Cortisol concentrations following stimulation of healthy and adrenopathic dogs with two doses of tetracosactrin

A prospective study was undertaken to compare intravenous tetracosactrin at doses of 5 mu g/kg and 250 mu g for diagnosing hyperadrenocorticism in dog s. Both healthy dogs and dogs with pituitary-dependent hyperadrenocorticism were evaluated with the two doses of the drug, and serum cortisol concentr ations were compared at 60 minutes post-stimulation. Some of the dogs had a dditional samples taken at 90 and 120 minutes. For four dogs with hyperadre nocorticism, timed samples were also obtained at 150, 180 and 240 minutes p ost-injection. Cortisol concentrations 60 minutes after stimulation with ei ther 5 mu g/kg or 250 mu g intravenous tetracosactrin were similar for both healthy dogs and dogs with hyperadrenocorticism. The lower dose can theref ore be used for diagnosing hyperadrenocorticism in dogs.