Walmart launches premium dog food

Walmart announced today that it's expanding its dog food line to include a new premium dry dog food, Pure Balance. The new food includes no soy, wheat or corn additives, no artificial colors, no preservatives and no chicken by-products.

Walmart is already a strong retailer in the pet food arena, selling enough dog food to fill an olympic-sized swimming pool more than five times each day, according to the company. And the move to premium food puts the big-box giant in even more direct competition with pet-focused retail outlets such as PetSmart and Petco. According to the American Pet Products Association, consumers will spend nearly $21 billion on pet food in 2012.

"Walmart is a force to be reckoned with," says John Volk, a veterinary analyst and consultant with Brakke Consulting. "And clearly they're capitalizing on a consumer trend away from grain and byproducts. But the impact on veterinarians shouldn't be that great. Wellness foods represent a pretty minor source of revenue in veterinary practices today."