T. Yanai et al., SUBCLINICAL RENAL OXALOSIS IN WILD-CAUGHT JAPANESE MACAQUES (MACACA-FUSCATA), Journal of Comparative Pathology, 112(2), 1995, pp. 127-131
Various degrees of crystal deposition were found in the kidneys of 12
out of 59 Japanese macaques (Macaca fuscata) caught in the wild in Gif
u, Japan. The needle- or rod-shaped crystals, which were radially arra
nged and occurred in the lumen and epithelium of the renal (mainly the
proximal) tubules, were birefringent under polarized light. They stai
ned with alizarin red S at a pH of 7.0 but not 4.2, and were identifie
d as calcium oxalate. The morphological features of the renal lesions
were similar to those previously reported in oxalate poisoning, and it
was believed that the macaques ingested the oxalate in plants.