4 Sarcoptic mange
Sarcoptic mange (also referred to as scabies) is a highly contagious, intensely pruritic and potentially zoonotic skin condition, due to an infestation of the skin by a sarcoptid mite Sarcoptes scabiei var. canis. The presenting signs of pruritus – papules, crusting, scaling, erythema and self-induced alopecia – are often confused with other dermatological conditions, such as staphylococcal pyoderma, allergic skin diseases or other ectoparasitic diseases.
All dogs present with a history of intense pruritus, which in most cases fail to respond to increasing doses of glucocorticoids. The onset of pruritus tends to be sudden and severe, and the animal is usually presented shortly after onset, unless the individual has been intermittently treated with ectoparasiticidal products. A history of indirect contact with foxes is usually noted, especially in urban and suburban areas of the UK. Sarcoptic mange is contagious and of zoonotic importance, and evidence of contagion and zoonosis may come to light during the history taking.
The clinical signs can range from subtle lesions with marked pruritus to severe lesions. The primary lesions include erythematous and/or crusted papules, and secondary lesions include crusts, lichenification, scaling and hyperpigmentation. Initial lesion distribution tends to be on the ear margins, elbows, sternum and the hocks. If untreated the lesions can become widespread and often affect the demeanour of the dog, as in this case.