When humans first domesticated dogs, we fed them scraps from our meals. Those early dogs did just fine on that diet. As our affection for dogs has grown over the centuries, so has our understanding of what our canine companions need to eat to live long, healthy lives. Research conducted by veterinarians and pet food manufacturers over the last decade have revealed more specific details about what a dog's diet should contain.

Your dog's food must be appropriate for her size, age, state of health and activity level. As you stroll the isles of pet supply stores or grocery stores, you'll find a variety of food brands in a wide range of prices. A good basic rule of thumb is to buy the highest quality food you can afford. If you buy the cheapest food because you have a big dog that eats a lot, you must understand that what you save in food will affect your pet's health.

It is important that your dog always eats some dry food. The crunchy pieces help keep her teeth clean and her gums healthy, and provide necessary fiber. If you choose to give your dog moist food in addition to dry, use it sparingly; a small spoonful mixed with warm water makes a good gravy over dry kibble. Some devoted dog lovers feed their pets home-cooked food. Dog-specific recipes can be found on the Internet and in books, but understand that this is not just giving your dog leftovers from your own meals. Homemade dog food is designed to meet the nutritional and digestive needs of dogs. Spices, fats, and fillers in human food often makes dogs ill.

Adult dogs should be fed two meals each day. Puppies need to eat more often. They should be fed three to four meals daily until they are 12 weeks old, then three meals daily until they are six months old. Many dog trainers advise against leaving food available all day, to prevent dogs developing picky eating habits. They suggest you allow 20 minutes for each meal. After this time, whatever has not been eaten should be picked up. Dry food can be held until the next meal, but moist food should be thrown away. It is very important to make sure your dog has plenty of clean water available at a all times.

The amount you feed your dog depends on her age, weight and activity level. Check the back of food or with your veterinarian to get an idea of how much your dog should be eating. Monitor your dog's weight by running your hands along the sides of her body. If she is at the right weight, you will be able to feel her ribs without pressing. If you can't feel her ribs, she is gaining weight and you should either slightly decrease the amount of food or increase the amount of exercise she gets. If you can easily see your dog's ribs, she is underweight (except in certain breeds.)