Companion Animals

Dog Hypothyroidism Long-Term: Monitoring and Quality of Life

Canine hypothyroidism is common and highly manageable, but inadequate monitoring leads to suboptimal control and reduced welfare.

Key Facts

Canine hypothyroidism affects around 0.2% of dogs, with Golden Retrievers and Dobermans overrepresented
Levothyroxine replacement restores normal thyroid function when correctly dosed
TSH measurement as well as T4 enables better dose optimisation than T4 alone
Undertreatment causes weight gain, lethargy, and skin disease; overtreatment causes cardiac and behavioural effects

Welfare Considerations

Dogs with poorly controlled hypothyroidism live with chronic lethargy, weight-related joint stress, and skin problems. Regular monitoring enables dose adjustment that maintains normal quality of life. Owner recognition that normal-appearing symptoms like weight gain may indicate undertreated hypothyroidism improves welfare.

What You Can Do

Schedule thyroid level testing every 6 months in dogs on levothyroxine
Request both T4 and TSH measurement for complete thyroid function assessment
Watch for recurrence of hypothyroid signs - dosing requirements change over time