Winter never fazed Foxy until late in life. Then, chilled by the snow and slush she used to live for, the German shepherd mix got her first winter coat and boots.

They took a little getting used to. "But soon my old lady was trotting around again. She was happy she could stay outside in the cold longer," says Diane Dewberry, Foxy's owner.

Seeing how the dog's new duds improved her quality of life, Dewberry decided to start carrying dog wear in her South Boston pet shop. Today, customers in all shapes and sizes come in for their canine couture: Greyhounds and dobermans on the larger end and Yorkshire terriers, miniature poodles, and shih tzus on the smaller.

Older dogs, sick dogs and those with very thin or very short coats are most in need of cozy cover-ups. For instance, Yorkshire terriers have thin coats and no downy layer underneath to insulate them from the cold. Small dogs also are more likely to rub up against the wet, cold snow.

"Some dogs just love dressing up," says Dewberry. "They like the reaction they get."

Dressing Dogs Can Be a Challenge

But many dogs don't. Dressing them can be a challenge, particularly in the shoe department. Still, says Dewberry, "Jackets and boots are a great thing for geriatrics. The salt kills their feet, and the ice gets stuck in their pads. When they're arthritic and try to lick their paws they fall over."

The Arctic air that socked the United States with an unusually cold winter last year spurred sales of canine winter-wear, and first-time customers face a wealth of styles straight out of Dogue magazine. What was once strictly a utility category is now high fashion, with animal prints, fleece and fur-trim vying for your doggie dollars.

In New York, one Park Avenue retailer sells $130 embroidered wool jackets to canine trendsetters. But your average pups, and their paying companions, prefer something a little more basic, around $20 to $40.

"Most of our customers are just looking to keep their dogs warm in the winter," says Kerrie Green of Animal Instincts in Reiserstown, Md. "A lot of people buy jackets the same color as the bows in the dog's hair."

Shopping Tips for Shivering Dogs

Look for simply styled jackets or sweaters in easy-care colors. After an hour at the dog park, that pretty pink vest will blend in with the mud.

Make sure the jacket or boots fit comfortably. Too small or too large, they will hamper your pup's movement.

If rain and snow are a concern, choose something warm and waterproof like a lined nylon cover-up.

Think about durability. Although pull-on sweaters cost less than adjustable coats, they have a shorter life span (usually just one season) and are harder to get on, especially for long-legged or arthritic dogs.

Choose something dignified, particularly for rough and tumble types. No self-respecting hound cares about dressing to the (ca)nines.