Suspected Calcinosis Cutis and Demodicosis, Secondary to an Exogenous Steroid Administration in a Dog with Hypoadrenocorticism

Abstract

Hypoadrenocorticism is an uncommon, life-threatening, disease with immune-mediated aetiology, caused by reduced production of glucocorticoids and often also mineralocorticoids. The treatment is supplementation of cortisol, and aldosterone analogues if needed. High exogenous glucocorticoid supplementation can result in iatrogenic hyperadrenocorticism, development of calcinosis cutis or immune-suppression leading to demodicosis.A 4-year-old female neutered Labrador retriever who was receiving treatment for hypoadrenocorticism, was presented for bilateral, symmetrical, well-demarcated areas of alopecia with multiple firm pale-yellow hard and gritty plaque-like lesions, erythematous papules and ulceration which had developed; six months later the dog was presented for generalised alopecia and erythema. Diagnostics investigation for the plaque lesions included cytological examination which revealed amorphous glassy and transparent material and evidence of crystals compatible with calcinosis cutis.Skin scrapes of the areas of alopecia and erythema revealed Demodex spp. A reduction of glucocorticoids resulted in resolution of calcinosis cutis and treatment with a fluralaner chewable tablet (Bravecto®, MSD) treated her demodicosis.