The endocrine system is a collection of glands that control hormones throughout the canine body. The hormones then help to regulate and coordinate many of the body’s functions. The pituitary, adrenal, thyroid, parathyroid, and hypothalamus glands are part of this system of regulation, as are the testes and ova of the reproductive organs. The endocrine system may over- or under produce hormones, creating an imbalance that causes a variety of signs and symptoms in dogs which can range from the subtle to the severe.
Imbalance of the adrenal organs can cause a condition called alopecia, in which the dog begins to lose hair either in patches or with a general thinness throughout the coat. This problem is associated with an imbalance in reproductive hormones of the endocrine system.
Muscle weakness can be a feature of Addison’s disease, caused by a deficiency of cortisone and aldosterone in the adrenal glands. Low heart rate, vomiting, low blood sugar and collapse are other symptoms of Addison’s disease in dogs. Muscle weakness is also a symptom of imbalance of the parathyroid gland.
Weight loss can be a sign of overproduction of the hormone thyroxine by the thyroid gland. This condition can also cause excessive activity, diarrhea and high blood pressure. This imbalance is often caused by tumors on the thyroid gland.
An imbalance in production by the adrenal glands called Cushing’s disease is a common endocrine imbalance in dogs. It causes a distended abdomen, giving the dog a pot-bellied appearance. It also causes hair loss, increased appetite, increased water consumption and panting. Imbalances of the thyroid gland can also cause weight gain in dogs.
Underproduction of the parathyroid hormone can cause seizures along with twitching, tremors and trouble walking. The seizures are often associating with underutilization of calcium in the dog’s system. Other signs of parathyroid imbalance include weakness and muscle tremors.
Diabetes, an inability of the pancreas to produce insulin, is a sign of endocrine imbalance in the canine body. It can produce symptoms such as increased thirst, increased urination, weight loss, muscle weakness and development of cataracts in the eyes.
An imbalance of reproductive hormones can also cause urinary incontinence in dogs of both sexes. Incontinence can also lead to bladder infections, as well as skin infections around the genito-urinary area. Veterinarians treat this problem with hormone therapy and with medications to help strengthen the muscles of the bladder.