Analysis of serum biomarkers associated with pain in Spanish greyhounds undergoing ovariohysterectomy.

BACKGROUND

This study measured serum biomarkers at baseline and during an ovariohysterectomy in healthy female Spanish greyhounds, aiming to enhance the objectivity of current methods for assessing acute postoperative pain in dogs.

METHODS

Blood samples from 20 Spanish greyhounds were collected before drug administration (T0-baseline). Premedication included dexmedetomidine and methadone, followed by propofol and isoflurane. Four additional samples were taken: post-second ovariectomy (T1-PostOvary), 4 hours post-premedication (T2-PreRescue), 30 minutes post-rescue methadone (T3-PostRescue) and 24 hours post-extubation (T4-24H). Biomarkers were quantified via ELISA, and postoperative pain was assessed using the short-form Glasgow scale (Glasgow-SF). Data analysis included ANOVA, Friedman test and Spearman's correlation.

RESULTS

Glutamate (p = 0.007; Kendall's W = 0.186) and calcitonin gene-related peptide (CGRP) (p = 0.001; η p 2 $\eta _p^2$ = 0.324) peaked at T0-baseline. Cortisol peaked at T3-PostRescue (p = 0.041; η p 2 $\eta _p^2$ = 0.099). Glasgow-SF scores increased postoperatively compared with T0-baseline (p = 0.001; Kendall's W = 0.612), without significant biomarker correlation.

LIMITATIONS: Sample homogeneity may limit result generalisability and lack of acclimatisation may introduce bias, as initial stress could affect the synthesis of stress-related biomarkers.

CONCLUSIONS

Although glutamate, CGRP and cortisol levels fluctuated over time-with glutamate and CGRP peaking at T0-baseline-none proved useful for assessing postoperative pain compared with conventional clinical parameters.