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Evaluating Postoperative Parameters in Guinea Pigs (Cavia porcellus) Following Routine Orchiectomy

https://doi.org/10.1053/j.jepm.2016.04.009Get rights and content

Abstract

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.

Section snippets

Animals

This study was approved through the University of California, Davis Institutional Animal Care and Use Committee (protocol #16783). In total, 14 intact male, 9- to 10-month-old Duncan-Hartley guinea pigs ranging in body weight from 0.874 to 1.267 kg were used for this study. The guinea pigs were purchased from a commercial laboratory vendor. Their health was assessed via physical examination with no overt signs of clinical disease being identified. On arrival, all guinea pigs were numerically

Results

A guinea pig from the meloxicam group died during recovery from anesthesia; however, a complete postmortem examination (gross and histopathology) did not provide a cause for the guinea pigs death. Data from this subject were excluded and a total of 13 guinea pigs (meloxicam group n = 6; control group n = 7) were then included for all analyses.

Hay (P = 0.015), pellet (P < 0.001), and water (P = 0.002) consumption (Fig. 1) decreased significantly postoperatively when compared to the preoperative

Discussion

This study was developed to evaluate criteria for assessing postoperative behavioral changes in male guinea pigs postorchiectomy after the use of 1 of 2 postoperative analgesic treatment protocols. Significant changes occurred in vital parameters, consumption, and EVF mechanical thresholds postoperatively in all animals regardless of group. Although these changes are significant and may suggest some degree of postoperative pain and discomfort, there are some fundamental limitations of this

Acknowledgments

We would like to thank the Silicon Valley Foundation for their financial support of this study and Dr. Peter Pascoe for the use of the EVF filaments.

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