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What’s the Difference Between Puppy Food and Adult Dog Food? (And Senior Food Too!)

Different aged dogs will need different foods. We clear up the distinction between these foods formulated for dogs at various stages of life.

We all want what is best for our dogs, whether they are a newborn puppy or a senior citizen. Different aged dogs will need different types of foods to suit their needs.  Pet store shelves are full of a seemingly endless variety of dog food formulas targeted at specific life stages.  So what exactly is the difference between puppy food and adult dog food (and senior dog food)?

Different dog foods are formulated to address the nutritional requirements specific to the age of a dog, whether they be a puppy, an adult, or a senior.  The food’s volume, calorie content, macronutrient ratios, and texture are all designed to provide the proper nutrients necessary to keep your dog healthy at their specific stage of life. 

Let’s look at the main differences.

Puppy Food

When you get a puppy they are normally seven or eight weeks old. They are given away at this time because they have been weened off of their mother’s milk and are old enough to receive their vaccination shots. Puppies will have very small and sharp baby teeth at this age. 


Puppy food is naturally more calorie dense. This means that for the same volume of food, puppy food is more nutritious. Because puppies have small stomachs they need a highly nutritious food that doesn’t take up too much space in their baby stomachs.

As your puppy grows, their stomach will naturally grow as well. It is crucial that while their stomach grows, they are getting enough calories. Going from their nutrient dense mother’s milk to solid food sometimes means that they will struggle to eat a large volume of food. 


A puppy’s food will be high in protein. This is because protein is the nutrient that promotes growth and repair in all areas of the body. Without protein, their body would struggle to build muscle. Your puppy will naturally crave a protein rich food.

Look for puppy foods that list a source of protein as one of the first ingredients. Something you recognize like chicken, fish, or beef is ideal. One gram of protein is just 4 calories though, so make sure their food contains fat too, at 9 calories per gram.


Like protein, a puppy needs fat in their diet in order to grow. Fat is the most calorie dense nutrient and is useful in making the food more calorie dense. Fat will be provided by the meat or fish included in the ingredients.

Some puppy foods add extra fats known as DHAs that are also abundant in dog’s breast milk. Puppies benefit from this type fat, known as an omega fatty acids, because it help with joint growth and prevents chronic illness.

How To Pick A Puppy Dog Food

Look for puppy foods that have whole ingredients listed in the first three ingredients. On a product label, the ingredients are listed in order of predominance, with the ingredients used in the greatest amount first, followed in descending order by those in smaller amounts. Look for foods that don’t have a long list of chemicals and preservatives.

Likewise, don’t get your puppy a food that contains a lot of ‘filler’ such as corn, wheat, or soy. Dog food companies sometimes bulk out their food with these cheap ingredients. They are not necessarily bad for your dog, but there are other far better sources of food. 


When puppies begin teething — the painful period between three and four months when their adult teeth first begin to grow in — they may need a softer type of food. During this period you can mix wet canned food in with their crunchy dry food, or add warm water to the dry food. Both ways help to soften the kibble and not hurt their teeth.

If your puppy is still struggling with hard food because they are teething, you may need to feed them soft wet food for the time being. Make sure that the wet food is nutritious enough, as the extra water content will increase the volume and fill their stomachs quicker for less calories.


When you first get your puppy aged about 8 weeks, they will sleep a lot then wake up every few hours. Feeding them as often as they want is important as they will instinctively know when to eat. When your puppy is reaches their adult height it is time to consider adult food.

dog eats from bowl of food

Adult Dog Food

When your puppy is roughly 6 months old, they might need to switch to adult dog food. Depending on the breed of dog, some will need to switch faster, while some may take up to a year. 

Check with your veterinarian.  Often, a good time to make the switch is around the time you get them spayed or neutered as they then require less calories.


Adult dog food contains the same ingredients as puppy dog food but with more volume. This is because adult dog’s stomachs are far larger and if filled with the nutrient rich puppy food, may cause weight gain. It is important to watch out for weight gain in adult dogs as they can comfortably eat more food.


Just like puppies, adult dogs need a diet high in protein and fat. Dogs were domesticated from wolves, who eat a predominantly carnivorous diet consisting of prey they hunted. As dogs started to live alongside humans their diet changed to incorporate more carbohydrates and fiber.

Although dogs can survive on diets high in carbohydrates such as grains and cooked vegetables, they will be most healthy when predominantly eating sources of protein and fat. Look for recognizable sources of protein when choosing an adult dog food. 

Adult dog food also contains some supplementary fats such as Omega fatty acids. As your dog ages they can be prone to arthritis and other joint issues. Keeping your dog’s diet high in these fats will help them stay stronger for longer. Omega fatty acids are very high in most fish.


Pick a standard dog food that has wholesome ingredients listed in the first three ingredients. Because dogs are adults for longer than they are puppies or seniors, most dog foods are suited to adult dogs. They will be somewhat calorie dense but not as dense as puppy food.

Senior Dog Food

Senior dog food is designed for dogs that are reaching their senior years. The age you start to feed your dog senior dog food will depend on their breed. This is because some dogs on average live up to 18 years, while others live just eight years.

If you have a small dog such as a Jack Russell Terrier, their senior years may be around about 11 or 12 years old, as their lifespan is approximately 16 years. Your best bet is to find out the average lifespan of your dog’s breed or, if mixed breed, ones similar to it in size and appearance, and consider the last third or quarter to be their senior years.  

Again, consult with a vet to find out when a switch to senior dog food is best for your individual pet.  Specific health issues can sometimes prompt a vet to either accelerate or delay the switch to senior dog food.


The main difference between senior dog food and adult dog food is the higher amount of fiber found in senior food. As dogs age, their digestive systems slow down, meaning food moves slower through them. Because their organs are less efficient, it is important to help them out.

Food that contains more insoluble fiber will help your dog with constipation. These types of fibers actually don’t break down in the stomach and act as a lubricant for other digested food to be pushed through. Insoluble fibers are found in foods like corn and vegetables.

Fiber will also help keep your senior dog’s stomach bacteria healthy. If they become constipated, food can stay in their digestion for too long and lead to problems that involve an overgrowth of bacteria. It is very important to keep things moving smoothly as your pet gets older.

Nutrients To Volume Ratio

Senior dogs are far less energetic than puppies and adult dogs. They can spend up to 18 hours a day sleeping and will often struggle to go for walks as long as they used to. Because they move less, they require less energy from food.

Problems can arise with senior dogs who want to eat as much as when they were younger. Because their stomachs haven’t shrunk, they will easily eat the same amount as when they were more active. For this reason, senior dog food is less calorie dense for the same volume.

If your senior dog is gaining weight, even with the senior dog food, it might be worth adding warm water to their food. They will naturally ingest more water this way, filling up their stomachs quicker. This is also a good way to keep them hydrated, as older dogs can forget to drink water.

Final Thoughts

So to recap, the difference between puppy, adult, and senior dog food is what the food contains and for whom it is designed. Puppy food is calorie dense and has a lower volume. It also contains omega fatty acids to help with joint growth and development. 

Adult dog food is the standard dog food that will suit your dog for most of its life. It is balanced to accommodate for your adult dog’s needs. 

Senior dog food is higher in fiber and lower in calorie density. This is to prevent your senior dog from being constipated and to stop them from gaining weight as they move less.

When buying a dog food, make sure it suits your dogs age and preferences. If you are unsure, pet store staff or veterinarians can offer advice.

Superb Dog Editor

Superb Dog Editor