Booming pet industry fetches strong return.(GLOBAL PET EXPO)

ORLANDO -- The-mass market and even pet specialty chains are only scratching the surface of the $40 billion pet products industry judging from the disparity between the array of items available at the industry's largest trade show and the more limited assortment found at retail.

Pet product industry sales this year are expected to increase 5.9% to $40.8 billion from $38.5 billion in 2006, according to the American Pet Product Manufacturers Association. That is nearly double the level from just 10 years ago when Americans spent roughly $21 billion on pets and it explains why attendance at the Global Pet Expo trade show held last month in Orlando continues to grow. This year's show drew 750 exhibitors compared to 700 last year and the show floor was expanded to 230,000 square feet from 215,000 square feet.

Caring for a pet's health is the most powerful trend in the industry, according to APPMA president Bob Vetere. That trend is driving sales throughout all industry segments, but particularly in the food category where claims of all-natural, preservative-free, fresh, organic and premium are commonplace.

"We had a real push over the last few years to …