Morphometry and skeletopy of kidneys and renal vessels in “ring-tailed coati” (Nasua nasua)

Abstract

Nasua nasua is a carnivore belonging to the family Procyonidae and is widely distributed throughout South America. The details of its anatomy are fundamental to the application of antomy and understanding of its natural history. This study aimed to measure the average length, width, thickness, and volume of the kidneys; the average length of the renal artery and vein, and to describe the renal and vessel skeletopy in Nasua nasua. For this purpose, 32 kidneys and renal vessels of 16 cadaveric specimens (eight male and eight female) were dissected and measured using a digital caliper. Pearson's correlation coefficients were calculated between the rostrum-sacral length and the renal and vessel variables. The kidneys had a “bean-shaped” aspect with smooth surfaces and were unipapilate. On average, the N. nasua kidneys measured 30 × 16 × 13 mm, with no significant difference between the sexes. The average right renal artery (1.74 ± 0.67 cm) was longer than the left (1.26 ± 0.43 cm), and the right renal vein (1.22 ± 0.34 cm) was shorter than the left renal vein (1.82 ± 0.46 cm) (p < 0.05). One male animal (6.8%) presented with a double right renal vein as an anatomical variation. Both the right and left kidney cranial poles prevailed at the level of the L2 vertebra, assuming a practically symmetrical position. There was a positive and moderate to high correlation between rostrum-sacral length and renal dimensions and renal vessel lengths. The present data may be useful for interpreting the diagnosis of nephropathies that affect renal dimensions in this species and may contribute to the comparative anatomy of carnivorans.