"Ask your veterinarian to refer you to a specialist with an advanced degree in animal nutrition, certified by the American College of Veterinary Nutrition," she says.

Start Simple

If you're too busy to cook but want to add some natural food to your pet's diet, start with a natural, high-quality pet food -- one with no artificial preservatives, colorings or flavorings. Mix it with vegetables, grains and meats, and add a vitamin and mineral supplement, says Gardner. Chemicals to avoid include BHA, BHT and ethoxyquin. Dr. Ihor Basko, a Hawaii-based holistic veterinarian, recommends introducing a new diet gradually, since sudden changes can lead to vomiting and diarrhea. Other things to consider include your pet's age, health, metabolic rate, activity level and breed.

Finally, beware of scams that prey on your fears. Remember that marketing can be skewed to make you believe just about anything. As with nutrition for humans, pet nutrition hype is as close as a Google search away.

Separating the hype from reality is the first step to making informed decisions about what to feed your pet to keep it healthy and happy for its entire life.