Dimensions and skeletopy of kidneys in two populations of Cerdocyon thous (Linnaeus, 1766)

Abstract

Cerdocyon thous is the South American canid with great geographic distribution. To the south of Ecuador, two isolated populations have been identified, living in different average temperatures and food availability. The objective was to measure the length, width, thickness and volume of the kidneys, length of renal vessels, and verify the renal skeletopy in two populations of C. thous. Kidneys and renal vessels were measured from 34 cadavers collected on highways in the Brazilian territory. From the Atlantic Forest biome (latitude 22º), 14 specimens (seven males and seven female) were analyzed, and from the Pampa biome (latitude 29º), 20 specimens (eight males and twelve female). On average, in the right antimere the kidneys measured 49.9 ´ 25.2 ´ 24.4 mm, had a volume of 16.5 cm³, the renal artery measured 21.3 mm and the renal vein 19.4 mm. In the left antimere, the kidneys measured 49.3 ´ 24.4 ´ 22.8 mm, with a  volume of 14.6 cm³ and the artery and vein measured 21.0 mm and 28.4 mm, respectively. The right kidney was always cranial and predominantly positioned ventrally to vertebrae L1–L3, while the left one was positioned ventrally to vertebrae L2–L4. There was no difference in the comparison between sexes or antimeres. Most renal dimensions were significantly higher in the specimens from the Pampa biome, possibly due to the body size and type of diet. This result warns of interpreting diagnoses that depend on the evaluation of the normal renal dimensions in this species.