Canine hypothyroidism is one of the most common endocrine disorders in dogs, causing diverse clinical signs that significantly affect quality of life if undiagnosed or inadequately managed.
Undiagnosed or under-treated hypothyroidism causes chronic suffering that may be mistaken for ageing or obesity. Affected dogs experience persistent lethargy, mental dullness, and cold sensitivity — they are physically and psychologically compromised but may show little outward distress due to their gradual decline. Skin thickening, hair loss, and recurrent pyoderma cause discomfort. The neurological complications of severe hypothyroidism, including peripheral neuropathy, can cause pain and functional impairment. Fortunately, levothyroxine therapy is inexpensive, effective, and safe — most dogs show dramatic improvement within 4-8 weeks of correct dosing. Welfare depends on accurate diagnosis and consistent long-term management.