The goals of this study were to evaluate changes in gastrointestinal parameters, physiologic variables, and electronic von Frey (EVF) mechanical thresholds following routine orchiectomy to determine if these parameters can serve as appropriate, repeatable criteria to monitor postoperative changes in guinea pigs. A randomized, double-blinded study was performed with 14 intact male guinea pigs. All guinea pigs underwent routine orchiectomy and were randomly assigned to 1 of 2 postoperative treatment groups. Each guinea pig received meloxicam 0.5 mg/kg subcutaneously and buprenorphine 0.03 mg/kg subcutaneously immediately following surgery. They were then administered either: meloxicam 0.5 mg/kg subcutaneously at 24 and 48 hours postoperatively (meloxicam group) or saline subcutaneously at 24 and 48 hours postoperatively (control group). Basic physiologic parameters (heart rate, respiratory rate, rectal temperature, and body weight), urine and fecal output, food and water consumption, and EVF mechanical thresholds around incision sites were recorded for 48 hours preoperatively and postoperatively. Significant increases in heart rate and rectal temperature and significant decreases in respiratory rate, body weight, and EVF mechanical thresholds were identified postoperatively in both treatment groups. Significant decreases in consumption were noted postoperatively in both treatment groups, but no change in fecal or urine output was identified. Most of these values were easily obtained and showed significant changes from preoperative values in both study groups.