This is the medical term for an overactive thyroid gland. One of the many things the thyroid gland is responsible for is to regulate metabolism. When too much thyroid hormone is secreted, the metabolism quickens; secreting too little results in hypothyroidism and a slowed metabolism.
Hyperthyroidism is an endocrine disease, like diabetes; those with endocrine-related disorders are more prone to various types of neuropathy. As with diabetes mellitus, hyperthyroidism can mean polydipsia and polyuria symptoms.  It is not a common problem in dogs,  but it's important to remember overmedicating for hypothyroidism can show up as hyperthyroid test results.
- ↑ Diabetes Mellitus-Symptoms Common to Other Diseases. Petplace.com.
- ↑ Church, David B. (2009). Hyperthyroidism. WSAVA.
- Neurological Consequences of Thyroid Disorders Cauzinille, Laurent, 2005 WSAVA
- Mechanism of Action & Effects of Thyroid Hormones CSU--details hypothyroidism & hyperthyroidism
- Gastrointestinal Signs of Endocrine Disorders-Dogs & Cats Provet UK
- Endocrine Emergencies Wallace, Melissa S., 2001, Atlantic Coast Veterinary Conference