ON THE CANINE CUSHINGS-SYNDROME - SURVEY- 1 - PATHOPHYSIOLOGY AND SYMPTOMS OF THE HYPERADRENOCORTICISM - SURVEY-2 - DIAGNOSIS AND THERAPY OF THE HYPERADRENOCORTICISM

Based on literature data, pathophysiology, clinical signs, diagnosis a nd treatment of one of the most frequently observed endocrinopathy in dogs - hyperadrenocorticism - has been summarized. The Canine Gushing' s Syndrome (CCS) is due to pituitary-dependent hyperadrenocorticism (P DH) in 80 to 85% and adrenal tumor hyperadrenocorticism (ATH) in 15 to 20% of all the cases, respectively. It can also owing to hormone prod ucing tumor caused by ectopic ACTH overproduction or by iatrogenic CCS . Characteristic features of the disease observed in any breeds and - first of all - in medium aged and older dogs are, as follows: polyuria /polydipsia, polyphagia, lethargy, pendulous abdomen (Fig. 1), myasthe nia, alopecia, skin atrophy (Fig. 2), development of comedos (Fig. 3), calcinosis cutis (Fig. 4), as well as reproductive biological disorde rs. Investigation of urine and blood revealed many non-specific altera tions. Hyperadrenocorticism can be suspected according to the clinical symptoms, biochemical investigations and screening tests. Diagnosis o f the disease is carried out by the determination of cortisol concentr ation by RIA, ELISA, HPLC or ELA following ACTH stimulation test and l ow-dose dexamethasone suppression (LDDS) test. To select an appropriat e therapy, differentiation of hyperadrenocorticism of hypophysic or ad renocortical origin can be done by high-dose dexamethasone suppression (HDDS) test, determination of ACTH concentration, UH, CT and scintigr aphic investigations. Treatment of hyperadrenocorticism can be carried out by definite destruction of cortisol-producing areas in the adrena l cortex, reversible suspension of its function or surgical removal of adrenal cortex or hypophysis containing the hormone-producing tumor. The most frequently used preparation is Lysodren (mitotane).