Discussion

Most equine dermatoses, whether inflammatory or neoplastic, can become crusted and/or ulcerated at some point (Knottenbelt 2009; Scott and Miller 2011). I am going to confine my comments to dermatoses that are primarily crusted or ulcerative at presentation, and that have no significant associated visible or palpable mass (nodules, tumours, cysts, abscess). It is useful to prioritise crusting and ulcerative dermatoses on the basis of the region(s) of the body affected.
The approach to these dermatoses begins with a thorough history and physical examination (Knottenbelt 2009; Scott and Miller 2011). Laboratory tests are selected (or not) based on a prioritised (which is geographically variable) differential diagnosis (Knottenbelt 2009; Scott and Miller 2011). Investigations may include skin scrapings, trichography, cytology, culture, skin biopsy, therapeutic trials, and combinations of these (Knottenbelt 2009; Scott and Miller 2011).