Effects of weekly blood collection in male and female cynomolgus macaques (Macaca fascicularis).

This study was designed to evaluate the maximal amount of blood that can be safely collected in healthy, adult male and female cynomolgus macaques for 4 consecutive weeks with minimal effect on animal wellbeing. General guidelines for blood collection volumes in laboratory animals are not species-specific, and currently there are few evaluations of blood collection in macaques. In this study, blood was removed at 7.5%, 10%, 12.5%, 15%, or 17.5% of total blood volume (TBV) for 4 consecutive weeks. Hematologic parameters and body weights were evaluated immediately prior to each blood collection time point and for an additional 4 consecutive weeks following the last collection. Male and female macaques tolerated removal of as much as 15% TBV with minor clinical effects, whereas macaques in the 17.5% TBV group exhibited an increased incidence of emesis and anorexia during the first 24 h after blood collection. According to these results, we recommend collecting no more than 15% TBV weekly for 4 consecutive weeks from healthy, adult male and female cynomolgus macaques.