Perioperative socialization, care and monitoring of National Institutes of Health miniature swine undergoing ocular surgery and sampling of peripheral blood

Swine are a frequent species of choice for testing new surgical procedures and for transplantation studies. However, information concerning best practice to prepare pigs for surgery and postoperative treatment and monitoring is limited, despite a perception that preoperative socialization is beneficial. Therefore we examined the effect of preoperative visits by project personnel on compliance of 26 National Institutes of Health (NIH) minipigs subject to corneal transplantation. We briefly describe sedation and anaesthesia protocols developed for surgery and multiple postoperative interventions in order to facilitate interpretation of data relating to pig compliance. Preoperative visit variables and measures of preoperative socialization were correlated with postoperative outcome. Principal component analysis (PCA) of postoperative outcome variables identified a factor accounting for 53.5% of the variance that was significantly associated with two factors derived from PCA of preoperative factors (accounting, respectively, for 54.7% and 26.0% of the variance; P = 0.019 for the overall model, P = 0.041 and 0.040 for factors 1 and 2, respectively), such that more time spent with pigs before surgery and higher socialization scores were associated with less postoperative stress and difficulty of eye medication. Moreover, two of the preoperative visit variables, time spent with only one person in the pen and time spent with two or more people in the pen, contributed predominantly to PCA factors 1 and 2, respectively, indicating that they were fulfilling two qualitatively different requirements for socialization. We conclude that NIH minipigs are fully compliant with anaesthetic and postoperative experimental procedures provided they are well-socialized to project personnel before surgery.