Hyperadrenocorticism or Cushing's syndrome in dogs.

Hyperadrenocorticism is the most common endocrinopathy in dogs and is almost never seen in cats.

It is a condition caused by a chronic excess of the hormone cortisol in the blood. Cortisol is a glucocorticoid steroid hormone produced by the adrenal cortex under the influence of adrenocorticotropic hormone (pituitary hormone).

Causes of hyperadrenocorticism in dogs:

- Iatrogenic hyperadrenocorticism (caused by prolonged use of synthetic analogues of glucocorticoid hormones - prednisolone, dexamethasone, methipred, dexafort, etc.) These drugs are often used in the treatment of allergic skin diseases, some immune-mediated diseases (e.g., immune-mediated hemolytic anemia)

- pituitary tumor (85-90% of all cases). The tumor produces excessive amounts of adrenocorticotropic hormone (ACTH), which in turn stimulates the adrenal glands to produce cortisol. In the case of active tumor growth, dogs may show neurological symptoms due to the tumor compressing the surrounding tissues.

- Tumors of the adrenal glands. Tumors can be benign or malignant. In the case of a benign tumor, surgery can help to cope with the disease, while in the case of a confirmed malignant tumor, the prognosis is more unfavorable.

The most common signs of Cushing's syndrome in dogs are:

- polyuria/polydipsia (increased thirst and urination)

- hair loss and lack of hair growth

- thin and fragile skin, calcification

- polyphagia (increased appetite)

- weight loss, abdominal enlargement

- lethargy

- hypertension

- absence of heat in bitches, testicular atrophy in dogs

Often, dog owners mistake these symptoms as signs of aging in their pet.

Laboratory changes in blood tests include neutrophilia, monocytosis, lymphopenia, and eosinopenia. The most common abnormality in blood chemistry is an increase in alkaline phosphatase. Due to the direct effect of cortisol on hepatocytes, ALT and AST levels increase.

Excessive cortisol induces lipolysis, which increases serum cholesterol and triglyceride levels. Cortisol is also a counterinsulin hormone, which can lead to a moderate increase in glucose, and as a result, dogs may show symptoms of diabetes.

Diagnosis of hyperadrenocorticism:

- Urinary Cortisol/Creatinine Ratio
Because of its high sensitivity and low specificity, a negative result is very useful in ruling out hyperadrenocorticism, but an elevated result requires further testing to confirm the diagnosis. The test is convenient because it requires only a urine sample and does not require hospitalization, since stress is assumed to cause false elevations in urinary cortisol levels, it is recommended to collect a sample at home in a stress-free environment.

- Small dexamethasone test

- ACTH (adrenocorticotropic hormone) test

- Abdominal ultrasound, blood tests, and urinalysis can also be part of the diagnostic process. They are necessary for better control of the disease and prognosis.

What are the treatment options?

Treatment depends on the cause of the disease. The goal of treatment is to improve the pet's quality of life and suppress the symptoms of hyperadrenocorticism. The preferred treatment for hyperadrenocorticism caused by an adrenal tumor is adrenalectomy. In case of confirmed pituitary hyperadrenocorticism, drug therapy is prescribed. If the pituitary tumor increases in size and leads to neurological disorders, such patients should consider surgical removal of the tumor.

In our clinic, you can conduct a complete diagnosis of your pet, as well as get an endocrinologist's advice on treatment and management of the disease. Thanks to the full range of laboratory equipment in the clinic, hormone testing is carried out promptly, on the day of the test, which guarantees a quick diagnosis.