More than 50 million people in the United States have pets, and pet supply stores are competing to get their fair share of this lucrative market. If you are a pet owner, this is great news. Pet supply stores are continually improving their products and services, and you can choose from among many of them the right one for you.

Free delivery. You love your pet, but sometimes, you just don't have time to drop by a pet store to buy food and supplies. No problem - you can have everything delivered right to your doorstep. Most pet supply stores now offer free delivery of the freshest pet food and newest supplies. Steer clear of the inconvenience of pet supply shopping, or running out of pet food. Just order either online or from a catalog.

All-natural pet food products. People are becoming more health-conscious, even with their pets. That is why some pet supply stores now claim to only carry naturally-preserved pet food that do not contain artificial coloring, ingredients or byproducts. Some pet supply stores limit their selection only to pet foods that have passed complete feeding tests ongoing quality assurance checks.

Carefully-chosen pet supplies. There are now many pet supply stores that only sell 100 percent safe and non-toxic pet supplies, especially for dogs. These stores have only clinically-proven safe pet shampoos, creams and medicine in stock. You can also buy harmless pet toys and accessories from such stores.

Veterinarians on call. Most pet supply stores now have in-house veterinarians who can help you choose the right products for your pets. These vets are also on-call to help you if your pet suddenly reacts differently to a product. Best of all, these vets are just great sources of free advice. Just pop in the pet supply store and chat with them - you just might get free opinion on common pet problems.