When Should You Switch From Puppy to Adult Dog Food?

Published Jan. 23, 2023

The transition from puppyhood to adulthood is an important milestone in any dog’s life—and any pet parent’s life as well.

Just a few months ago, your little ball of fluff was tumbling around, getting into mischief. Now that ball of fluff has grown up, and it’s time to consider the steps you need to take to ensure lifelong health for your pet.

Fundamental to a dog’s lifelong wellness is nutrition and feeding. One of the most crucial questions to ask is, “When is my puppy ready for adult dog food?”

The answer depends on a variety of factors, including your puppy’s breed, whether your puppy is spayed or neutered yet, and if there are any current or future health concerns you may have for them.

This article will help you determine when to switch your puppy from their puppy food to adult dog food, how puppy and adult dog foods differ, how to select the best adult dog food, and how to transition foods smoothly to ensure that your pup is set up for a life of good health.

What’s the Difference Between Puppy and Adult Dog Food?

The Association of American Feed Control Officials (AAFCO) is an organization that regulates the sale and distribution of animal foods.

According to AAFCO, puppy foods should be higher in protein, fat, calcium, and phosphorous than adult dog foods. These macronutrients and minerals help support lean muscle and bone growth. They also provide enough caloric density to enable the puppy to grow and perform basic bodily functions such as breathing, digestion, and movement.

Many puppy food manufacturers also include higher amounts of compounds like omega-3 fatty acids to support proper brain and eye development as your puppy ages. Large-breed puppies need specially formulated puppy foods that contain less fat, calcium, and phosphorous to moderate their rate of growth. This helps prevent skeletal diseases such as elbow and hip dysplasia that can result from growing too quickly.

For example, Hill's^® Science Diet Large Breed Puppy Food contains an optimal level of calcium for controlled bone growth, as well as high-quality protein to support growing muscles, an antioxidant blend to support a developing immune system, and DHA from fish oil to support healthy brain and eye development.

When to Switch to Adult Dog Food

Timing of a switch from puppy to adult dog food is crucial. You need to ensure that your puppy has the extra protein, fat, and minerals they need to support their growth and development and prevent various bone, joint, brain, and eye disorders.

Puppies will be ready for adult food when they reach about 80% of their adult size. But aside from breed size, you also need to consider whether they are spayed or neutered or if they are a highly active dog that needs more calories.

Breed Size

Because of their faster growth rate, smaller breeds such as Chihuahuas, Yorkshire Terriers, and Pugs reach adult size sooner than larger breeds such as Golden Retrievers, German Shepherds, and Dalmatians.

The guidelines below will help you to determine when to start feeding adult dog food:

Small breeds (under 25 pounds when fully grown) reach adult size at 10-12 months of age. These breeds will be ready for adult dog food at 9-10 months of age.

Medium-sized breeds such as English Springer Spaniels, Australian Shepherds, and Border Collies are 25-50 pounds when fully grown, and they reach adult size at 12-15 months of age. With growth rates between those of small breeds and large breeds, medium-sized dogs will be ready for adult dog food around 12-14 months of age.

Large breeds are over 50 pounds when fully grown. There are many large breed dogs, from the Boxer to the Great Dane, so the point at which these breeds reach mature size and weight can vary between 15 and 24 months of age.

With the wide range of breeds under this category and a generally slower rate of growth, these dogs will need to stay on puppy food until they are 14-24 months old to ensure they have enough protein and other nutrients during this stage. They also need to get those nutrients in the proper ratio to support the growth and proper development of their larger skeletons.

Activity Level

Athletic dogs may benefit from staying on puppy formulas longer, as the extra protein supports lean muscle growth and function, and the extra fat and higher caloric density can allow energy for high-intensity activities.

Spaying or Neutering

Breed size is not the only factor when determining when to transition your puppy to adult dog food. If your puppy has been spayed or neutered before they reach 80% of their mature size, their calorie requirement will drop noticeably following surgery, sometimes by up to 30%.

Because puppy foods contain a higher calorie density, feeding the correct amount during the remaining months of puppyhood is very important to prevent obesity as the puppy matures into an adult.

Spaying or neutering does not usually slow the growth rate of your puppy, but it may affect the growth plates in the bones of large breed puppies, setting them up for joint problems later in life. In addition, unspayed female dogs who will be bred early in life may need to stay on puppy food longer to support gestation and lactation following whelping.

Switching Too Early or Too Late

Because the timing of switching your puppy to adult dog food is so important, there can be negative consequences from both switching too late and switching too early.

Dogs that are taken off puppy food too late may be more predisposed to obesity and associated health problems later in life, given the fact that puppy formulas have more fat and calories per cup than adult dog formulas.

The extra protein and calories in puppy foods can also increase the rate of growth in certain dog breeds if they are not fed a breed-specific puppy food formula. If these breeds are left on puppy formulas too long, they can be more predisposed to developing joint problems in the future.

Similarly, if your puppy is taken off a puppy formula too early, they may suffer from nutritional deficiencies and growth abnormalities, failing to reach adult size around the expected time and increasing their risk of future bone, joint, brain, and eye issues.

How to Pick the Right Adult Dog Food

When it is time for your puppy to transition to adult dog food, how should you go about selecting the best adult formula for them as they become young adults?

The young adult stage is typically considered 1-4 years of age, as middle age starts by year 5-7 in many dog breeds. While most dogs are generally quite healthy during this stage in their lives, feeding them appropriately during their young adult years can help lower the risk of obesity, arthritis, and dental disease as they age.

Choosing a Brand

The many adult dog food companies are not all equal in terms of quality. The best first step is to feed a diet from one of the major dog food manufacturers whose guidelines meet AAFCO standards for complete and balanced nutrition, such as Hill’s, Purina, Iams, Royal Canin, or Eukanuba.

Dry Food vs. Wet Food

The next step is to decide whether you would like to feed your dog dry food, wet food, or a mixture of the two. Both types of food have positive and negative aspects, and the choice to use one, the other, or both depends on the specific needs of your dog.

For example, wet food:

Has a higher moisture content than dry food and may be better for dogs that do not drink much water.
Has a lower calorie density per volume than dry dog food, allowing dogs to feel fuller on fewer calories, which helps control their weight throughout their lives.
Is often more palatable and appetizing than dry food, so it may be a great option for picky eaters or for stimulating the appetite of dogs that are less interested in food.
Can be beneficial for dogs with oral abnormalities or dental disease, as it is easier for them to chew.

By contrast, dry food:

Can be a more economical option than wet food.
Is a great option for easier portion control and for dogs that tend to graze throughout the day rather than consume a full meal in one sitting, as dry food will not spoil as rapidly if left out for long periods of time.
Is beneficial for dental health, as the crunchy pieces act as an abrasive against the teeth during chewing and help prevent tartar buildup and thus tooth and gum disease.
Can be easily used as a tool in puzzle toys for enrichment and mental stimulation.
Is be used in slow feeders for reducing the rate at which dogs are able to consume their meals. When your pup eats more slowly, the risk is lower of them swallowing too much air and developing bloat, a potentially dangerous condition.

Nutritional Requirements

The final step in selecting the best adult dog food diet is to examine the Guaranteed Analysis panel on the bag or can of food and ensure that the formula meets a few major nutritional requirements.

Look for a food that has:

About 18% protein and 5.5% fat
Minerals such as calcium, phosphorus, potassium, sodium, chloride, magnesium, iron, copper, manganese, zinc, iodine, and selenium
Vitamins such as vitamin A, vitamin D, vitamin E, thiamine, riboflavin, pantothenic acid, niacin, pyridoxine, folic acid, vitamin B12, and choline

From there, you may decide to look for other ingredients that you wish to feed your dog:

Some adult dog formulas contain omega-3 fatty acids, which help support healthy skin and joints.
Other formulas have glucosamine for joint health or probiotics for gut health.
Some dogs are sensitive to chicken and do better on beef- or salmon-based formulas.

If you are unsure of the additional needs for your dog outside of the key ingredients and nutrients listed above, consult with your veterinarian.

Level of Activity

How you go about feeding your young dog will depend on their occupational status and whether they are spayed/neutered.

Working dogs and dogs that engage in agility work or endurance activities may require more calories and more fat (up to 10-20%) in their adult dog formulas. They can also make do with less fiber (around 5%) in their food.

On the other hand, most dogs kept as pets may be minimally active and can be fed the “standard” adult dog food diet as described above. They may also benefit from diets with at least 10% fiber on a dry matter basis. This will help ensure gut regularity with less physical activity.

Especially if they have been spayed or neutered, dogs with minimally active lifestyles can typically be fed 15-20% less than the amount recommended on the dog food label to avoid weight gain and its associated health issues.

Remember that dog treats and other sources of calories in the diet need to be included when determining the appropriate amount of food for your young adult dog.

How to Switch Your Puppy to Adult Dog Food

Once you have selected the best adult dog food for your puppy, you are ready to transition them slowly onto their new diet.

Because rapid diet changes can cause gastrointestinal upset in dogs, such as vomiting and diarrhea, it is recommended to introduce the new food slowly over a period of five days or so. Continue to feed your puppy as many times per day as they are used to throughout this process. The feeding schedule might look something like this:

Day 1: Mix some adult food with the puppy food at a ratio of 1:4, or 20% adult food and 80% puppy food.
Day 2: Increase the amount of adult food so your puppy is getting 40% adult food and 60% puppy food.
Day 3: Increase the amount of adult food again to 60% adult food, and decrease the amount of puppy food to 40%.
Day 4: Feed 80% adult food and 20% puppy food.
Day 5: Feed 100% adult food.

If your puppy develops vomiting, diarrhea, or lack of appetite, stop feeding the adult dog food and see your veterinarian.

How Often to Feed Your Dog

For large-breed puppies, it may be best for them to continue to eat three times per day.
For medium-breed puppies, they should continue to be fed twice daily when they have been transitioned to adult dog food.
For small-breed puppies, you may consider transitioning them to eating twice daily instead of three times per day after they are fully on adult dog food.

This may involve providing more attention and playtime for your dog as they become accustomed to fewer feedings per day. Consider extra walks, extra playtime, or brushing to distract them from feelings of hunger.

Some dogs may benefit from high-fiber adult dog food to increase feelings of fullness between meals. Your dog may also enjoy cleaned, raw fruits and vegetables such as sliced carrots, cucumbers, or apples without the core or seeds.

If you have any questions about transitioning your puppy to adult dog food, contact your veterinarian. In addition, a board-certified veterinary nutritionist can be a great resource for any issues that come up, and they can help develop the best diet and feeding schedule for your new family member.

Featured image: iStock.com/SolStock