Endocrinology is the science of hormones - the study of their physiology and pathology. Hormones are secreted by the endocrine glands. They are the body's messengers, transmitting long-distance information from their point of origin. Therefore, they play an important role in body functions. Consequently, any disease that affects the endocrine system can lead to general disorders ranging from simple skin problems to cardiacirregularities.
Simply put, disorders that affect the endocrine system fall into two categories. The first is hyperfunctioning, which entails overproduction of hormones. This is often the case with endocrine gland tumors. At the other end of the spectrum is secondary hypofunctioning, caused either by a drop in hormonal secretion, or when the body becomes resistant to hormonal action. With the thyroid gland for example, there is hypothyroidism and hyperthyroidism.
Each endocrine gland will be briefly described, after which the related diseases will be presented for each gland. Emphasis will be placed on clinical symptoms, especially those that should catch the attention of the owner. Finally, after an overview of treatments, the predisposed breeds will be described wherever possible. The goal of this chapter is to provide an overview, which is hardly exhaustive, of the primary disorders that affect canine endocrines.