Dogs need several different kinds of nutrients to survive: amino acids from proteins, fatty acids and carbohydrates, vitamins, minerals, and water. The tables in this article provide recommended daily allowances for dietary nutrients based on the minimum amount required to maintain good health in normal dogs. Your dog’s unique nutritional requirements will depend on its size, its breed, and its stage in life, among other factors. A better understanding of how dogs use the various nutrients in food and how much of them they need can help you choose a healthier diet for your pet.

PROTEINS AND AMINO ACIDS

Dogs cannot survive without protein in their diets. Dietary protein contains 10 specific amino acids that dogs cannot make on their own. Known as essential amino acids, they provide the building blocks for many important biologically active compounds and proteins. In addition, they donate the carbon chains needed to make glucose for energy. High-quality proteins have a good balance of all of the essential amino acids.

Studies show that dogs can tell when their food lacks a single amino acid and will avoid such a meal. Dogs are known to selectively choose foods that are high in protein. Whether this is simply a matter of taste or a complex response to their biological needs for all 10 essential amino acids is not known. However, dogs can survive on a vegetarian diet as long as it contains sufficient protein and is supplemented with vitamin D.

FATS AND FATTYACIDS

Dietary fats, mainly derived from animal fats and the seed oils of various plants, provide the most concentrated source of energy in the diet. They supply essential fatty acids that cannot be synthesized in the body and serve as carriers for important fat-soluble vitamins. Fatty acids play a role in cell structure and function. Food fats tend to enhance the taste and texture of the dog’s food as well.

Essential fatty acids are necessary to keep your dog’s skin and coat healthy. Puppies fed ultralow-fat diets develop dry, coarse hair and skin lesions that become increasingly vulnerable to infections. Deficiencies in the so-called “omega-3” family of essential fatty acids may be associated with vision problems and impaired learning ability. Another family of essential fatty acids called “omega-6” has been shown to have important physiologic effects in the body.

ENERGY NEEDS

Dogs need a certain amount of energy to sustain the normal activities of their daily lives. Growth, pregnancy, lactation, and exercise all increase these normal energy requirements. Generally measured in terms of calories, energy comes from three major dietary components: carbohydrates, protein, and fats.

Omnivorous animals get some of their energy from carbohydrates, which include sugars, starches, and dietary fibres’. The major sources of carbohydrates in commercial dog foods are cereals, legumes, and other plant foodstuffs. So-called absorbable carbohydrates, including glucose and fructose, can be directly absorbed and do not need to be digested by enzymes. Digestible carbohydrates are readily broken down by intestinal tract enzymes. Fermentable carbohydrates include certain starches and dietary fibres that pass undigested through the small intestine to the colon, where they are fermented by microbes into short-chain fatty acids and gases. Some studies suggest that fermentable fibres’ may aid in the regulation of blood glucose concentrations and enhance immune function.

Non-fermentable fibres, such as cellulose and wheat bran, contribute little in terms of energy or nutrition and are primarily used to decrease caloric intake of the overweight animal.

ENERGY NEEDS OF GROWING PUPPIES

The growing puppy starts out needing about twice as many calories per pound of body weight as an adult dog of the same breed. Owners should start feeding puppies food at approximately 4 weeks after birth, because mother’s milk is no longer sufficient. Food is best offered to puppies in multiple, well-spaced meals.

ENERGY NEEDS OF OLDER DOGS

Because of decreased physical activity and slowed metabolism, older dogs need 20% fewer total calories than do middle-aged adult dogs. As dogs age, they tend to become overweight. It may take obese dogs longer for their blood glucose concentrations to return to normal. This disrupted carbohydrate metabolism can lead to diabetes.

ENERGY NEEDS OF LACTATING DOGS

New mothers generally suckle their puppies for at least 6 weeks. The mother’s need for calories increase with the number of puppies and the week of lactation, up to 4 weeks. Giant breeds (like Great Danes) have proportionately smaller digestive tracts and may not be able to eat enough to sustain themselves during lactation. Owners of such dogs may need to start feeding puppies’ supplemental food at an early age.

MINERALS

Twelve minerals in the table are known to be essential nutrients for dogs. Calcium and phosphorus are crucial to strong bones and teeth. Dogs need magnesium, potassium, and sodium for nerve impulse transmission, muscle contraction, and cell signalling. Many minerals that are present only in minute amounts in the body, including selenium, copper, and molybdenum, act as helpers in a wide variety of enzymatic reactions.

Dogs can get too much or too little of a specific mineral in their diets. A deficiency of dietary calcium, for instance, causes a condition known as secondary hyperparathyroidism. Recognized clinically for many years in dogs fed meals consisting mainly of meat, this disease results in major bone loss, skeletal abnormalities, and pathological fractures. An excess of calcium, on the other hand, may also cause skeletal abnormalities, especially in growing large-breed puppies.

UNDERWEIGHT OR OVERWEIGHT?

Underweight

• Your dog is not getting enough to eat if you can easily see its ribs, vertebrae, and pelvic bones, feel no fat on the bones, and possibly notice some loss of muscle mass. If chronically underfed, adult dogs may experience impaired ability to nurse young and perform work, and increased susceptibility to bacterial infections and parasites; puppies may be stunted in their growth; adult dogs may develop osteoporosis.

 Ideal

• Your dog is at an ideal weight if you can easily feel its ribs. The waist should be easily observed behind the ribs when viewed from above. An abdominal tuck is evident when viewed from the side.

Overweight

• Your dog is overweight if you cannot feel its ribs, see fat deposits over its back and the base of its tail, discern no waist behind the ribs when viewed from above, and see no abdominal tuck in profile. Obesity occurs in one out of four dogs in western societies. Its incidence increases with age and is more common in neutered animals. Health risks include diabetes and osteoarthritis.

FEEDING PRACTICES

Q: Does my dog need to eat meat?

A: Because dogs are descended from omnivores, they are not strict meat eaters. They are remarkably adaptable to a wide range of ingredients, texture, and form in terms of what they will eat. Though many dogs may prefer animal-based protein, they can thrive on a vegetarian diet. Regardless of whether the protein comes from plant or animal sources, normal adult dogs should get at least 10% of their total calories from protein. Older dogs appear to require somewhat more protein to maintain their protein reserves, perhaps as much as 50% more.

Q: How much fibre is good for my dog?

A: Fibre in the diet is probably good for overall gastrointestinal health and may help some dogs keep their weight down. The typical diet of normal adult dogs contains between 2.5 and 4.5% fibre. However, the fibre content of some “diet” dog foods may be higher. This may allow the dog to feel full without consuming too many calories for effective weight control. Diets high in fibre also may help in the management of hyperglycaemia (high blood sugar), and may improve large intestine function.

On the other hand, too much fibre in the diet can decrease the digestibility of other important nutrients and result in loose stools, frequent defecation, and reduced palatability of the dog food. Wheat bran and barley products are high in fibre.

Conversely, dog food ingredients high in starch, including rice and dried potatoes, have less fibre.

Q: How often should I feed my dog?

A: Dogs eat larger, less frequent meals than do cats. It is fine to feed adult dog one or two times per day. Puppies, however, need two to three daily meals.

Q: How can I help my overweight dog trim down?

A: The most obvious answer is to feed your dog smaller amounts on the same feeding schedule. Some dog owners offer less tasty food or allow less time to eat. Another option is to feed your dog one of the low-calorie dog foods on the market.

It’s also important to remember to keep your dog from sampling the dog-next-door’s food and to refrain from giving your dog table scraps.

Q: How do heat and exercise affect the amount of water my dog needs?

A: Fresh water should be available to your dog at all times to reduce the risk of becoming overheated. A dog’s need for water increases in keeping with the amount of energy he expends during exercise, and this need may more than double in warm conditions. Ideally, you should actively offer your dog water during exercise.

FOOD CHOICES

Commercial dog foods come in a variety of forms.

The most common types are dry, semi-moist, and canned. The moisture content of these foods ranges from 6 to 10 % for dry, 15 to 30% for semi-moist and 75% for canned. Most canned food has relatively more fat and protein and fewer carbohydrates than does dry and semi-moist food, and generally contains much higher levels of animal products.

Pet food labels must list the percentage of protein, fat, fibre, and water in the food. When reading labels, it is important to remember that what may appear to be a big difference in the amount of a nutrient— for example, 8% protein in a canned dog food vs. 27% protein in a dry dog food—reflects the fact that there is more water in the canned food.

PET FOOD ADDITIVES

Some other substances that might be found in pet foods, which are not required nutrients, are described below:

• Chondroprotective agents are used by the body to make cartilage and joint tissues. Although, use of chondroprotective agents may be indicated for selected clinical conditions, widespread inclusion in the diets of healthy populations may not be warranted at this time.

• Antioxidants work to prevent oxidative damage to nutrients and other compounds in the body and inhibit or quench the formation of free radicals. At this time, data are lacking to make specific recommendations beyond those for the essential vitamins and minerals that are components of antioxidants.

• Herbs and botanicals are used in pet foods either to provide flavour or, more often, to have a medicinal effect on the body. This is especially true in the case of extracts, where the classical nutritive components of the plant may be separated from the extract in the process. Because the intended functions are more pharmacologic versus nutritional in nature, discussion of potential benefit is beyond the scope of this publication. Flavours and extracts derived from animal tissues such as poultry or fish are considered “natural” flavours. A wide variety of flavours can be derived from other animal and plant materials, including dairy products, eggs, herbs, and spices. Acceptable processing methods include roasting, extraction, and fermentation. Except for artificial smoke and bacon flavours, synthetic substances are rarely used in most dog and cat foods.

• Colours are synthetic compounds used to replace or accentuate the inherent colour of the food. Only certified colours approved for use in human foods are allowed in pet foods. Iron oxide is a synthetic but noncertified colour that can be used at levels not to exceed 0.25% of the pet food product to give dog and cat food a red, meaty appearance.

• Titanium dioxide is another common colour additive in human and pet foods because it can induce“brightness” in foods by complementing other colour additives. Its use is limited to 1% of the food by weight.

VITAMINS

Vitamins are organic compounds that take part in a wide range of metabolic activities. Dogs require vitamins in their food, albeit at low concentrations.

First noticed in dogs some 75 years ago, vitamin deficiencies can cause a variety of health problems. Clinical signs of vitamin A deficiency, one of the first deficiencies studied in dogs, include motor and vision impairment, skin lesions, respiratory ailments, and increased susceptibility to infections. Dogs fed diets lacking vitamin E show signs of skeletal muscle breakdown, reproductive failure, and retinal degeneration. Thiamine deficiency can lead to brain lesions and other neurological abnormalities if the deprivation is sudden and to heart damage and death if it is chronic. Some vitamins, such as vitamin D, are not only essential in small doses, but also toxic in excess amounts.

Article from The National Research Councle of The National Academies