The endocrine system is made up of a group of tissues (mostly glands) that release hormones into the bloodstream. These hormones regulate metabolism, growth, development, and reproduction and are dispersed to different areas of the body, depending on the hormone’s function. When a hormonal balance is disturbed (by a tumor or autoimmune disease, for instance), an endocrine disorder can develop. “Hyper” refers to an excess of hormone, and “hypo” refers to a deficiency in a hormone. Treatment varies depending on the disease.
There are several common endocrine disorders found in dogs and cats:
Diabetes mellitus is caused by a deficiency in or resistance to the hormone insulin.
Hypothyroidism, which is often diagnosed in dogs, indicates that the animal has low levels of thyroid hormone.
Hyperthyroidism, which frequently affects cats, indicates that the animal has high levels of thyroid hormones.
Addison’s disease (hypoadrenocorticism) and Cushing’s disease (hyperadrenocorticism) can also affect both species, although Cushing’s disease is rare in cats.