Pugs have a large amount of skin that is wrinkled on the head. This occurs because of the breed’s brachycephalic head confirmation (Nuttall et al 2009) and is the result of a discrepancy between the size of the Pug’s much foreshortened muzzle and the skin which covers it, which has not shown a similar and proportionate reduction.
Skin fold dermatitis occurs when the skin in these folds is irritated directly by hairs and skin rubbing together combined with the accumulation of skin secretions. Skin infections commonly occur in these situations and contribute to the welfare concerns.
Skin fold dermatitis is most common in puppies but adult dogs are also frequently affected. Constant low-grade skin irritation with more severe episodes of infection and pain may be expected throughout the lives of affected dogs.
Wrinkled skin and deep skin folds predispose affected animals to this condition. Any dog with skin folds because of a mismatch (as a result of selective breeding) between the size of the skin and the size of the underlying structures is at risk. Dogs with such skin are very likely to pass a predisposition to the disease on to their offspring.
Breeding from dogs with excessive folds of skin will perpetuate the problem, but breeding from those with normal skin and with no history of skin fold dermatitis should help prevent the disease being perpetuated. However, skin folds are likely to be present in Pugs because of their abnormal, brachycephalic, head shape and their abnormal, curled, tails. Whilst these abnormalities remain part of the breed standard of Pugs it may be hard to avoid skin folds and the diseases associated with them. The eradication of skin fold dermatitis may only be achievable by selecting for a normal head conformation and to achieve this, out-crossing may be required. Dogs that have shown any signs of skin fold dermatitis or that have had corrective surgery should not be used for breeding.