The term ‘organic’ is contextual and has various meanings. For the purpose of this article organic means as much as it relates to bodily organs.

The two major organs involved in the development of Cushing’s syndrome in dogs are the two glandular organs of the endocrine system – the pituitary and the adrenal glands (to be particular, the adrenal cortex). The pituitary is the parent gland that releases Adrenocorticotropin hormone (ACTH) to signal the adrenal cortex to release the stress hormone, cortisol.

Excess of this hormone is the basic cause of Cushing’s syndrome. Excessive levels of cortisol may be caused due to a problem, usually a tumor, with the pituitary or the adrenal gland. When the problem is caused due to a pituitary tumor, it is known as Cushing’s disease.

Regardless of the nature of these tumors, benign or malignant, the result is increase in production of cortisol. Dogs that have previously undergone corticosteroid therapy for allergies or immune diseases are also at a risk of developing symptoms of Cushing’s syndrome.

Cortisol has a strong physiological and chemical effect and acts as an anti-inflammatory and immunosuppressive agent. Large amounts of free circulating cortisol in the body suppress the dog’s immune system, exposing it to various bacterial infections.

Domestication, an increased focus on dog health and veterinarian medicine has led to a situation where pet dogs live longer. Selective breeding to produce individual dog breeds has also led to certain genetic diseases that were not very common before. The practical consequence of this is that dog owners have to deal will more dog diseases than ever before.

Apart from certain dog specific diseases, dogs suffer from practically all diseases experienced by humans. Like humans, dogs to can develop bacterial, fungal and viral infections, skin, orthopedic and eye diseases and tumors and cancers. To add to it all there are diseases associated with old age too. Cushing’s syndrome is one such disorder that is usually seen in older dogs.

Canine Cushing’s syndrome may be endogenous or exogenous. Endogenous Cushing’s is a condition where either of the two main endocrinal glands, the pituitary or the adrenal gland stimulate or produce excessive cortisol within the body. Cortisol is a stress hormone and elevated levels of the hormone depress immune and inflammatory responses. The primary cause of exogenous Cushing’s is the administration of steroid medication.