Hypothyroidism is a common endocrine disorder in middle-aged and senior dogs that causes significant welfare impact through multiple body systems when undiagnosed.
Hypothyroidism causes chronic, progressive welfare compromise that develops insidiously. Affected dogs become lethargic, seek warmth, gain weight, and lose their hair - changes that owners often attribute to normal aging. The welfare impact is significant: these dogs are chronically cold, uncomfortable in their skin, and physically limited by their condition. The tragedy of hypothyroidism as a welfare issue is how completely treatable it is - levothyroxine supplementation typically produces dramatic improvement within weeks, restoring quality of life to near-normal. Delayed diagnosis means prolonged unnecessary suffering.