Pretreatment clinical and laboratory findings in dogs with hypoadrenocorticism: 225 cases (1979-1993)

hypoadrenocorticism is a rare disease in dogs, most commonly affecting young to middle-aged females; some breeds are at greater risk of developing the disease than others. In general, clinical signs are nonspecific and similar to manifestations of more common diseases. Serum electrolyte disturbances of hyperkalemia and hypernatremia are characteristic in dogs with primary hypoadrenocorticism, but concentrations may be normal in dogs with early or mild primary or secondary hypoadrenocorticism. Diagnosis of hypoadrenocorticism is best confirmed by demonstration of a low baseline serum cortisol concentration with a subnormal or negligible response to ACTH administration. Determination of endogenous plasma ACTH concentrations is valuable in differentiating primary from secondary hypoadrenocorticism, particularly in dogs with normal serum electrolyte concentrations.