Hyperthyroid Symptoms in Dogs

Hyperthyroid symptoms in dogs occur when hyperthyroidism, a disease of the endocrine system, develops. In hyperthyroidism, the thyroid gland, a small gland in the throat that produces metabolic thyroid hormones, becomes overactive. As a result, it produces too much hormone, which can lead to severe metabolic problems. Read on to learn more about the symptoms and treatment of this endocrine disorder of dogs.

Causes of Hyperthyroidism in Dogs

Hyperthyroidism is a relatively rare canine disorder. Hypothyroidism, a disorder which causes the thyroid gland to produce too little of its hormone, is far more common. Hyperthyroidism in dogs is usually caused by carcinoma of the thyroid gland. It occurs most often in geriatric animals.

Dogs with hypothyroidism can develop hyperthyroid symptoms if they are given too much medication. The medication used to treat hypothyroidism contains a synthetic version of the thyroid hormone. If the dose of thyroid hormone is too high, it can have the same effect of your dog's body as an overactive thyroid gland. Your vet can adjust your dog's dosage to relieve symptoms.

Symptoms of Hyperthyroidism in Dogs

Dogs with overactive thyroids will continue to lose weight even though they are eating as much or more than they ever did. They may appear excessively hungry, and eat so fast that they throw up. They may experience diarrhea, excessive thirst and frequent urination. Weakness and muscle wasting can occur along with weight loss. 

Dogs with hyperthyroidism may experience elevated heart rate, and may become irritable, restless and hyperactive. They may breathe more rapidly. Their fur may become shaggy and dull in appearance. 

If your dog is experiencing symptoms of hyperthyroidism, it's important to seek veterinary care right away. When left untreated hyperthyroidism can be deadly.

Diagnosing and Treating Hyperthyroidism in Dogs

Hyperthyroidism in dogs can often be diagnosed with a simple blood test, measuring the levels of thyroid hormone in your dog's blood. Treatment can involve surgery, medication and radiation therapy. In some cases, medication can be administered to lower production of hormones by the thyroid gland.

If your dog has cancer of the thyroid gland, or an enlarged thyroid gland, surgery can remove part or all of the gland. Afterward, your dog may need to receive daily doses of synthetic thyroid hormone to help regulate his metabolism. Radioactive iodine can be injected into your dog's thyroid to kill cancerous cells, but he may still need medication afterward. Treatment may vary depending on your dog's age and general state of health; some treatments may not be appropriate for all dogs.

Homeopathic and herbal treatments can be used alongside more traditional medical treatments to ease your dog's restlessness and agitation. Herbs such as lemon grass, bungleweed and valerian help relieve stress and tension while inhibiting thyroid gland activity.

No matter what treatment your dog receives, he will most likely need medication every day for the rest of his life. With treatment, however, many dogs enjoy years of quality life.