Hematological and Serum Biochemical Reference Intervals for Alphaxalone Sedated Common Marmosets (Callithrix jacchus).

Marmosets are routinely used in biomedical research, therefore there is an increasing need for updated reference intervals calculated using a large sample size, correct statistics, and considering different variables. Hematological and biochemical values from 472 healthy common marmosets sedated with alphaxalone were collected over a ten-year period (2013-2023). The variables assumed to have influenced the blood-based parameters were compared, i.e., sex, age, housing condition, pregnancy, and contraceptive use. Reference intervals were calculated based on observed percentiles without parametric assumptions, and with parametric assumptions following Box-Cox transformation. Juvenile marmosets showed increased ALP, phosphate, WBC, lymphocyte count, and basophil count and decreased levels of GGT and Fe compared to adults. Marmosets housed strictly indoors showed increased ALT and GGT levels and decreased levels of total bilirubin and neutrophil count compared to marmosets housed with outdoor access. Pregnant marmosets showed increased ALP, total bilirubin, neutrophil count, monocyte count, and basophil count, and decreased levels of AST, ALT, cholesterol, Fe, and lymphocyte count compared to non-pregnant marmosets. Etonogestrel contracepted marmosets showed decreased P-LCR compared to females who were not contracepted. Updated reference intervals will aid researchers and veterinarians in identifying physiological and pathological changes, as well as improve the reproducibility of research in this species.

Reference Intervals and Percentiles for Hematologic and Serum Biochemical Values in Captive Bred Rhesus (Macaca mulatta) and Cynomolgus Macaques (Macaca fascicularis).

Several physiological characteristics and housing conditions are known to affect hematologic and serum biochemical values in macaques. However, the studies that have been conducted either report values calculated based on a small number of animals, were designed specifically to document the effect of a particular condition on the normal range of hematologic and serum biochemical values, or used parametric assumptions to calculate hematologic and serum biochemical reference intervals. We conducted a retrospective longitudinal cohort study to estimate reference intervals for hematologic and serum biochemical values in clinically healthy macaques based on observed percentiles without parametric assumptions. Data were obtained as part of the Biomedical Primate Research Centre (Rijswijk, The Netherlands) health monitoring program between 2018 and 2021. In total, 4009 blood samples from 1475 macaques were analyzed with a maximum of one repeat per year per animal. Data were established by species, gender, age, weight-for-height indices, pregnancy, sedation protocol, and housing conditions. Most of the parameters profoundly affected just some hematologic and serum biochemical values. A significant glucose difference was observed between the ketamine and ketamine-medetomidine sedation protocols. The results emphasize the importance of establishing uniform experimental groups with validated animal husbandry and housing conditions to improve the reproducibility of the experiments.