Obsolete names for the breed include Shepherd's Dog and bob-tailed sheep-dog. The nickname Bob-tail (or Bobtail) originates from how dogs of the breed traditionally had their tails docked. Old English Sheepdogs can grow very long coats with fur covering the face and eyes and do not shed unless brushed. The Old English Sheepdog Club of America sponsors investigations into diseases encountered in the breed in order to assist breeders in selecting healthy dogs for breeding, and breeders of Old English Sheepdogs who are members of the Old English Sheepdog Club of America must support its Code of Ethics in breeding and selling sheepdogs. Some diseases being investigated include hip dysplasia, cataracts, glaucoma, entropion, thyroid problems, deafness, diabetes, HD, PRA, allergies and skin problems. There is no data on how many dogs are affected, or what percent of the breed is affected by any of these ailments. Heatstroke is also a serious concern in full coated dogs.