Canine Nutrition

As pet owners, we’re increasingly aware nutrition is a cornerstone of health. But, when it comes to building a healthy diet, there’s a mind-boggling number of products to choose from. So, what do you need to know about your dog’s dietary requirements to make informed choices—and make sure only the best is going into their bowl?

What Nutrients Do Dogs Need?

Your dog’s essential dietary nutrients can be split into six categories: protein, fat, carbohydrates, vitamins, minerals, and water. Let’s take a look at each of these in more detail:

1. Protein

Protein is vital for forming and maintaining tissues, such as cartilage and tendons[1]. Protein also plays essential roles in muscle, skin, and blood formation, alongside many other biological functions[1]. They are broken down into amino acids during the digestive process, which are used as building blocks by the body. There are ten essential amino acids for dogs[1]:

• Arginine
• Histidine
• Isoleucine
• Leucine
• Lysine
• Methionine
• Phenylalanine
• Threonine
• Tryptophan
• Valine

A dog’s diet must provide all these essential amino acids, as your dog cannot make them themselves. They can be found in animal or plant proteins. However, generally speaking, higher-quality animal proteins are a better source of these amino acids than plant protein sources.

How Much Protein Does a Dog Need?

The amount of protein your dog needs in their diet will depend on their life stage, activity levels, and health status. The quality and digestibility of the proteins also impact the amount required. The minimum recommended protein level for commercial foods for adult dogs is 18-21g per 100g of dry matter, assuming crude protein digestibility of 80%[2].

Is a High-protein Diet Better For Dogs?

Rather than simply thinking about the quantity of protein in a diet, thinking about quality is far more critical. High-quality, digestible protein, in smaller amounts, is superior to high quantities of low-quality, poorly digestible protein. There are no nutritional benefits to feeding excessive amounts of protein to your dog, and it may even be detrimental to their health[3].

Can I Feed My Dog a Low-protein Diet?

There are very few instances where a truly low-protein diet or even protein restriction is advisable for dogs—unless they have certain medical conditions, such as significant liver or kidney disease[3,4], and even then it must be undertaken cautiously. Failing to meet your dog’s dietary protein requirements can lead to significant health issues. So, don’t restrict your dog’s protein intake without guidance from your veterinarian. If you’re considering a vegetarian or vegan diet, please also seek advice from a board-certified nutritionist to ensure it’s not deficient in essential nutrients[5].

Can Dogs Be Allergic to Certain Proteins?

Allergies in dogs are most commonly a result of environmental allergens[6] or parasite infections[7], but dietary allergies are possible. Proteins are the most common culprit, rather than grains or other carbohydrates[8]. Some related conditions, including chronic enteropathy (chronic gastrointestinal disease), may be managed by switching to a novel protein diet[8]

2. Fat

Fat has a bad reputation. But it’s a vital source of energy and plays an essential role in the absorption of fat-soluble vitamins. Dietary fat is the most energy-dense form of nutrition, and is necessary when more calories are needed. Fats are also vital for producing essential fatty acids, maintaining skin and coat quality and modulating inflammatory responses[9]. They can also slow stomach emptying, which can help your dog feel fuller for longer. Excessive dietary fat, however, increases the risk of obesity. Some canine medical conditions, such as pancreatitis, may benefit from a fat-restricted diet[10].

3. Carbohydrates

Carbohydrates include digestible sugars, starch, and non-digestible fiber. In pet food, they mostly come from plant-based sources, such as grains, potatoes, tapioca, and legumes (peas, beans, etc.). While carbohydrates do not contain an essential source of nutrition that can’t be found elsewhere in your dog’s diet, your pet can use them to generate energy. Some carbs also have added benefits. For example, oats contain soluble fiber and linoleic acid, and sweet potatoes contain potassium and beta-carotene.

Carbohydrates can also provide an energy source when you need to restrict calories—or reduce fat or protein for medical reasons. Most dog foods will contain 30-60% carbohydrates[2]. Even at higher levels, if a diet is complete and balanced, carbohydrates are unlikely to be detrimental to your dog. If your dog is diabetic or has a genuine intolerance to a carbohydrate, however, individual dietary recommendations may be needed[11].

Another important carbohydrate consideration is fiber, both insoluble and soluble. Insoluble fibers—such as bran and cellulose—exit the body unchanged, increasing stool volume and frequency. Soluble fibers—such as guar gum or inulin—tend to dissolve, and can slow digestion and pull water into the gut. Fiber can also influence the digestion of fats and proteins in your dog’s diet[11,12]. Feeding a dog high-fiber food can be beneficial, but it’s essential to understand this difference in fiber types. This variation makes answering the question ‘how much fiber does my dog need?’ impossible without a better understanding of your individual pet.

4. Vitamins

Vitamins are organic compounds that are essential for normal growth and nutrition. They can be divided into fat- and water-soluble categories, and have many vital roles:

Fat-soluble Vitamins[13,14] Vitamin A: normal vision, immune system, and organ function, reproductive health Vitamin D: regulates the amount of calcium and phosphate in the body Vitamin E: antioxidant effects and immune system function Vitamin K: vital for normal blood clotting ability. Water-soluble Vitamins[13,14] Thiamin (B1): supports the body’s use of carbohydrates and is necessary for normal brain function Biotin (B7): supports the function of enzymes involved in metabolism Folic Acid (B9): crucial for the formation of DNA and red blood cells, as well as the utilization of various proteins Cobalamin (B12): intestinal health, nutrient absorption, DNA formation, nerve function, and red blood cell production Choline: supports liver function, and helps produce crucial chemicals in the brain.

Other critical dietary vitamins include riboflavin (B2), niacin (B3), pantothenic acid (B5), and pyridoxine (B6). Vitamin C is not a dietary essential for dogs, as they can create their own from glucose[2,13,14].

Consuming too many vitamins, however, can lead to toxicities. For this reason, you should never give your dog multivitamin supplements without checking if they are appropriate first. Some natural products, such as liver or lung, can also contain excessive amounts of certain vitamins, which, in large quantities, can lead to significant toxicities.

5. Minerals

Minerals are inorganic elements present in soil and water that are needed by your dog’s body to develop and function normally. They can be subcategorized into macrominerals (required in larger amounts) and trace minerals (needed in smaller amounts):

Macrominerals[13,14] Calcium: aids bone growth, blood clotting, nerve function, and muscle contraction Phosphorus: maintains cell membrane structure, generates energy, and helps form bones, teeth, and DNA Magnesium: plays a vital role in fuel production pathways Potassium: essential for nerve and muscle function Sodium: maintains cell structure, nerve and muscle function, and blood pressure Chloride: maintains fluid and acidity balance within the body. Trace Minerals[13,14] Iron: essential for oxygen transport in the blood Copper: utilized to produce red blood cells Zinc: has many roles, including enzyme, protein, immune system, and thyroid functions Manganese: helps many different enzymes in the body to function Selenium: supports immune system function Iodine: utilized in the production of thyroid hormone.

Other dietary minerals include chromium, fluorine, cobalt, molybdenum, and boron[1].

6. Water

While sometimes overlooked, hydration is crucial to your dog’s nutritional well-being. Your dog should always have fresh water available. Generally speaking, they’ll drink around 25-50ml/kg every 24 hours—maybe a little more if fed a dry kibble diet. Excessive thirst usually indicates a medical problem, and it is always advisable to speak to your veterinarian if your dog is drinking a lot.

What Can Impact My Dog’s Nutritional Requirements?

Life Stage

A growing puppy will have very different nutritional requirements from an elderly dog, who, in turn, will have different needs than an adult dog, or even a pregnant or lactating dog. If feeding a commercial diet, choose one targeted to your pet’s life stage.

Lifestyle

A working dog, or one that does competitive agility, will need significantly more calories daily than a dog that leads a more sedentary lifestyle.

Health and Disease

Diet can play a vital role in managing certain medical conditions, such as chronic gut disorders, pancreatic disease, and kidney disease. Therefore, different diets may be appropriate depending on your dog’s health status. If your dog has a medical condition requiring a dietary modification, your veterinarian will discuss the options.

Final Thoughts

Canine nutrition is a hugely complex topic, and there is no one-size-fits-all solution when it comes to the perfect diet. However, a complete, balanced diet is the cornerstone of health, and it’s widely recognized that our dogs are living longer and happier lives due to improved nutrition. So, it’s worth taking the time to understand your dog’s dietary needs in more detail, and making sure you have a good understanding of what goes into their bowl.