Talking food bowls, pet doorbells, basketball hoops for birds and GPS systems for Fido were just a sampling of the more than 850 new products unveiled earlier this month at the pet industry's largest annual trade show in San Diego.

Pets are big business, and the inventors of this dizzying array of merchandise hope to grab a piece of the $40 billion that Americans spend annually on their pets.

There was no limit to the imagination.

Best of Show among new cat products at the Global Pet Expo was the Undercover Mouse, an electronic device that skitters under a durable nylon cover designed to give your cat hours of fun. Random teasing motions draw cats into play. The speed can be adjusted and operates on three AA batteries ($32.95, available at Petco or online at www.panicmouseinc.com).

A product to keep your pudgy pooch moving is the DogTread, which won third place in innovative new dog products. More than 40 percent of pets are obese, and providing dogs with enough exercise is difficult for many owners with busy schedules or strict leash laws in their community, says Krista Wickens, owner of PetZen Products in Ogden, Utah, which created the motorized treadmill. The DogTread operates from .3 mph to 5 mph and serves pets up to 30 pounds ($499.99 from petzenproducts.com). Models for medium and large dogs will be introduced this spring.

Many of the new products were improvements on old ideas, such as the Best-of-Show winner in the dog category: the Comfy Cone, a flexible Elizabethan collar for dogs to wear around their necks after surgery to keep them from bothering the treated area. It's made of nylon fabric laminated onto a half inch layer of foam to make them soft and yielding. (Available from Arcata Pet Supplies in various sizes for $12.79-$27.75, www.arcatapet.com, 1-800-822-9085.)

Among other new products is Zoombak's Advanced GPS Dog Locator ($199), a handy device if your dog has a habit of going AWOL. A small, lightweight locator attaches to your dog's collar. His location can be pinpointed via Zoombak.com, mobile phone or live customer care.

Does your dog miss you when you're away? Resolve that with ChatterBowl, a food or water bowl that records your voice and plays it back when your pet approaches. You can record messages up to 10 seconds long and change them as often as you wish. (Created by Contech of British Columbia, $24.99 from www.contech-inc.com or other online stores.)

Paris Hilton no doubt will invest in Pet Creations, a Brooklyn, N.Y., company that has introduced My Petshirt, an all-in-one sweatshirt and pet carrier for teacup breeds (those less than 9 pounds).

Speaking of tiny pets, Nature's Instinct introduced the Birdie Basketball Gym to train your feathered friend in hoops. Teach your bird to make a basket, and a treat is automatically dispensed. Comes with agility rings and dumbbell. Information at www.natures instinct.com.

The expo, which was not open to the public, is presented by the American Pet Products Manufacturers Association and Pet Industry Distributors Association.