Hypothyroidism in dogs is a condition where the thyroid gland does not produce enough hormones. This can lead to various health issues, including weight gain, lethargy, and skin problems. It is most commonly seen in middle-aged to older dogs and certain breeds, such as Golden Retrievers and Doberman Pinschers. Diagnosis typically involves blood tests to measure hormone levels. Treatment usually consists of daily medication to replace the missing hormones, which can help manage symptoms and improve the dog's quality of life. Regular veterinary check-ups are essential to monitor the dog's condition and adjust treatment as needed.