Huskies do not need coats. Greyhounds do. Most dogs sit between, and the answer changes with the weather and the dog's age.
Who needs one
Short or single coats, small bodies, thin dogs, puppies, and seniors. Anything below about 45 degrees for these dogs, and below freezing for medium-coated dogs on long walks.
What kind
Insulated for cold and dry. A shell for rain. A fleece for a chilly walk. Cover the chest and belly, and leave the legs free to move.
Fit
Measure back length from collar to base of tail. The coat should end before the tail so the dog can go to the bathroom without wetting it.
