THE USE OF SALIVA CORTISOL, URINARY CORTISOL, AND CATECHOLAMINE MEASUREMENTS FOR A NONINVASIVE ASSESSMENT OF STRESS RESPONSES IN DOGS

A problem in assessing animal welfare is that collecting data in itsel f may be stressful to the animals. Therefore, noninvasive methods for collecting data have to be devised and tested. A first step in investi gating saliva cortisol, urinary cortisol, and urinary catecholamine as noninvasive indicators of canine well-being is the validation of thes e hormonal measures as alternatives for those in plasma. Using a model of insulin (0.2 U/kg)-induced hypoglycemia, we report on stress-induc ed responses in saliva cortisol, urinary cortisol, and urinary catacho lamines relative to cortisol and catecholamine responses in plasma. Hy poglycemia in six dogs induced significant (P < 0.05) increases in pla sma cortisol and adrenaline but not noradrenaline. Saliva cortisol res ponses expressed as net area under the response curve correlated signi ficantly with plasma cortisol responses (r > 0.92). Saliva cortisol le vels measured 7 to 12% of plasma cortisol concentrations. Cortisol/cre atinine ratios in urine were significantly higher when voided after in sulin administeration, compared to when voided after saline treatment. insulin-induced increments in cortisol/creatinine ratios were nonsign ificant when urine samples were assayed after dichloromethane extracti on. Although urinary adrenaline/creatinine (A/C) ratios were significa ntly correlated with maximum plasma adrenaline values after insulin ad ministration, A/C ratios did not differ significantly between insulin and saline treatment. The present experiment provides strong support f or using saliva sampling and urine collection as noninvasive methods t o establish stress-induced cortisol responses. For measuring acute pla sma adrenaline responses, measuring A/C ratios may not be a valid alte rnative. (C) 1996 Academic Press, Inc.