Urinary corticoids in the diagnosis of canine hyperadrenocorticism

In 20 healthy experimental dogs the 24 hour urinary corticoid excretion as measured by cortisol radioimmunoassay on two consecutive days varied from 0.5 to 3.3 nmol/kg/24 hours and from 0.3 to 3.6 nmol/kg/24 hours. In 20 dogs with otherwise proven spontaneous hyperadrenocorticism these values varied from 4.4 to 35.7 nmol/kg/24 hours and from 3.6 to 26.8 nmol/kg/24 hours respectively. Corticoid/creatinine ratios in morning urine samples of 28 healthy pet dogs were 1.2 to 6.9 X 10(-6). In 27 dogs with spontaneous hyperadrenocorticism all ratios exceeded the range observed in the healthy pet dogs.