Nutrients are divided into subcategories: protein, carbohydrates, fats, vitamins and minerals, and water. Regular brushing and professional cleaning can keep your dog’s teeth healthy and gleaming. Giving your pet appropriate toys to chew prevents fractures.
Common dog food protein sources include meat, poultry, fish, and some plant ingredients, such as corn gluten and soybean meal.
Protein is best known for supplying amino acids to build hair, skin, nails, muscles, tendons, ligaments, and cartilage. It also plays a main role in hormone production.
Dogs, best fed as carnivores, require essential amino acids that are not all found in the proper balance in single plant protein sources such as soybean meal.
Common carbohydrate sources are plants and grains. Carbohydrates, also categorized as starches (sugars) and fibers, provide energy and bulk, respectively.
Starches are made up of various types of sugar, such as glucose or fructose. Through digestion, dogs can easily convert sugar into usable energy.
Fiber may or may not be fermented or broken down into short-chain fatty acids by bacteria in a dog’s intestines. Highly fermentable fiber sources, such as vegetable gums, provide high amounts of short-chain fatty acids. Moderately fermentable fibers, such as beet pulp, provide short-chain fatty acids and bulk for moving waste. Slightly fermentable fibers, such as cellulose, provide mainly bulk for moving waste through the digestive tract and only a few short-chain fatty acids.
Water is the single most important nutrient for the body. Without it, the body cannot transport nutrients, digest nutrients for energy, regulate temperature, or eliminate water.
Fats are found in meats, poultry, fish, and plant oils. Fat, for all its bad press, fulfills many vital body functions. Animal cell membranes are made of fat. Fat also helps maintain body temperature, control inflammation, and more. Fat is the primary form of stored energy in the body, providing twice as much energy as carbohydrates or proteins.
Fats also have been shown to be important in blood clotting and managing inflammation.
Vitamins are responsible for aiding functions such as bone growth, blood clotting, energy production, and oxidant protection. Vitamins A, D, E, and K require fat for absorption into the body, while vitamins such as the B-complex vitamins and vitamin C need water to be absorbed into the body.
Minerals provide skeletal support and aid in nerve transmission and muscle contractions.
Does your mature dog sniff at his bowl and walk away instead of digging in? You may think he’s just being picky, but it’s important to keep an eye on how much he’s eating — especially if he’s a senior. While age-related diminishment of the senses of smell and taste may account for some of his disinterest in food, appetite loss can also indicate a serious medical problem.
“It’s important to give your dog enough calories because weight loss can be debilitating to senior pets,” says Wendy Brooks, D.V.M., who warns that a loss in appetite should be mentioned to your vet. A good rule of thumb: If your pet hasn’t eaten in a day, make a visit to the vet. Here are six ways to entice your canine friend with a nourishing meal.

Many animals find canned food more palatable because they like the taste and texture, Brooks says. You can top their favorite dry food with room-temperature wet food.
Dogs like a warm or room-temperature (not hot or cold) meal. Avoid serving him day-old wet food from the refrigerator, and keep his food away from heat. Another reason he might not be eating: It's too hot outside.
Dogs prefer consistency when it comes to their food. Don't change every day, but try a new flavor, such as lamb or chicken, and see if he responds (it may trigger his sense of smell). To avoid an upset stomach, introduce a new food by mixing it with his old food in equal increments each day.
Common mature-dog health issues, such as arthritis or joint pain, can make it difficult for him to access his bowls. Keep food and water where he spends most of his time. Put a water bowl on all floors of the house, too.
Older pets are at a higher risk of dehydration. Provide a clean bowl with fresh water at all times. It will help prevent disease, such as a kidney condition, and aid in digestion.
Dogs are people pleasers. If you see him eating, give him a little verbal reward. He'll know it makes you happy and will repeat the behavior.