The effects of selected sedatives on basal and stimulated serum cortisol concentrations in healthy dogs

• DOI: 10.7717/peerj.16955
• Publication Date: 2024-02-20T08:10:46Z
• Authors: Adam Hunt; Shelly Olin; Jacqueline C. Whi...; Alejandro Estelle...; Cary Springer; Luca Giori
• Keywords: Cushings; Veterinary Medicine; Hypothalamo-Hypophyseal System; Hypoadrenocorticism; Hydrocortisone; QH301-705.5; Pituitary-Adrenal System; Hyperadrenocorticism; Cortisol; 0403 veterinary science; Dogs; Adrenocorticotropic Hormone; Animals; Hypnotics and Sedatives; Prospective Studies; Biology (General); Addisons; R; 0402 animal and dairy science; Butorphanol; Sedation; Trazodone; Medicine; Deep Sedation; Dexmedetomidine

Background Hormone assessment is typically recommended for awake, unsedated dogs. However, one of the most commonly asked questions from veterinary practitioners to the endocrinology laboratory is how sedation impacts cortisol concentrations and the adrenocorticotropic hormone (ACTH) stimulation test. Butorphanol, dexmedetomidine, and trazodone are common sedatives for dogs, but their impact on the hypothalamic-pituitary-adrenal axis (HPA) is unknown. The objective of this study was to evaluate the effects of butorphanol, dexmedetomidine, and trazodone on serum cortisol concentrations.

Methods Twelve healthy beagles were included in a prospective, randomized, four-period crossover design study with a 7-day washout. ACTH stimulation test results were determined after saline (0.5 mL IV), butorphanol (0.3 mg/kg IV), dexmedetomidine (4 µg/kg IV), and trazodone (3–5 mg/kg PO) administration.

Results Compared to saline, butorphanol increased basal (median 11.75 µg/dL (range 2.50–23.00) (324.13 nmol/L; range 68.97–634.48) vs 1.27 µg/dL (0.74–2.10) (35.03 nmol/L; 20.41–57.93); P < 0.0001) and post-ACTH cortisol concentrations (17.05 µg/dL (12.40–26.00) (470.34 nmol/L; 342.07–717.24) vs 13.75 µg/dL (10.00–18.90) (379.31 nmol/L; 275.96–521.38); P ≤ 0.0001). Dexmedetomidine and trazodone did not significantly affect basal (1.55 µg/dL (range 0.75–1.55) (42.76 nmol/L; 20.69–42.76); P = 0.33 and 0.79 µg/dL (range 0.69–1.89) (21.79 nmol/L; 19.03–52.14); P = 0.13, respectively, vs saline 1.27 (0.74–2.10) (35.03 nmol/L; 20.41–57.93)) or post-ACTH cortisol concentrations (14.35 µg/dL (range 10.70–18.00) (395.86 nmol/L; 295.17–496.55); (P = 0.98 and 12.90 µg/dL (range 8.94–17.40) (355.86 nmol/L; 246.62–480); P = 0.65), respectively, vs saline 13.75 µg/dL (10.00–18.60) (379.31 nmol/L; 275.86–513.10).

Conclusion Butorphanol administration should be avoided prior to ACTH stimulation testing in dogs. Further evaluation of dexmedetomidine and trazodone’s effects on adrenocortical hormone testing in dogs suspected of HPA derangements is warranted to confirm they do not impact clinical diagnosis.