Arginine vasopressin, ghrelin, 5-hydroxyindoleacetic acid, and substance P do not appear to be reliable biomarkers of nausea in dogs

Abstract

Objective: To determine if ACTH, cortisol, arginine vasopressin (AVP), ghrelin, 5-hydroxyindoleacetic acid (5-HIAA), and substance P (SP) blood biomarkers associated with nausea in humans have similar associations in dogs. Methods: 7 healthy, mixed hound dogs were nausea scored using videotaped observations, and concentrations of ACTH, cortisol, AVP, ghrelin, 5-HIAA, and SP were measured in blood at baseline, after 0.5 mg/kg, IM, morphine administration, and following administration of the treatment drug. Data collection occurred from October 20 through November 24, 2023. Treatments were saline 0.1 mL/kg (S) and propofol 0.5 mg/kg (P1), 1.0 mg/kg (P2), and 1.5 mg/kg (P3) administered IV 20 minutes after morphine administration using a randomized, crossover design with a 7-day washout between treatments. Results: Nausea scores increased at 5 minutes and over time in all treatments. Adrenocorticotropic hormone concentrations were lower in P2 versus P1, P2 versus S, and P3 versus S at the 50-minute time point. At 50 minutes, cortisol concentrations were lower in P3 versus S, P2 versus S, and P3 versus P1. There were no statistically significant differences in AVP, ghrelin, 5-HIAA, or SP concentrations between treatments or over time. Conclusions: AVP, ghrelin, 5-HIAA, and SP did not correlate with nausea signs in dogs. Additionally, propofol, at the subhypnotic doses administered, did not significantly decrease signs of nausea. Clinical Relevance: ACTH and cortisol, but not AVP, ghrelin, 5-HIAA, and SP, concentrations appeared to be associated with signs of nausea in dogs. Propofol was not effective at decreasing signs of nausea at the administered dosages.