It may seem like just yesterday when you brought your puppy home for the first time. But by the time he turns one year old, he will have grown by leaps and bounds and, for the most part, will be considered an adult. Of course, it all depends on his size and breed. Larger dog breeds often don’t reach full physical and emotional development until they’re closer to two years of age. Regardless, other dogs may begin treating them as adults, becoming less tolerant of their puppy-like behavior. Even if your puppy is still as playful and as mischievous as he ever was, his needs are changing. You will also need to make some changes to help him maintain his health and happiness.
When to Switch to Adult Dog Food
Your puppy needs a diet high in fat, protein, and calories to grow into a healthy adult. When he reaches adulthood, he will require a different level of nutrients, vitamins, and minerals. Adult dogs don’t burn nearly as much energy as puppies do, so continuing to feed him puppy food can cause weight gain, as well as strain on the joints.

It is best to transition your dog to a new food gradually over a five- to seven-day period. Mix in increasing amounts of the new adult food and reduce the amount of puppy food in his daily portions. This gradual change will make it easier for him to get used to the taste and consistency, and avoid the possibility of an upset tummy.
Some owners think they can switch their large-breed puppy to an adult dog food too early (for example, when he is six to eight months old) to limit caloric intake. At this point in his development, your puppy is still undergoing rapid growth. Switching him to a less energy-dense food can lead to bone development problems.
We recommend these Science Diet® adult dog foods, with precisely balanced nutrition to keep your dog active and healthy for life. They offer the same great tastes that your pup loves and is used to, but provide a more balanced nutrition for his change in lifestage to help keep him feeling young while maintaining his healthy body.