Choosing a food for your dog can be daunting with a vast choice available. We want our dogs to enjoy their food and be healthy. Canine nutrition is an exciting and rapidly science providing us with simple principles to help us choose. 

A dog needs a balance of protein, fat, carbohydrate, vitamins and minerals in their diet. Although (mostly!) carnivorous wolves and domestic dogs share a common ancestor, modern dogs are no longer identical to wolves. Living with humans and sharing food for around 14,000 years means that dogs are well-adapted to an omnivorous diet. 

Dog food needs to be complete, in that it provides all the nutrients that the dog needs, and balanced, containing the correct quantities of these nutrients for good health. Incomplete or unbalanced diets cause severe health problems. Commercially prepared diets approved by the PFMA (Pet Food Manufacturers Association) are rigorously tested to ensure they both are balanced and complete. 

Several factors affect the best diet choice for your dog. These include age or life stage, breed, activity levels and health. 


The early years

Puppies grow rapidly in their early years. Small dogs may be mature by one year, but large and giant breed dogs continue growing for the first two years. Calorie demand is increased in this growth phase, a high calorie, highly digestible food is required. A correct calcium/phosphorus balance is essential to grow a healthy skeleton. An incorrect calcium phosphate ratio can cause fractures, abnormal bone and joint formation and hormonal disease. A balanced, complete puppy food is essential for good health in this life stage.

Adult dogs

As dogs finish growing their calorie requirement reduces. Puppy food is no longer suitable as they will gain too much weight. Often a dog is neutered around this time, reducing calorie demand further. Dietary change should always be undertaken slowly, mixing rations to reduce gastrointestinal upset. 

Choose a complete, balanced food which your dog enjoys and monitor their weight. Weighing your dog is useful but can be tricky. Body condition scoring is often more useful. This involves checking how much fat covers their ribs and waist. Obesity is common in pet dogs and predisposes them to health problems like diabetes and joint disease. Conversely, if your dog is losing weight, he or she may need a more calorie-dense food. 

The senior years

Dogs age at different rates, small dogs tend to live longer than giant breeds. This variation means that your dog can be defined as senior from 7-12 years depending on their breed.

Dogs may become less active as they age. As their metabolic rate falls, they need a lower calorie senior food. Other old dogs lose their appetite or muscle bulk. Higher calorie senior diets are more palatable and help to counter muscle loss. All senior diets are highly digestible with good quality protein sources to reduce the work of metabolism for ageing organs. 

Regular veterinary checks and blood tests can be used to assess kidney and liver function in senior dogs. Disease in these organs affects the dog’s ability to process their food. Dental disease may make wet food more suitable for these dogs. Wet food formulations can also be more tempting if older dogs lose their appetites. 

Senior diets may contain helpful nutraceuticals. These are supplements, such as fatty acids for skin and coat health, to aid joint health and reduce cognitive dysfunction. 

Pregnancy and lactation

Female dogs need more calories in the last month of pregnancy and during lactation.. She may lose her appetite as birth approaches, so food needs to be calorie dense and palatable. Puppy food is ideal as it also contains more calcium aiding bone growth in the pups. It is not ideal to supplement large doses of extra calcium during pregnancy as this can cause illness (due to calcium imbalances) after the puppies are born.


Pet food can be formulated to treat and manage disease. For example, when a dog has kidney compromise restricting phosphorus and providing highly digestible protein will slow the progression of disease. Similarly, dogs with diabetes, liver disease and inflammatory bowel disease will benefit from specific diets. Your vet can give you relevant dietary advice. 


Smaller breeds have a higher metabolic rate than large dog breeds. Large and giant breeds need a lot of food, but small dogs need up to twice as many calories per kilogram. Small puppies, particularly toy breeds, need to eat little and often as they have small stomachs and can even develop low blood sugar (hypoglycaemia). This can cause weakness, seizures and coma. Most puppies need to be fed 3-4 times daily until they are 12 weeks old, but toy breeds may need 4-6 meals per day. Some dog foods are available in small breed formulations with smaller kibble. 

Large and giant breeds particularly benefit from specially formulated puppy foods as they grow quickly. As adults they may need a large volume of food so splitting their ration into two meals is ideal. Slowing down their eating may be necessary to stop them developing bloat. Exercise should be avoided around meal-times as the large volume of food can cause distension and even twisting of their stomach. 

Activity levels 

Working dogs and dogs involved in sports have a higher energy demand than most pets. They need more calories and may benefit from a working dog food formulation. A good quality food provides protein to build muscle and slow-release carbohydrates for energy. 

The factors above can help you find a food that suits your dog. Using a dry or wet formulation is usually a matter of personal preference. Dry food formulations help reduce plaque formation, but teeth cleaning is still necessary. Wet formulations contain more water so can be more useful in dogs with urinary disease. Familiarising a puppy with both wet and dry food helps with food transitions later in life. 

Feeding charts are supplied with most commercially prepared foods. Use these as a guide but monitor your dog’s weight or body condition score to find the correct amount for your dog. 

Applying these principles can help you find the right food for your dog. Good luck!

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