Small Animal Internal Medicine
Morgan Brown, BVM&S, MRCVS (she/her/hers)
Small Animal Internal Medicine Resident
Auburn University College of Veterinary Medicine
Auburn, Alabama, United States
Abstract:
Introduction. Conditions affecting the hypothalamic-pituitary-adrenal (HPA) axis are common in dogs. Testing the function of the HPA axis includes measurement of endogenous adrenocorticotropic hormone (eACTH) and/or adrenocorticotropic hormone (ACTH) stimulation test. Trazodone is an anxiolytic commonly administered to dogs to reduce stress. In humans, trazodone significantly decreases plasma cortisol concentration via alpha-1 adrenergic activity. The aims of this study were to determine the impact of trazodone on eACTH and serum cortisol concentrations in healthy dogs.
Animals. Fourteen healthy, adult, privately-owned dogs were prospectively enrolled.
Methods. Randomized placebo-controlled study. Trazodone (8-10mg/kg) or placebo was administered orally 1 hour prior to eACTH measurement and ACTH stimulation testing. After a ≥7-day wash-out, dogs received the opposite treatment. Differences in eACTH, pre- and post-ACTH stimulation cortisol levels, and delta (difference between pre- and post-ACTH) cortisol concentrations were analyzed using a Paired T or Signed Rank Test with a p < 0.05 significance level.
Results. The eACTH concentrations were not significantly different (p=0.233) between treatments. Similarly, no significant differences were found in the pre-ACTH cortisol concentrations between treatments (p=0.401). There was a significant difference between treatments for post-ACTH cortisol concentrations (p=0.049) and delta cortisol concentrations (p=0.042). Two dogs receiving trazodone had post-ACTH cortisol concentrations below the reference range compared to no dogs receiving placebo.
Conclusions and clinical importance. Preliminary data suggest trazodone administration may dampen the adrenocortical response to stimulation in healthy dogs. If similar effects are found in dogs with hyper- or hypo- adrenocorticism, use of trazodone may impact clinical decision making in these populations.
