ISVD‐4 Deep cutaneous ulcerations secondary to atherosclerosis in a hypothyroid dog

Abstract

The purpose of this report is to describe the clinical and histopathological characteristics of deep cutaneous ulcerations secondary to atherosclerosis. A 5‐year‐old Dalmatian dog was presented with slowly progressive, slightly puritic, nonpainful skin ulcers involving the lateral tarsus, the inner thigh, and one footpad. The hair coat was greasy, dull and covered by oily scales. The tail was alopecic. The dog was abnormally quiet, bradycardic and had a swollen puffy face. Complete blood count revealed a moderate anaemia, and the chemistry panel revealed a severe hypercholesterolemia (12.03 g/L) and hypertriglyceridemia (7.91 g/L). Endocrine tests unveiled low serum T4 (<4.67 ng/mL) and high endogenous TSH (2.08 ng/mL). Histological examination of skin biopsy specimens demonstrated deep chronic ulcers. Beneath these ulcers, deep dermal and subcutaneous medium to large arteries exhibited variable degrees of sclerosis, multiple foci of lipid deposition, and large foamy lipid‐laden histiocytes infiltrating within the tunica intima and media. Rare neutrophils and lymphocytes occasionally infiltrated the arterial walls. Oral thyroxin supplementation induced rapid changes in the dog's attitude, facial swelling and heart rate. The hair coat improved dramatically and ulcers rapidly healed following treatment implementation. There are only rare descriptions of clinical consequences of atherosclerosis in the veterinary literature. To our knowledge, this is the first report of atherosclerosis‐related cutaneous ulceration in dogs. Atherosclerosis is rare in this species, where it most often occurs secondary to diabetes mellitus and hypothyroidism. Ischaemia induced by atheromatous plaques and secondary thrombosis is likely the cause of the skin ulceration in this patient. Funding: Self‐funded.