Epidermal Renewal After Treatment of Primary Canine Hypothyroidism Using Levothyroxine

In a case study of a 7-year-old Dalmatian bitch diagnosed with primary hypothyroidism, treatment with levothyroxine was found to be effective in restoring normal epidermal patterns and reversing symptoms such as alopecia, dry brittle hair, and skin lesions. The dog had initially presented with symptoms including weight gain, rough hair, symmetrical erythematous skin lesions, lethargy, and fatigue, along with abnormal blood and biochemical test results, and a cervical ultrasound indicating thyroiditis. Hormonal tests showed high TSH and low T4 levels. After treatment with levothyroxine, the dog's epidermal renewal was restored, and other parameters returned to normal. The study suggests that T3, which is affected by hypothyroidism, plays a role in keratinocyte differentiation and epidermal renewal, potentially mediated by epidermal growth factor or gene expression. The case supports the effectiveness of levothyroxine in treating dermatopathies associated with hypothyroidism in dogs.