Normal sonographic anatomy of the abdomen of coatis (Nasua nasua Linnaeus 1766)

Abstract

Background: The use of ultrasound in veterinary medicine is widespread as a diagnostic supplement in the clinical routine of small animals, but there are few reports in wild animals. The objective of this study was to describe the anatomy, topography and abdominal sonographic features of coatis.

Results: The urinary bladder wall measured 0.11 ± 0.03 cm. The symmetrical kidneys were in the left and right cranial quadrant of the abdomen and the cortical, medullary and renal pelvis regions were recognized and in all sections. The medullary rim sign was visualized in the left kidney of two coatis. The liver had homogeneous texture and was in the cranial abdomen under the rib cage. The gallbladder, rounded and filled with anechoic content was visualized in all coatis, to the right of the midline. The spleen was identified in the left cranial abdomen following the greater curvature of the stomach. The parenchyma was homogeneous and hyperechogenic compared to the liver and kidney cortex. The stomach was in the cranial abdomen, limited cranially by the liver and caudo-laterally by the spleen. The left adrenal glands of five coatis were seen in the cranial pole of the left kidney showing hypoechogenic parenchyma without distinction of cortex and medulla. The pancreas was visualized in only two coatis. The left ovary (0.92 cm x 0.56 cm) was visualized on a single coati in the caudal pole of the kidney. The uterus, right adrenal, right ovary and intestines were not visualized.

Conclusions: Ultrasound examination of the abdomen of coatis may be accomplished by following the recommendations for dogs and cats. It is possible to evaluate the anatomical and topographical relationships of the abdominal organs together with the knowledge of the peculiarities of parenchymal echogenicity and echotexture of the viscera.

Figure 1

Transverse sonogram of the urinary bladder of an adult male Coati. A) Urinary bladder filled with anechoic urine content in usual topography, ventral to the descending colon (CD). B) Magnified image for detail of the urinary bladder wall, 1 – serosal layer (hyperechoic), 2 - muscular layer (hypoechoic), 3 - submucosal layer (hyperechoic).

Figure 2

Transverse sonogram of the left ovary (between cursors) of an adult Coati. An central circular anechoic area (1) indicates a cyst. RE, left kidney.

Figure 3

Sonogram of the kidneys of an adult Coati. Kidney in sagittal (A), dorsal (B and D) and transverse (C) planes. Observe the indication of the cortical (C), medullary (M), renal pelvis (P) and diverticulum (D).

Figure 4

Sonogram of the liver in longitudinal section an adult Coati. A) Anatomic relationship of hepatic sublobe and stomach. Gallbladder is visible having a teardrop shape, filled with anechoic homogeneous content and a thin hyperechoic wall. B) Anatomic relationship of the caudate sublobe with the right kidney. C) Identification of the portal vein with hyperechoic walls (1) and hepatic veins with isoechoic walls (2). A) Acoustic shadowing due to the presence of a rib can be seen in all images (S).

Figure 5

Sonogram of the spleen in longitudinal section an adult Coati. The hyperechoic capsule (1) and the cranial end to the greater stomach curvature were observed and the echogenicity relationship between the hyperechoic spleen (A) with the less echogenic renal cortex, and the liver which is isoechoic in relation to the renal cortex (B). BA, spleen, ES, stomach, FG, liver, RD, right kidney. Acoustic shadowing due to the presence of ribs (S).

Figure 6

Sonogram of the adrenal and pancreas in an adult Coati. A) Left adrenal left in longitudinal section (between cursors), note the relationship to the cranial pole of the left kidney, B) Left adrenal in transverse section (between cursors), keeping the anatomical relationship with the left kidney in transverse section. RE, left kidney. Pancreas, hypoechoic in relation to adjacent tissues. Between arrows in C) and adjacent to duodenum (DUO) in D).

Figure 7

Sonogram of the gastrointestinal tract in an adult Coati. Anatomical relationship of the stomach with the liver (A) and spleen (B). Measurement of the intestinal wall in the longitudinal section shown between cursors (C). Measurement of the gastric wall in longitudinal section indicated between cursors (D). In detail, the layers of the intestinal wall, 1- serosal and subserosal layer (hyperechogenic), 2 – muscularis (hypoechogenic), 3 - submucosa (hyperechogenic), 4 - mucosa (hypoechogenic), 5 - lumen (hyperechogenic). FG, liver, ES, stomach, BA, spleen, RE, left kidney.