Dorsal thermal necrosis in dogs: a retrospective analysis of 16 cases in the southwestern USA (2009-2016).

BACKGROUND

Prolonged sun exposure in high ambient temperatures has been recognized as a cause of thermal burns on the dorsal skin of dogs, termed dorsal thermal necrosis (DTN).

HYPOTHESES/OBJECTIVES: To characterize the clinical presentation, histopathology and outcomes of 16 dogs diagnosed with DTN and to identify associated risk factors.

ANIMALS

Sixteen dogs diagnosed with DTN.

METHODS

Medical records from 2009 to 2016 were reviewed retrospectively. Inclusion criteria included: (i) historical solar exposure; (ii) dorsal burn injuries and (iii) histopathological findings consistent with DTN.

RESULTS

The majority of cases (15 of 16) occurred during warmer months (May-September) in the southwestern USA. Affected dogs had predominantly dark, short hair coats, whereas four of 16 dogs had lighter coat colours. Five dogs had naturally longer hair, but two hair coats had been recently clipped. Signs consistent with heat exhaustion or heatstroke were reported prior to the development of cutaneous lesions in four of 16 dogs. The most common skin lesions were alopecia, erythema, ulcerations, eschars/necrosis and crusts. Histological findings were consistent with other types of partial and full-thickness thermal burns, and included coagulation necrosis in the majority of cases. Most dogs were treated supportively with analgesics and antimicrobial therapies. The majority of DTN wounds healed via second intention, although surgery was performed on two dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

Dorsal thermal necrosis should be considered as a differential diagnosis for dogs with dorsal cutaneous burns and a history of sun exposure in high external temperatures. Dogs with dark, short hair coats may be at an increased risk.