Impact of an auditory stimulus on baseline cortisol concentrations in clinically normal dogs.
Academic Article
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
Baseline cortisol concentrations are routinely used to screen dogs for hypoadrenocorticism (HOC); this diagnosis must then be confirmed with an ACTH stimulation test. A baseline cortisol concentration less than 55nmol/L (2g/dL) is highly sensitive for HOC but lacks specificity, with a false positive rate >20%. Many dogs with nonadrenal disease are therefore subjected to unnecessary additional testing. It was hypothesized that exposure to an unpleasant auditory stimulus before sample collection would improve the specificity of baseline cortisol measurements in dogs with nonadrenal disease by triggering cortisol production. Twenty-eight healthy client-owned dogs were included in the study, with a median age of 4yr (range 2-9yr) and a median weight of 20kg (range 10-27kg). Dogs were ineligible for inclusion if they had received short- or long-acting glucocorticoids within the previous 30 and 90d, respectively. Dogs were randomly assigned to group 1 (control; no noise; n = 7), group 2 (brief noise: n = 10), or group 3 (long noise: n = 11). Each dog and owner were directed to a secluded area for approximately 15min. Group 1 sat in relative quiet, exposed only to the background sounds of a veterinary hospital. Group 2 were exposed to the sound of a wet-dry vacuum in an adjacent hallway during the first 3min of this period. Group 3 were exposed to random bursts of wet-dry vacuum noise during this period. At the end of the test interval, each dog was escorted to an adjacent examination room for blood collection. Samples were processed within 15min; serum was frozen at -80C before measurement of cortisol concentrations. Median serum cortisol concentrations and the proportion of dogs with results <55nmol/L were similar for the 3 groups. The study hypothesis that exposure to the noise of a wet-dry vacuum cleaner would consistently drive baseline serum cortisol concentrations above 55nmol/L in dogs with apparently normal adrenal function was therefore rejected.
