It involves pulling out the long hairs of the outer coat, and it does not hurt the dog if you wait until the coat is ready to be stripped. If the hairs don't come out easily, the dog is not yet ready to be stripped. A new outer coat will grow in to a show-quality length in about three months, and after approximately another three months it will be time to strip again. Stripping the coat, as opposed to clipping it, encourages a harsher coat, which is less likely to attract burrs and stickers in the dog which has access to nature. In general, Glens are a strong breed, robust and healthy.
Some Glens do have skin allergies.
The breed literature claims that there are no known diseases of the Glen, however, until recently no one had tested for any such diseases. The Glen has a limited gene pool and a history of inbreeding, which increases the risk of inheriting genetic diseases. Hip dysplasia can be identified in a breeding animal by x-rays by the age of two. Yearly certification by a veterinary ophthalmologist ensures the breeding stock does not exhibit any eye disease. I encourage all breeders to have their breeding stock screened for heritable genetic diseases which have been identified in the breed.