Goiters in Dogs

Goiter in dogs occurs when the thyroid gland swells and becomes enlarged. It is a benign condition that signals to your veterinarian that there is an underlying medical condition that will require treatment.

The thyroid gland is located in your dog’s neck, where it produces the hormone thyroxine (T4), along with several other important thyroid hormones. These hormones play a large role in your dog’s metabolism and can cause major problems when they are not produced at normal levels. The thyroid is like the thermostat of the body. An enlarged thyroid gland is, by definition, a goiter.

Most goiters in dogs are caused by genetic defects, or they develop as a side effect of administration of trimethoprim-sulfa, an antibiotic used to treat a variety of infections in dogs ,according to veterinarians.

Causes of Goiters in Dogs

Common causes of goiters in dogs include:

• enlarged thyroid gland
• idiopathic
• in-utero iodine deficiency or excess
• iodine deficiency
• iodine toxicity
• ingestion of goitrogenic plants
• hereditary familial goiter
• congenital hypothyroidism and dysmaturity syndrome in foals

Signs and Symptoms of Goiters in Dogs

It is imperative that both goiters and other thyroid conditions be treated, so dog owners must be able to recognize the symptoms of goiter in their dog.

Signs and symptoms of goiters in dogs can include:

• Dysphagia (difficulty swallowing)
• Dyspnea (shortness of breath at rest)
• Dyspnea on exertion (shortness of breath during activities)
• Wheezing sounds on inhalation or exhalation
• Lack of interest in food
• Sudden weight loss
• In most cases, goiters in dogs will resolve on their own once the condition of the thyroid is treated.

Treatment of Goiters in Dogs

In cases where the goiter is relatively small, they will eventually resolve on their own once the thyroid condition has been treated. Your veterinarian will closely monitor your dog’s progress throughout treatments to ensure that the goiter is receding.

There are some dogs that have a goiter that is too large to recede without intervention. In these cases, surgical removal of the goiter is necessary. This is done under general anesthetic. Generally, when the goiter is removed, the entire thyroid gland is also removed; this procedure is called a thyroidectomy. Dogs have two thyroid glands and when one of those glands is completely removed, hormone replacement therapy must be conducted to compensate for the loss.