Haemato-biochemical Alterations and Therapeutic Management of Hypothyroidism in Dogs

Abstract

Canine hypothyroidism is an endocrine disorder associated with clinical, haemato-biochemical and hormonal alterations. This study evaluated clinical manifestations, laboratory changes and therapeutic response in dogs diagnosed with hypothyroidism. Dogs presented with clinical signs suggestive of hypothyroidism, including symmetrical alopecia, sparse coat, dry and brittle hair, rat-tail appearance, seborrhoea, pyoderma and obesity, were examined at the Veterinary Clinical Complex. Diagnosis was based on history, clinical examination, haemato-biochemical evaluation and thyroid profile assessment. Six hypothyroid dogs were compared with six clinically healthy, dewormed and vaccinated control dogs. The most frequent clinical signs in affected dogs were obesity and bilateral symmetrical alopecia, followed by rat-tail appearance, secondary skin infection, reduced exercise tolerance, pruritus and dry, dull coat. Hypothyroid dogs showed reduced haemoglobin concentration, packed cell volume, total erythrocyte count, total T4 and total T3 concentrations, with increased thyroid-stimulating hormone concentration. Total leucocyte count, neutrophil percentage, alkaline phosphatase, triglycerides and cholesterol were also increased. Following confirmation of diagnosis, affected dogs received oral levothyroxine sodium at 0.02 mg/kg body weight once daily, along with symptomatic and supportive treatment. Clinical improvement was observed within 4 to 8 weeks, including improved activity, hair regrowth and body condition. These findings indicate that combined clinical, haemato-biochemical and thyroid profile assessment is useful for diagnosis and monitoring of hypothyroidism in dogs.