Dog Nutrition Across the Lifespan

Dog nutrition is so much more than a bowl of kibble two times a day. Your dog’s age, size, breed, and weight are just a few of the factors that affect what and when they eat.

If you’re wondering when to switch from puppy to dog food, how to transition dog food, or whether you should feed your dog twice a day, keep reading.

Are dogs carnivores or omnivores?

As you may know, carnivores eat only meat while omnivores eat both plants and meat. So… which category applies to dogs?

EXPERT TIP: If you’re a vegetarian or a vegan wondering if your dog can adopt a similar diet, the answer is yes. Many dogs with food allergies do well with vegetarian diets! However, generally speaking dogs tend to be at their best with at least some animal products in their diet.

Both descendents of the now-extinct gray wolf, domestic dogs and modern day wolves fall under the order of carnivora. Despite what the name suggests, not all animals under this order have the same nutrient requirements. In fact, not all of them are carnivores, either! Thanks to domestication, your dog is actually considered an omnivore because they no longer have to rely on meat for their essential nutrients.

Does this mean your dog will never need meat again? Not necessarily. Meat is an excellent, easily digestible protein source for pups.

Whether or not your dog plant-based, there are certain must-have nutrients. We’ll talk about those next.

Dog nutrition

Energy is not a nutrient, but it’s essential for zooming around the living room, Sunday strolls, and puppy play dates. Protein, carbohydrates, and fat all provide this precious resource.

Pumping up the protein

How much protein does a dog actually need?

We wish there was an easy answer for this, but it depends on where they’re at in life. During certain stages like puppyhood and at their reproductive peak, dogs need more nutrients like crude protein to support their high-energy needs.

Protein promotion can sometimes lead to the assumption that the higher the protein, the better, and while there isn’t much data to support a negative effect of a protein-heavy diet, remember: everything in moderation. Any protein that isn’t used (especially if it’s of a low digestibility) can become excess fat.

Cruising on carbohydrates

Thanks to diet culture, carbohydrates (CHO) tend to get a bad rap. Contrary to what you may have heard, CHO aren’t just filler—they’re a terrific source of energy that supports your dog’s health and nutrition.

Most pet foods contain complex carbohydrates; depending on the source, they offer fibre, antioxidants, essential fatty acids, vitamins, and minerals. The digestible CHO you’ll find in many of these foods are called a-link CHO. They include rice, potatoes, corn, barley, wheat, and tapioca. Of these, rice is the most digestible (which is why you’ll often see it recommended for gut upset and other tummy troubles). On the other hand, b-link CHO take longer to digest, but they also provide invaluable nutritional feedback for your dog.

How many carbs are too many? We often see CHO intolerance in animals consuming diets that contain more CHO than they can digest and absorb. As you may have guessed, this tolerance level depends on the dog. Dog allergies can also play a role, but it’s important to keep in mind that allergies aren’t exclusive to carbohydrates—they can be developed secondary to just about anything… even protein.

Should I put my dog on a grain-free diet? 

Lately there’s been a lot of media attention given to grain-free diets for dogs. Unfortunately, because the pet food industry is not well regulated, human food fads tend to become dog food fads without the nutritional science to back it up. 

Here’s why this is problematic: the FDA issued a warning about a potential link between grain-free pet foods and canine dilated cardiomyopathy (DCM). With DCM, the heart becomes enlarged and has a tough time pumping blood throughout the body, increasing the risk of heart failure. 

We don’t share this to cause a panic, but as a reminder to have a look at your dog’s food ingredient list and/or to book a chat with your vet about what formulation is best for your dog’s age, breed, and need. 

Functional fats

Fats are an excellent source of essential fatty acids. They help your dog’s fur shine, enhance food flavour, carry fat-soluble vitamins, and support high-energy activities. That’s a hard-working nutrient!

For optimal health, dogs require linoleic acid (an omega-6 fatty acid) and two omega-3 fatty acids: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA are a must as, like humans, dogs aren’t great at creating and converting them without the support of proper nutrition.

Unlike us, dogs aren’t likely to get heart disease from a high-fat diet, but if your dog is on the sedentary side or carries extra weight, it’s still a good idea to opt for a healthier alternative. After all, at 9 kcal/g, fat has more calories than protein (4 kcal/g), making it all too easy for dogs to consume more than they need. The result? More fat.

In some cases, a high-fat diet may be exactly what your dog needs. Your veterinarian may recommend this if your dog is a thin picky eater, as added fat means extra flavour. The same may be true for hunting or athletic breeds, or in cases where your dog needs some added support to reach their ideal body condition score.

Essential vitamins and minerals for dog nutrition

The list of vitamins and minerals dogs need for optimal nutrition is long and, if you’re not a nutritionist yourself, often overwhelming. Rather than try to put together a DIY diet, we recommend reaching out to your vet for guidance and investing in a food developed by or with a veterinary nutritionist.



  • Choline (supports healthy brain and liver function)
  • Vitamin A (important for growth and immunity)
  • B vitamins (helps with enzyme and protein function within the body)
  • Vitamin D (helps balance calcium and phosphorus for proper muscle and bone  maintenance)
  • Vitamin E (supports cell function and fat metabolism)
  • Calcium and phosphorus ratio (essential for muscle contractions, nerve impulses, and healthy bones and teeth, to name a few)
  • Sodium, potassium, and chloride (major electrolytes responsible for maintaining the acid-base and overall fluid balance in your dog’s body)
  • Copper and iron (helps form oxygen-carrying red blood cells and supports normal skin and fur pigmentation)
  • Zinc (necessary for a healthy immune system and to stimulate proper healing)

How to pick the best dog food for your dog’s nutrition 

We hear food-related questions from dog parents all the time:

  • When should I change my dog from puppy food?
  • Is it okay to feed an adult dog puppy food?
  • What should I be feeding my adult dog? 

The list goes on. 

Let’s start with selecting a diet. 

First things first: we always advocate for vet-recommended diets and reputable brands over most of what you’ll find in your run-of-the-mill pet store. There are hundreds (maybe thousands) of pet food options available, but not all dog diets are created equal. 

Neither the Canadian nor the American pet food industries are regulated for domestic sale. In the United States, the FDA does regulate the manufacture or dog food and treats, but there is no requirement for dog food products to obtain pre-market FDA approval. 

Bottom line: buyer beware.

Thankfully, we have the Association of American Feed Control Officials (AAFCO) to guide pet parents across North America. Made up of federal and state officials, veterinarians, scientists, and other experts, they offer peace of mind by setting standards for quality pet nutrition. However, because the program is voluntary not everyone will adhere or aspire to these standards when it comes to dog food, dog treats, and even dog supplements. 

So… what’s a responsible pet parent to do?

Talk to your veterinary team. Like you, they want your dog to be as happy and healthy as possible. 

Here are some general tips to get you going:

  • Consider your dog’s age. For example, when searching for the perfect puppy food, choose a diet that is specially formulated for growth or has AFFCO’s Growth and Reproduction stamp of approval. 
  • Where possible, steer clear of “all life stages” diets. While these aren’t inherently bad, they may fall short of your dog’s individual nutritional needs. 
  • When researching diets, find out whether the brand is AAFCO formulated or has been put through AAFCO feeding trials. Like we mentioned before, this isn’t a requirement for dog food manufacturers, but if a brand has gone to the lengths of meeting AAFCO standards you can feel more confident the food will be a fit. 

Transitioning dog food

Your dog’s nutritional needs will change over time, but is there a magic number or age when the time is right to make a transition from puppy food to adult food, or adult food to a senior diet?

Yes… sort of. 

When switching a puppy to dog food, you need to factor in how large they’ll be as adults. A Mastiff, for example, may stay on a puppy or adolescent diet (yes, that’s a thing) until they are around 18 months, but a Chihuahua or other small breed may outgrow a puppy diet by the time they reach 10 months. Bigger breeds tend to grow slow; staying on specialized development formulas for longer allows for proper muscle, bone, and growth plate formation.

If your adult dog is eating a quality, balanced diet, you may not need to switch to a senior diet unless or until your veterinarian recommends. However, in cases where diseases like arthritis, heart disease, or kidney disease are in the mix, a switch may be wise and recommended. If you’re ever unsure of when, how, or whether to make a switch, talk to your veterinary team—they’re there to support your dog’s nutrition every step of the way. 

Ready to make the switch? This infographic will help smooth the transition.

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