Dietary Management of Hyperthyroidism in a Dog

Area of Science:

• Veterinary Medicine
• Endocrinology

Background:

• Hyperthyroidism in dogs is uncommon but can be caused by active thyroid masses.
• Clinical signs include weight loss, increased appetite, and hypertension.

Observation:

• An 8-year-old female spayed golden retriever presented with ventral cervical masses, weight loss, and hypertension.
• Initial serum thyroxine (T4) was 8.0 ug/dL (normal 0.8-3.5 ug/dL) and systolic blood pressure was 200-210 mmHg.

Findings:

• Conservative management with methimazole initially decreased T4 to 5.0 ug/dL.
• An iodine-restricted feline diet further reduced T4, improved clinical signs (anxiety, sleep), and lowered blood pressure.
• Diet withdrawal temporarily increased T4, which normalized upon reintroduction.

Implications:

• An iodine-restricted diet can be an effective adjunctive therapy for canine hyperthyroidism.
• Dietary modification offers a conservative management option, especially when financial constraints exist.
• This case highlights the potential of therapeutic diets in managing canine endocrine disorders.