The adrenal glands, pituitary glands and the hypothalamus are responsible for much of the regulation of body processes including digestion, energy usage, and the immune system. The adrenal glands are located near the kidneys and produce many of the most important hormones such as sex hormones, epinephrine and noradrenaline for the “fight or flight” response, and glucocorticoids. Of the glucocorticoids, cortisol is the most critical. An over production of cortisol is known as Cushing’s syndrome or hyperadrenocorticism while reduced production is known as Addison’s disease or hypoadrenocorticism.
Cushing's Syndrome in Dogs
Cushing’s syndrome is the most common endocrine disease in dogs. Clinical signs of disease include increased thirst and hunger, increase urination, skin lesions, and behavior changes.
Addison’s Disease in Dogs
Addison’s disease in dogs tends to more acute and can rapidly alter the blood electrolyte levels resulting in a decreased heart rate.
Cortisol levels are easily monitored using a cortisol assay. Traditionally, blood was used as the sample but salivary and urinary cortisol correlated very well with blood concentrations. When urine is used as the sample, creatinine should also be tested.
- RF Vining, et al., Salivary Cortisol: A Better Measure of Adrenal Cortical Function than Serum Cortisol, Annals of Clinical Biochemistry, vol. 20, 6: pp. 329-335. First Published Nov 1, 1983.
- SC Klein and ME Peterson, Canine hypoadrenocorticism: Part 1; Canadian Veterinary Journal 51(1): 63-69, 2010
- SC Klein and ME Peterson, Canine hypoadrenocorticism: Part 1; Canadian Veterinary Journal 51(2): 179-184, 2010