Calcium salt crystalluria in a captive chimpanzee (Pan troglodytes) population

Abstract

Urinalysis is a standardized method of health monitoring in captive and wild chimpanzees (Pan troglodytes), as urine collection is noninvasive in nature and provides a significant amount of information about an individual's health. [1][2][3][4] Dipstick analysis and refractometry are feasible to perform in the field; however, it is more difficult to perform a urine sediment analysis outside of a hospital setting due to the equipment required and the time limitation on analyzing the sample. For this reason, sediment analysis is often not included in papers investigating primate urine samples.Microscopic crystalluria is identified during the urine sediment analysis portion of a urinalysis. While crystalluria can be benign or normal in herbivores, 5,6 it can also indicate kidney dysfunction, pH imbalance, or various toxicities. [5][6][7] Furthermore, crystalluria can cause disease due to renal mineralization, 6,7 or result in pathological nephrolithiasis or urolithiasis. 6 Renal disease is the second most common cause of morbidity and mortality in captive chimpanzees, 8,9 surpassed only by cardiac disease. 9 Renal disease has also been linked to various cardiac pathologies in humans 9 ; therefore, it is important to note the presence of crystalluria in chimpanzees so that further exploration of renal and cardiac function can be performed.This study explores calcium salt crystalluria in a captive chimpanzee population and analyzes the differences between samples with and without crystalluria. It also discusses the possible effects of diet and various medications on the occurrence of crystalluria.