Nutrients are substances that promote growth, provide energy, and help the body perform metabolic functions, such as maintaining and synthesizing tissues and regulating temperature. The nutrients a dog needs to maintain life and health are protein, carbohydrates, fats, vitamins, minerals, and water. These nutrients are found in meats, grains, fruits, and vegetables. A balanced diet supplies all the nutrients a dog needs.
Proteins are the building blocks of enzymes and hormones. The body uses proteins to create protective and structural tissues, such as skin, hair, nails, cartilage, ligaments, and tendons. Proteins carry oxygen and iron to the tissues and form the antibodies the immune system uses to fight disease.
The units that make up proteins are called amino acids. They are important in tissue growth and repair. Without amino acids, your Lab's body couldn't function. These multifunctional units can be used directly for energy or stored as fat or glycogen for later use as energy.
Providing high-quality nutrients in the correct amounts is one of the best ways to ensure that a puppy leads a long and healthy life. Each nutrient plays a pivotal role in the way the body functions.
Sources of protein are meat, grains, or a combination of the two. Common meat proteins you might see listed on a dog food label are beef, chicken meal, and meat by-products. The quality of animal protein varies, ranging from poor to excellent. For instance, the protein quality of chicken depends on whether the food contains chicken meat and skin, or chicken feathers, bones, heads, and feet. Bones and feathers are made up of collagen, a protein that isn't easily digested, so they aren't a good source of protein.
Nutritional deficiencies in dogs can manifest themselves in all kinds of ways, including chronic ear infections, loose stools, scratching, a dull coat, or dry, flaky skin.
The protein quality of grain doesn't vary as much as that of meat. Grain proteins aren't as good as high-quality sources of animal protein, but they're better than low-quality sources of animal protein. Plant protein ingredients include corn gluten meal, ground whole brown rice, and soybean meal.
Fats, also known as lipids, provide energy and make food taste good. Fat pads vital organs, protecting them from injury, and serves as insulation, helping the body conserve heat. Among other things, the body uses fats to help transmit nerve impulses and transport nutrients. The essential fatty acids in fats contain the fat-soluble vitamins A, D, E, and K. All are essential for a number of bodily functions, such as gastric acid secretion, inflammation control, and muscle contraction.
Animal fats and vegetable oils are the sources of fat in dog foods. If a single type of fat is used in a food — chicken fat, for example — it must be described that way on the ingredient label. Otherwise, you'll see the general term “animal fat.”
Besides providing the most concentrated form of energy of all the nutrients, fat is also highly digestible. Despite these advantages, high-fat foods taste so good that dogs — especially Labs — are likely to eat too much of them. That's why it's important to use portion control.
Carbohydrates are a plant-based source of energy that fuel the Lab to run and retrieve for hours on end. When it needs energy, the body uses carbs first so that protein can be spared for other uses, such as tissue repair and growth. In addition to serving as an energy source, carbohydrates help form the nonessential amino acids produced by the dog's body. When joined with proteins or fats, carbs play a role in the construction of body tissues. Without carbohydrates, the body couldn't synthesize DNA, RNA, or other essential body compounds.
Carbohydrates can take three forms: simple sugars, such as glucose; complex sugars, such as lactose and sucrose; and polysaccharides, such as glycogen and dietary fiber. Sugars provide energy for tissues and are essential to the functioning of the central nervous system. Glycogen, which is stored in muscle and the liver, provides emergency energy for the heart and cells. Fiber helps stimulate bowel movements and speeds waste through the system.
Grains, such as corn, oats, rice, and wheat are the primary sources of carbohydrates in dog foods. They provide the body with complex carbohydrates in the form of starch. Other plant sources, such as beet pulp and rice or wheat bran, provide fiber.
Although we may not think of it as such, water is the most important nutrient in a dog's diet. Water, which comprises almost 60 percent of an adult dog's body and 75 to 80 percent of a puppy's body, plays a vital role in cell and organ function. It helps maintain body temperature, aids in digestion and circulation, transports nutrients, lubricates body tissues, and facilitates elimination of waste. Dogs can go for weeks without food, but without water they can die within days.
A number of factors control water intake: thirst, hunger, metabolic activity (such as growth or pregnancy), and environmental conditions (such as temperature and humidity). The amount of water your Lab drinks and loses each day varies depending on the amount of food he eats. That's why it's important to make sure he has an ample supply of fresh water every day. Dogs that eat canned food, which is about 75 percent water, tend to drink less water than dogs that eat kibble (dry food).
Vitamins and Minerals
In minute amounts, these organic molecules serve a vital function in many of the body's metabolic processes. Vitamins are classified in two groups: fat-soluble and water-soluble. Fat-soluble vitamins — A, D, E, and K — can be stored in the liver, while water-soluble vitamins are excreted in the urine if the body doesn't use them. Among the vitamins you might see listed on a dog-food label are thiamin, riboflavin, niacin, pyridoxine, panthothenic acid, biotin, folic acid, and choline.
With a few exceptions, most vitamins can't be synthesized by the body and must be supplied in a dog's food. Vitamin C is one of those exceptions. Dogs can synthesize the necessary levels of vitamin C, so they don't need it added to their diet.
Because fat-soluble vitamins are stored primarily in the liver, they can quickly reach toxic levels if dogs are supplemented with them too frequently.
Like vitamins, minerals are present in your Lab's body only in tiny amounts, but they too are essential for life. Among other functions, minerals provide skeletal support and play a role in nerve transmission and muscle contractions. Macrominerals, which include calcium, phosphorus, and magnesium, account for most of the body's mineral content. Microminerals, also called trace elements, are present in the body in very small amounts. Microminerals include zinc, manganese, iodine, and selenium.
Proper vitamin and mineral balance is essential, but that doesn't mean you should automatically supplement your Lab's diet. Especially during puppyhood, an overdose of certain vitamins and minerals can cause problems in musculoskeletal development. The level of vitamins and minerals in a dog food should be considered in relation to other components of the diet. The goal is an overall balanced diet.