Comparison of 2 ACTH Stimulation Tests in Determining Adrenal Function in Critically Ill Dogs

Use of low-dose ACTH stimulation testing may be important in diagnosing mild degrees of adrenocortical insufficiency and a new syndrome, critical illness-related corticosteroid insufficiency (formerly known as relative adrenal insufficiency), which has been recognized in critically ill human and veterinary patients. Both 0.5 and 5 μg/kg doses of cosyntropin cause maximal adrenal stimulation with regard to serum cortisol concentrations in healthy dogs. The purpose of this study was to determine if low-dose ACTH stimulation testing was as accurate as standard-dose ACTH stimulation testing in determining adrenal function in critically ill dogs.

Results

Cosyntropin administered at a dose of 0.5 μg/kg IV appears to be at least as accurate as the administration of 5 μg/kg cosyntropin in determining adrenal function in critically ill dogs. In fact, the low-dose ACTH stimulation test may be more sensitive in detecting mild degrees of adrenal insufficiency in ill dogs.

Co-sponsored with the Morris Animal Foundation, Grant Number: D06CA-050

Dr. Linda G. Martin, DVM, MS, DACVECC
Washington State University