fed Purina Dog Chow his whole life.
Meat by-products are somewhat controversial as a food source, made from grinding rendered parts of poultry carcasses and can contain beaks, bones, and offal. Whilst not necessarily harmful for your pet, they are not the purest of ingredients and there is a growing number pedigree wet dog food of pet owners that object to these by-products being present in dog food. They are often used to boost the protein content within, however all the above products are highly rated online having produced good results for their pups, so don’t let this put you off them.