Is it OK to feed my puppy adult food? There might be several reasons why someone might consider feeding their puppy adult food. Often times, it is a matter of convenience, there is already an adult dog in the house and it is easier to buy one food instead of two. Sometimes the puppy wants to eat what “big sister or brother” is eating. But sometimes pet owners feed their puppies an adult dog food in the mistaken belief that they can feed lower amounts of calcium and phosphorous.
High levels of calcium and phosphorous have been implicated in causing or worsening joint disease, such as osteoarthritis or hip dysplasia. And it is true that abnormally high amounts of those two minerals can result in an increase in the level of bone being formed, especially during growth. This was a huge problem in the 1970’s and 80’s when many breeders gave supplements in hopes of their puppies growing larger in stature than they otherwise would.
Puppy food does have slightly higher levels of calcium and phosphorous when compared to most adult dog foods. Puppy food also has a higher fat and protein content, meaning there are more calories per bite than the adult version of the same brand. Well meaning people will recommend that the adult formulas are fed because of the lower calcium and phosphorous, however these minerals are only slightly less than the puppy formula. In order to meet the protein and caloric needs of a puppy eating an adult formula, a substantially larger quantity of adult formula must be fed, resulting in the ingestion of even more calcium and phosphorous than the puppies would have had they just stuck with the puppy formula!
Veterinary nutritionists spend years of their lives studying nutrition in animals. It would be highly unlikely that anyone, no matter how good their intentions might be, would come up with a better plan in their own kitchen. As long as you are feeding a trusted brand-name dog food, and not some boutique brand that wasn’t designed by a veterinary nutritionist, you can believe and feel confident in the recommendations of the manufacturer.