Introduction
- Cause : unclear.
- Signs : plaque-like or discrete nodular skin disease.
- Diagnosis : history, clinical signs, histopathology, cytopathology.
- Treatment : systemic and topical antimicrobials, clipping.
- Prognosis : good.
Diagnosis
Clinical signs
- Sharply dermarcated erythematous, slightly elevated plaques.
- Self-trauma removes hair from affected area and causes an eroded or ulcerated lesion.
- Exudate mats the hair.
- Satellite lesions: begin as moderately well-demarcated erythematous macules or plaques beyond the traumatized margin of the central lesion, later obliterative self-trauma occurs.
- Palpation reveals lesion to be dermal/epidermal.
- Multifocal.
- Cheek and neck commonly affected.
Diagnosis
Differential diagnosis
- Pyotraumatic dermatitis
.
- Demodicosis .
- Hypersensitivity.
- Ectoparasitic infection .
- Dermatophytosis .
- Focal Malasseziadermatitis .
- Neoplasia .
- Fixed drug eruptions.
- Calcinosis cutis.
- Localized vasculitis.
Sequelae
Prognosis
- Good: if predisposing factors removed.
Expected response to treatment
- Regression of signs, usually within 4-12 weeks.
Reasons for treatment failure
- Predisposing factors not identified and resolved.
- Concurrent corticosteroid therapy.
- Inappropriate use of topical antimicrobials, eg insufficient contact time, or systemic antibacterials, eg underdosing: dose +/- duration.
Sources
Publications
Refereed papers
- Mason I S (1993) The selection and use of antibacterial agents in canine pyoderma. In Practice 15 , 129-134.
- Mason I S (1991) Canine pyoderma. JSAP 32 , 381.
- Reinke S I, Stannard A A, Ihrke P J et al(1987) Histologic features of pyotraumatic dermatitis. JAVMA 190 , 57-60.
Other sources of information
- Ihrke P J (1996) Bacterial skin disease in the dog. A guide to canine pyoderma. Veterinary learning systems, USA, pp 47-49 (Detailed and well presented).
