Some dogs’ coats have two layers – the undercoat, which repels water and keeps the skin warm and dry, and the outer layer, which is more course.
Dogs Most Likely to Need a Winter Coat
These breeds do not have an undercoat and are less protected from the cold:
Portuguese Water Dog
Dogs Most Likely Not to Need a Winter Coat
These breeds do have two-layer coats:
Bernese Mountain Dog
Old English Sheepdog
Spitz-type dogs (Akita, Alaskan Malamute, Chow Chow, Husky, Pomeranian, Shiba Inu and Samoyed) and Wests.
**Always look for signs that your dog is too cold, regardless of their breed, and do not leave your dog outside in the cold for extended periods of time**