Challenges in Managing Local Cutaneous Adverse Drug Reactions (CADR) – A Case Report

This report describes a rare case of a presumed local cutaneous drug reaction in a 10-year old, male miniature short-haired dachshund after subcutaneous injection of meloxicam and maropitant. The dog was presented with cubital joint lameness and meloxicam was injected subcutaneously. Bloody diarrhoea and bloody emesis developed over the next three days. After a repeated subcutaneous application of meloxicam and maropitant into the left thoracic wall, the skin and subcutis at the injection site indurated and became painful over an area of approx. 8x8 cm. The skin became locally necrotic and was demarcated within a few days. Histopathology of deep skin biopsies revealed severe, necrosuppurative dermatitis, panniculitis and vasculitis with marked edema and deep sequestrating pannicular necrosis. Perivascular eosinophils and vascular thrombosis were present in deeper areas of the panniculus and cutaneous muscle. Microbiological culturing failed to identify bacterial growth. Based on the treatment history, clinical changes, histopathology and the lack of laboratory data suggestive of relevant differential diagnoses, a local cutaneous adverse drug reaction (CADR) was favoured. Surgical removal of affected areas and an open wound management were successful and the dog fully recovered. This rare case of localized canine CADR illustrates the importance of a precise medical history, a strategie to exclude relevant differential diagnoses and the difficulties in ultimately confirming localized CADR in veterinary medicine.