^ Knowing how much protein, carbohydrates, and fats your dog needs

^ Making sure that your dog is getting the right amount of vitamins and minerals

^ Getting an inside look at how your dog’s food is made

^ Checking out organic options

Dogs are carnivores — meat eaters. Their teeth are shaped for biting, tearing, and grinding flesh and bones, and their intestinal tracts are short, with enzymes that are good for digesting proteins (but not very good at breaking down and absorbing plant material). So it only makes sense that your dog’s diet should be meat based.

Dogs are also opportunists, which means they’ll eat whatever comes their way, including the trash in your kitchen and the grass in your yard. They do gain nutritional benefits from vegetables, fruits, and grains, but they need meat in their diets as their main source of nutrition.

This post covers the eight building blocks of nutrition. All these building blocks are required in a well-balanced diet, regardless of the dog. But the amounts of these nutritional elements that each dog needs depends on that dog’s unique situation — puppies and adults need different amounts, as do spayed and pregnant females, and active and inactive dogs.

Proteins

A brief history of dog food

Fats

Carbohydrates

Every cell in your dog’s body needs a continuous supply of carbohydrates, particularly in the form of glucose, to function properly. In fact, it is so important for cells to have glucose that the body produces the hormone insulin to drive glucose into the cells. Glucose is especially important for your dog’s brain and muscles. Carbohydrates also assist in the digestion of other nutrients, especially fats. Your dog’s carbohydrate requirements vary according to his level of activity, health, and overall energy needs.

Carbohydrates come in three basic forms: sugars, starches, and cellulose. Sugars and starches are simple carbohydrates because they are readily available as glucose or can be broken down into glucose. Good sources of simple carbohydrates are rice, oatmeal, corn, and wheat. Simple carbohydrates are easy for your dog to digest when properly cooked; they also add texture to the food, making it more palatable. Cellulose, the main carbohydrate found in the stems and leaves of plants, is a complex carbohydrate. Dogs don’t have the enzymes to digest cellulose (most animals don’t), but it serves as fiber, helping regulate water in the large intestine and aiding formation and elimination of feces.

The best foods use the carbohydrates that come in grains; sugar need not be added to food, although some manufacturers do this to make it taste better. The AAFCO has no recommended minimum or maximum levels of carbohydrates in dog foods. Carbs make up the remainder of the bulk of the food after fats, proteins, fiber, and vitamins and minerals have been added.

Fiber

Fiber is an important component of dog food. It provides bulk to the food and helps the intestinal contents absorb water, which results in formed stools that are readily expelled. If a food has too little fiber, the dog may have loose stools, because there is nothing to help the stools form. If a food has too much fiber, it will pass much more quickly through the gastrointestinal system, making digestion less efficient and the stools hard and compacted.

Beet pulp is an excellent source of fiber. It is the dried residue from sugar beets, which first have been cleaned and freed of crowns, leaves, and sand, and then used to extract sugar for human foods. Dried tomato pomace is another good source of fiber. It is the dried mixture of tomato skins, pulp, and crushed seeds, a byproduct of the manufacture of tomato products.

Most dog foods contain between 3 and 6 percent fiber. Weight-reduction diets may have between 8 and 25 percent fiber.

Water

Water is the most plentiful molecule in your dog’s body (your dog’s body is two-thirds water) and is essential for every function, from digesting food to dashing across the yard. In the gastrointestinal tract, water dissolves nutrients to prepare them for digestion and helps transport the nutrients across the intestinal wall.

Your dog loses water by several routes, through salivation and respiration, and in urine and feces. If your dog loses more water than she takes in, she will suffer from dehydration, which, if severe and untreated, can be fatal.

Every dog should have access to clean, fresh water at all times.

Enzymes

Enzymes play a role, often in conjunction with vitamins, in just about every body reaction. They are like the keys that unlock the doors to chemical reactions. Each enzyme is the catalyst for one specific reaction, which is why so many different enzymes exist. The pancreas secretes several kinds of enzymes that assist in digestion. In addition to enzymes secreted by the pancreas, enzymes are present in fresh foods.

In most dogs, the pancreas produces sufficient enzymes for digestion. However, in some dogs, pancreatic function is not optimal. Older dogs frequently have trouble fully breaking down their foods for optimal absorption of nutrients, as do dogs with pancreatitis (inflammation of the pancreas) or pancreatic cancer.

Vitamins

Minerals

The Main Types of Dog Food

Reading a Dog Food Label

Figuring Out How Much to Feed Your Dog

How do you decide how much food to put in the bowl? If you’re just starting to feed a new food, and the label tells you how many calories the food contains, you may want to start with the information in Table Caloric Requirements of Dogs, which lists the calorie requirements of dogs depending on the dog’s weight and activity level. For the purposes of the table, an inactive dog is one who rarely gets more than a jaunt around the yard, a moderately active dog is one who gets 15 to 30 minutes of continuous exercise every day, and a highly active dog is one who gets at least several hours of exercise every day.

If the label doesn’t provide information on the caloric content of the food, you have to use the manufacturer’s recommendations as a starting point. Start by feeding 25 percent less than the manufacturer recommends and then increase or decrease the amount as necessary.

Table Caloric Requirements of Dogs

‘Figures represent the average number of calories required daily to maintain the dog’s weight.

The figures in Table Caloric Requirements of Dogs include treats and snacks.

As dogs exercise more, they need more calories to maintain their weight. But as dogs get larger, they require relatively fewer calories to maintain their weight. This is because larger dogs generally have slower metabolisms than smaller dogs. Age can affect caloric requirements, too. As a dog goes from 1 to 7 years of age, her energy requirements drop by an incredible 24 percent.

Dogs’ metabolisms vary so greatly that the best way to know exactly how many calories your dog needs each day is by trial and error. Feed the amount of food that will maintain your dog’s weight. If she loses weight, feed more. If she gains, feed less.

Choosing the Best Food for your Dog

How do you make that final decision? As a general rule, start by feeding a name-brand, good-quality, commercial balanced diet that has been tested by feeding trials in dogs. Put more trust in companies that have been around a while, because they have their own internal quality controls in addition to those imposed by the regulatory agencies.

Sorry, but the best-quality foods are not the cheapest. However, the reverse isn’t necessarily true: Paying a lot for your dog food doesn’t guarantee its quality. As you search for the best food, don’t hesitate to experiment. Be a good observer. Talk to your veterinarian and other dog people, such as your breeder. Over time, you will gather more information and be able to make better decisions based on fact as well as experience.

When you have selected a quality food for your furry friend, your job isn’t done. You still need to keep close track of your dog’s response to the food. Watch his body condition. Your canine companion should maintain a correct weight on his new food. If he gains some weight but looks and acts healthy and full of energy, it may be that the nutrients in the new food are more digestible than those of the previous food, so you don’t need to feed as much. If your dog loses weight on his new food, start looking for another. Your dog’s coat should grow and glisten on his new food, and his skin should be pink and supple, with no sores. A dog’s coat is often a reflection of his general health, although it isn’t the only monitor to use. For example, during the spring in temperate climates, most dogs’ coats look dry as they shed their heavy winter garb for a lighter spring coat.

One of the best criteria you can use to monitor your dog on a new food is to observe his stools. Stool quality is determined by the ingredients in the food, the relative amounts of different ingredients, the type and amount of fiber, and the digestibility of the ingredients. Small, firm stools indicate a food that is highly digestible. However, your dog should not be constipated or straining to defecate. Large stools, particularly if they are somewhat loose, may indicate a food with less digestible nutrients and/or a high fiber content. Your dog’s stools will vary from day to day. But if your dog often has small, hard stools, consider changing to another food. Those stools may be easy to pick up, but they may also mean that your dog is chronically constipated.

Monitor your dog’s attitude and energy level. If you feed your dog a good-quality food, he will have lots of get-up-and-go. He will have the energy and endurance to play all you want. Most of all, he will have that joy for life that we all appreciate in our canine companions.

What’s the best dog food for your dollar? Most people find that they save money by buying good-quality, premium foods for their dogs — the kind of food sold at pet supply stores rather than grocery stores. This is because dogs need to eat much less of a good-quality food to take in their required nutrients. In addition, dogs on high-quality foods probably have fewer health problems, and when they do, they heal faster. The icing on the cake is easier cleanup in the yard.

Paying Attention to How You Feed Your Dog

Organic Options for Feeding Your Dog

Maybe you’re going organic with your own diet. Or your dog suffers from allergies and you’ve heard organic food may help. Perhaps you just want your dog to eat as well as you do. Whatever your reason for exploring organic options for your dog, you’re wise to do a bit of research before making a switch. Of course, as with any decision related to diet and your dog’s health, check with your veterinarian before making any changes.

Sales of organic dog foods — foods grown without pesticides, preservatives, hormones, and antibiotics — are on the rise, up 48 percent from 2007 to 2008, according to the Organic Trade Association, which monitors organic market trends. Though organics still make up only a small fraction of domestic pet food sales, eco-conscious consumers are finding it easier to purchase the products they need. You can find brands such as Newman’s Own Organics and Natura Pet Products in many pet supply stores.

Often the reason behind a switch to organic begins with some sort of health issue. Skin conditions and allergies can be especially troublesome for some breeds. When sprays, dips, shampoos, medications, and even dietary changes don’t work, some owners turn to organic foods for success. Organic foods are free from the artificial dyes and chemical additives that can trigger a dog’s allergies.

Food for thought: Organic versus natural

Deciphering food labels can feel like a chore, but it’s a chore worth doing when you’re serious about good health. A particularly confusing labeling distinction — and one that applies to food for humans and canines alike — is the one between organic and natural. Don’t be misled — organic and natural are not the same. Organic foods must be certified as organic by the U.S. Department of Agriculture — that is, produced and processed without chemical pesticides, synthetic fertilizers, hormones, and antibiotics. Although natural foods are free of food coloring and chemical additives, they are not organic. So although natural foods have some benefits, they are not held to the same higher standard as organic foods.

In more serious cases, owners of dogs with cancer switch to packaged organic foods (kibble, canned food, treats), believing that organic food may give a sick dog ammunition for fighting the disease. Some people go as far as cooking meals for their dogs, although a veterinarian should first approve this type of diet.

So what are some advantages and disadvantages of organic dog foods? Take a look. As for the advantages, organic dog food

• Is produced without chemicals, steroids, or artificial colors and flavors.

• Contains better grades of grains and proteins to help with digestive issues such as gas or diarrhea.

• Has no bulk fillers, making food easier to digest. It may also help manage weight.

• May help with allergies and skin ailments.

• May help boost immunity, helping your dog ward off ailments.

Disadvantages include the following: Organic dog food

• Isn’t as widely distributed as conventional dog food.

• Is more expensive than nonorganic dog food. (The same situation is true of organic food for humans.)

• Has not been proven through scientific evidence to help your dog live a longer or healthier life.

Weigh these pros and cons, and think about what is best for your dog.

Proteins are the most critical component of food for your canine carnivore. They are also the most abundant component of your dog’s body. Your dog needs proteins to produce hair, nails, tendons, cartilage, and all the connective tissues that support the rest of the tissues and organs in her body. Adequate protein is important for your dog’s growth and proper development, her muscle development and strength, a functioning immune system, the production of functioning hormones, the proper volume of blood, injury repair and prevention, and much, much more.

Your dog’s body can also use proteins to produce energy, if necessary. Fats and carbohydrates are much more readily available sources of energy, but dogs can break down proteins and convert them to energy when necessary, such as when food supply is low.

Proteins are made up of amino acids linked in a chain. When your dog eats protein, enzymes that the pancreas secretes into the intestines break them down into shorter chains of amino acids called polypeptides, which are small enough for the intestines to absorb. A dog’s body makes 20 different amino acids — some are essential amino acids and others are nonessential amino acids. As the name implies, your dog requires essential amino acids in his food. Food that contains all the essential amino acids is called a complete protein source. The nonessential amino acids are … drum roll, please … not essential; if your dog doesn’t get them in his diet, he can convert other amino acids into those that he’s missing.

Your dog can get proteins from both animal and plant sources. But only animal-source proteins are complete protein sources, and not all of them are complete. Examples of complete protein sources that come from animals are eggs, whole milk, and lean meat. Grains are another important source of proteins in dog foods, but they are incomplete protein sources because they don’t contain some of the essential amino acids your dog needs. Plant protein sources frequently used in dog foods include soybeans, wheat, and corn.

Your dog’s major source of protein should be animal products, not grain. Don’t buy a dog food in which soybean meal, soy flour, or corn gluten meal is the primary, or even the secondary, source of protein (see the post “Reading a Dog Food Label” for more on this). Dogs don’t have the enzymes to use grains properly as main sources of protein.

The American Association of Feed Control Officials (AAFCO) is the organization that sets guidelines for the types and amounts of nutrients dogs need in their foods. The AAFCO has determined that foods for adult dogs should contain no less than 18 percent protein, and that foods for lactating females or puppies should have a minimum of 22 percent protein. Military or police dogs, mushing dogs, and other dogs who work hard every day or who are under stress may need more. Dogs recuperating from injuries or surgery may need more protein as well, to repair muscles, tendons, and ligaments.

Not all complete protein sources are created equal. A cow’s hoof and a filet mignon may both have all the essential and nonessential amino acids, but your dog can get the amino acids he needs more easily from the filet mignon than from the cow’s hoof. Some proteins are just more digestible than others. So how do we know which protein sources are digestible and which aren’t? Nutritionists measure the amount of protein in a food, feed it to dogs, and then measure the amount of protein in the dogs’ feces. The difference between how much was in the food to begin with and how much the dog excretes reveals how much of it the dog absorbed, and that is the digestible protein. A protein isn’t very useful to your dog if it ends up on your lawn rather than in his body. Hair and feathers are a cheap source of protein, too — but they’re indigestible. On the other hand, eggs are highly digestible but expensive. Not surprisingly, the more digestible the protein, the more expensive the dog food. As with many things in life, you get what you pay for.

Beware of foods that advertise over 90 percent digestibility. The highest-quality dog foods are 82-86 percent digestible, whereas economy foods (inexpensive brands you get in grocery stores) are around 75 percent. The percent digestibility of a dog food is not stated on the label, but most dog food manufacturers provide that information on request.

If your dog’s feces are voluminous, it may be a sign that his food isn’t highly digestible.

Before the late 19th century, there was no such thing as prepared dog food. Lucky dogs owned by the well-to-do ate the leftovers from their owners’ dinners, and street dogs aplenty canvassed the alleys, scrounging in the trash. In the 1870s, a time when transportation literally used horse power, a European entrepreneur devised a unique way to solve the problem of what to do with the carcasses of the many horses that died every day in the cities: He decided to package and sell the horse meat as dog food. The idea caught on, particularly among the wealthy, who appreciated the convenience of having a ready-made food for their dogs.

The first commercial dog foods in North America were made by Ralston-Purina in 1926. The foods were tested on dogs that the company kept in large kennels on the property near St. Louis, Missouri. Ralston-Purina dog food was given the ultimate test when it was fed to the sled dogs on Admiral Byrd’s expedition to Antarctica in 1933. Although this was a punishing test for a dog food, it also was an early precursor to the celebrity endorsements that are a major part of the advertising budgets for many large companies today.

In the decade after World War II, the idea of prepared dog food really caught on. The economy was booming and people didn’t mind spending a little money for the convenience of having a ready-made dog food for their canine companions. Besides, the companies producing these dog foods were performing studies on the nutritional needs of dogs, and their foods were billed as containing everything a healthy dog needed.

At that time, most dog foods were canned. This method of preserving food was familiar to Americans, who enjoyed the convenience of canned human foods that could be stored for months or even years on their shelves. In 1956, dog food companies began to utilize the extrusion process, in which nutrients in dried form are mixed with water and steam- and pressure-forced through an opening; the extruded material then is cut into small pieces. The food pieces are cooled, coated with vitamins and other components that are lost in the process of heating, flavored, and packaged.

Dry dog food allowed the consumer to more easily carry large amounts of dog food home from the grocery store. In addition, people found pouring food from a bag more convenient than opening a metal can. Plus, dry foods were advertised as helping keep dogs’ teeth cleaner. As a result, since the late 1960s, the majority of dogs have been fed dry dog food, although canned food is still widely used, especially for smaller dogs.

In the early 1970s,the National Research Council (NRC) published the first recommendations listing the minimal nutritional requirements of dogs. Dog food companies now had a standard by which they could measure the nutritional value of their foods and parameters by which they could claim their foods to be complete and balanced. (The term complete indicated that all the required nutrients were present in their foods, and balanced indicated that these nutrients were in the correct proportions.) The NRC nutrient requirements for dog foods were supplanted in 1992 by nutrient profiles established by the American Association of Feed Control Officials (AAFCO). Throughout the late 20th century, as the dog population continued to grow, so did the dog food industry. By 1999, the pet food industry was an $11 -billion-a-year industry — and very competitive. Today dog foods are advertised and marketed every bit as competitively as human foods, highlighting the importance of being aware of what you’re buying.

Fats are the major source of energy for dogs. Dogs who live outdoors in the cold need more fat to supply them with the energy to keep warm. And police dogs and working dogs need enough fat so they don’t have to get their energy from carbohydrate or protein supplies.

But fats do more than provide your dog with energy. They also help keep skin and foot pads supple and coats healthy. Supplying an allergic dog with the proper amount and type of fats can make a huge difference in how much she scratches. Fats also carry fat-soluble vitamins into the body from the intestines. These vitamins are essential for health, and the only way your dog can absorb them is if she eats enough fat to carry them into her body. Plus, just as with our own food, fat makes a dog’s food tastier, which can be important in helping dogs who are ill to eat enough.

Fatty acids are the major component of fat. Dogs really need only omega-6 fatty acid (linoleic acid), because they can’t make it on their own. Linoleic acid keeps your dog’s skin supple and pliable, and her pads and nose leather flexible. Dogs lacking linoleic acid have scruffy, dry coats and dry, cracked pads. Luckily, dogs don’t need a lot of linoleic acid. Good sources are beef, pork, chicken, and the oils from corn, safflower, and soybeans.

Omega-3 fatty acids can also help dogs with allergies by controlling the inflammatory responses in their skin. Omega-3s can improve dry skin and decrease stiffness from arthritis. But omega-6 and omega-3 fatty acids have some opposing functions, so you need to be sure that your dog is getting a balance between these two components. Shoot for a ratio of omega-6 to omega-3 fatty acids of about 5 to 1. Your dog is better off if her food has the correct ratio of omega-6 to omega-3 fatty acids than if you try to provide it in supplement form. Look for dog foods that have safflower oil or corn oil for omega-6 fatty acids, and fish oil or fish meal for omega-3 fatty acids.

The ratio of omega-6 to omega-3 fatty acids is listed on the bags of some of the better-quality foods, so if your dog is having skin problems, opt for a higher-quality food — and one with the correct ratio of omega-6 to omega-3.

Although your dog needs fat in her diet, too much fat can contribute to obesity, the number one nutritional problem in dogs. Excessive fat can also slow the digestive process and may cause nausea, diarrhea, and vomiting. High-fat diets also play a role in the development of pancreatitis, an inflammation of the pancreas that can result in very severe vomiting and sometimes even death. So you need to control the fat levels in your dog’s diet. Feeding a high-quality dog food (and not giving lots of extras), watching your dog’s weight, and making sure that she gets enough exercise is the best way of ensuring that she won’t become obese. On the other hand, that doesn’t mean a low-fat diet is good for dogs. Too little fat can lead to dry, flaky skin; dry, cracked pads; and a dull coat.

Be sure to read the dog food label before choosing a diet for your dog and observe your dog’s response to the food. If you don’t like the appearance of your dog’s coat and skin on one diet, try a different one.