Abstract:
Published haematologic and serum biochemistry reference intervals are very scarce for captive
cheetahs and even more for free-ranging cheetahs. The current study was performed to
establish reference intervals for selected serum biochemistry analytes in cheetahs. Baseline
serum biochemistry analytes were analysed from 66 healthy Namibian cheetahs. Samples
were collected from 30 captive cheetahs at the AfriCat Foundation and 36 free-ranging cheetahs
from central Namibia. The effects of captivity-status, age, sex and haemolysis score on the
tested serum analytes were investigated. The biochemistry analytes that were measured were
sodium, potassium, magnesium, chloride, urea and creatinine. The 90% confidence interval of
the reference limits was obtained using the non-parametric bootstrap method. Reference
intervals were preferentially determined by the non-parametric method and were as
follows: sodium (128 mmol/L – 166 mmol/L), potassium (3.9 mmol/L – 5.2 mmol/L),
magnesium (0.8 mmol/L – 1.2 mmol/L), chloride (97 mmol/L – 130 mmol/L), urea
(8.2 mmol/L – 25.1 mmol/L) and creatinine (88 μmol/L – 288 μmol/L). Reference intervals
from the current study were compared with International Species Information System values
for cheetahs and found to be narrower. Moreover, age, sex and haemolysis score had no
significant effect on the serum analytes in this study. Separate reference intervals for
captive and free-ranging cheetahs were also determined. Captive cheetahs had higher urea
values, most likely due to dietary factors. This study is the first to establish reference
intervals for serum biochemistry analytes in cheetahs according to international guidelines.
These results can be used for future health and disease assessments in both captive and
free-
ranging cheetahs.
