Hypothyroidism is among the most common endocrine disorders in dogs, causing weight gain, lethargy, skin problems, and behavioral changes. Early diagnosis and appropriate management dramatically improve affected dogs' quality of life.
Hypothyroidism is a significant welfare condition because untreated dogs experience chronic fatigue, weight gain with associated joint stress, skin discomfort, and potentially behavioral changes including anxiety and cognitive impairment. Many cases go undiagnosed for months or years because the signs — weight gain, lethargy — are attributed to aging or lifestyle. Diagnosis requires appropriate thyroid panel testing rather than T4 alone, and treatment with levothyroxine produces dramatic improvement in most dogs within weeks. The welfare cost of a missed or delayed diagnosis is months of preventable suffering for a highly treatable condition.