DETERMINATION OF SYMMETRIC DIMETHYLARGININE, CREATININE, AND BLOOD UREA NITROGEN REFERENCE INTERVALS IN AFRICAN WILD DOGS (LYCAON PICTUS) IN MANAGED CARE FROM TWO ZOOLOGICAL INSTITUTIONS IN THE UNITED KINGDOM.

Abstract

The African wild dog (AWD; Lycaon pictus) is an endangered canid from sub-Saharan Africa. Ex situ global conservation efforts include captive breeding and maintenance of healthy individuals in zoos to create insurance populations and maintain genetic diversity. Chronic renal disease (CRD) has been identified as a comorbidity at necropsy in zoo-housed adult and geriatric AWDs. Symmetric dimethylarginine (SDMA) is a renal biomarker that has been widely used for the early diagnosis of CRD. There are no published reference intervals (RIs) for SDMA and conventional nonspecific renal biomarkers, such as creatinine and blood urea nitrogen (BUN) in AWDs. Banked frozen sera collected from 35 healthy AWDs between 2000 and 2020 from two United Kingdom zoos were used to establish RIs using the parametric method. The RIs were: SDMA (2.48-15.7 µg/dl), creatinine (0.67-1.69 mg/dl), and BUN (13.87-39.34 mg/dl). SDMA showed a significant positive correlation with serum creatinine (Pearson's test, r = 0.41; P = 0.02). An independent t test and a one-way ANOVA showed no significant differences between age and sex on the analytes, but mean SDMA levels were higher in younger animals. The RIs determined in this study will help refine the diagnosis and monitoring of CRD in zoo-housed AWDs.