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

## TL;DR

This study provides updated blood and serum reference ranges for common marmosets sedated with alphaxalone, considering factors like age, sex, and housing.

## Contribution

The study establishes comprehensive reference intervals for marmosets across life stages, including pregnancy and contraception, using a large dataset.

## Key findings

- Juvenile marmosets had higher ALP, phosphate, and WBC compared to adults.
- Marmosets housed indoors showed higher ALT and GGT levels than those with outdoor access.
- Pregnant marmosets had increased ALP and bilirubin but lower AST and cholesterol.

## Abstract

In the present study, hematological and serum biochemical reference intervals were established for common marmosets sedated with alphaxalone through all life stages, including pregnancy and contraception. Clinically relevant changes were established for multiple parameters when comparing data based on age, sex, housing condition, contraceptive use, and pregnancy. The availability of updated reference intervals, calculated using a large sample size and using the appropriate statistical methods, is an essential part of providing optimum care and support to marmosets used in biomedical research.

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.