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When to Switch From Puppy Food to Adult Food


Just as your nutritional needs have changed since you were a baby, what was suitable for your dog as a puppy won't be when she's an adult. Knowing when to switch from puppy food to adult food matters to your pup's health. Different breeds have different needs, and in this case, size and timing matter. Some dogs should stick with puppy food longer than 12 months, while others should swap to adult food before the one-year mark.


Let's start with why it matters. Growing dogs have different health needs than those who have reached peak development.

Your squirmy, energetic puppy needs more protein and fat in her diet than a comparatively laid-back adult or senior pal.

The science of pet food diets is managed by state feed officials and the Food and Drug Administration by providing certain requirements for pet foods by life stage. If your pup gets too much or not enough vital nutrients, it can affect her growth and development patterns.

When to change your puppy's diet

The longtime standard has been to transition to adult dog food at around one year of age because it's assumed that's when dogs reach their adult size. However, this isn't always accurate. The lifespan and growth trajectories for our pups vary quite a bit. In fact, large and giant breeds take longer to finish growing than toy and small breeds. While one year is a safe bet, each breed is different. For mixed breeds, you might want to consult your veterinarian to determine your dog's ideal adult weight and when to transition to adult food.

Toy and small-sized dogs

At less than 25 pounds, toy and small breeds reach full size faster than larger breeds, so their diets might need to change before the dog's first birthday. If your little dog has reached her expected adult size by the time she's eight months old, it's a good idea to go ahead and switch her food.


An adult diet formulated for toy and small breeds is your best choice to ensure your tiny pup gets the proper balance of nutrients.

Medium-sized dogs

Medium size breeds that top out around 50 pounds in adulthood. A dog that's closer to 30 pounds may be full-grown at 12 months, but if your dog is in the 45 to 50 pound range, she can continue growing until around 14 months.


Mid-sized dogs don't usually need a special size-related diet. Once your pal is fully developed, regular adult maintenance food is perfect for her.

Large and giant breeds

Large breed adults weigh between 50 and 80 pounds, and giant breed describes those over 80 pounds. Both of these heavyweight-class dogs can keep growing until 18 months. Generally speaking, the larger the breed, the longer it takes to grow to full size.


Large breeds do well on regular adult maintenance food, but specially formulated diets are important for giant breeds. These outsized pups need significant amounts of protein but a lower fat content so they don't turn into couch potatoes.

Switch to adult food gradually

Once you've determined when to switch from puppy food to adult food, the next step is planning how to make the change. It might be tempting to present your dog with her new food one day, but that's asking for trouble. Sudden diet changes, even within the same brand of food, can cause severe gastrointestinal issues. The best way to avoid nausea, vomiting, diarrhea, and decreased appetite is to swap her food gradually.


Begin by replacing a portion of her puppy food with adult food. Do this for a few days to let your dog's system get used to the new stuff. If that goes well, increase the ratio, and within a few days, your dog should be fully transitioned to adult food.


During and even after the changeover, watch for any signs that the new food makes your pup feel unwell. If so, adjust the ratio of puppy to adult food until her system settles down.

Keep tabs on your dog's physical appearance

It's important to monitor the condition of your dog's body, both during and after a change in her diet. Ashley Gallagher, Doctor of Veterinary Medicine, recommends working closely with your veterinarian to assess your pup's body condition score.


A dog's midsection should have a slight hourglass shape, with ribs palpable beneath her fur, fat, and muscle — not necessarily visible and definitely not protruding. Full-grown dogs should have a waistline that tapers from the rib cage to the hips, though it's more pronounced in some breeds than others.


By factoring in your best friend's breed or size, you can better plan when to switch from puppy food to adult food. As she grows into adulthood, keep her diet and health top of mind. If you notice weight loss or other changes in her physical appearance, consult your veterinarian. Your vet is an invaluable resource in navigating your dog's health journey.

Posted On: Aug 08, 22