How Long Should I Feed My Dog Puppy Food?

Here’s when to make the switch to adult dog food.

puppy wearing graduation cap

You might want your puppy to stay a puppy forever, but eventually he has to grow up — and when he does, you’ll have to start feeding him adult dog food.

But when should you make the switch, and how do you do it?

The Dodo spoke to Dr. Sara Ochoa, a veterinarian consultant at Senior Tail Waggers, to find out how long to feed your dog puppy food and how to switch him to adult dog food properly.

When to switch a puppy to dog food

According to Dr. Ochoa, you should wait until your puppy’s fully grown to start feeding him adult dog food.

The age at which a puppy matures will depend on his size, so when you can start feeding dog food will vary for different pups. “This may be at 6 to 8 months for smaller dogs (25 pounds or less), 12 to 16 months for medium-sized dogs (25 to 75 pounds) and 2 years for large and giant-breed dogs (over 80 pounds),” Dr. Ochoa told The Dodo.

Here’s a breakdown of approximately when you can start feeding your puppy adult dog food:

  • Small dogs (25 pounds or less) — 6 to 8 months old
  • Medium dogs (25 to 75 pounds) — 12 to 16 months old
  • Large and giant-breed dogs (over 80 pounds) — 18 months to 2 years old

Your vet can also help you decide when to switch to adult dog food if you’re not totally sure.

What’s the difference between puppy and adult dog food?

You might think that puppy food and adult dog food are basically the same (it’s all dog food, right?), but they’re actually not — and you shouldn’t feed your puppy adult dog food before he’s ready.

“Adult food does not have the proper nutrients needed for a growing puppy,” Dr. Ochoa said. “Puppies need higher protein content, fats and minerals than adult dogs do.”

Adult dog food contains less protein and fat than puppy food since adult dogs don’t need as many nutrients to feed a growing body like puppies do. Since puppies are still developing, they burn a ton of calories and need a lot more protein, fat, calories and minerals in their food to keep them healthy.

“Puppies need protein and fats to keep up with their high-energy demands,” Dr. Ochoa said. “These puppies are quickly growing and have high energy levels that need more nutrients than older dogs.”

For example, the Association of American Feed Control Officials (AAFCO) recommends that puppy foods (food for growth and reproduction) contain a minimum of 22.5 percent protein, while adult dog foods (adult maintenance) only need to have 18 percent. The AAFCO also recommends that puppy foods contain a minimum of 8.5 percent fat and 1.2 percent calcium, while dog foods should have only a minimum of 5.5 percent fat and 0.5 percent calcium.

While puppy food is good for puppies, you shouldn’t keep feeding it to your dog once he’s fully grown since puppy foods have a lot of calories and fat. If you do, he could become overweight because his body isn’t using up as many nutrients as a young, hyper puppy.

“If adult dogs ate foods that were this high in protein and fats, they would quickly become overweight, which can lead to other health issues, such as heart disease and diabetes,” Dr. Ochoa said.

So the bottom line is that puppy food and adult dog food are formulated to have just the right amount of nutrients that your dog needs for each stage of life, and it’s not recommended to feed your pup food that’s not meant for his current life stage.

How to transition from puppy food to adult dog food

According to Dr. Ochoa, “When switching diets, it is best to make the transition slowly.”

Any time you transition your puppy (or adult dog) to a new food, you should do it gradually. This is because dogs have sensitive stomachs, and changing your dog’s diet too quickly can upset his stomach and lead to vomiting and diarrhea.

Dr. Ochoa recommends this schedule to switch your puppy to adult dog food or to a new food:

  • Days 1–3: Feed 25 percent new food and 75 percent old food
  • Days 4–6: Feed 50 percent new food and 50 percent old food
  • Days 7–9: Feed 75 percent new food and 25 percent old food
  • Day 10: Feed 100 percent new food

Try a month’s supply of this air-dried dog food from Sundays for $75

So be sure to switch your puppy to adult dog food when he’s fully grown and make the transition gradually so he can get used to the new food.

We independently pick all the products we recommend because we love them and think you will too. If you buy a product from a link on our site, we may earn a commission.