ULTRASONOGRAPHY OF THE LIVER, SPLEEN, AND URINARY TRACT OF THE CHEETAH (ACINONYX JUBATUS)

Abstract

Diseases of the abdomen of the cheetah (Acinonyx jubatus) include those affecting the liver, spleen, and urinary tract. The most common diseases of captive-bred cheetah are gastritis, gastric ulceration, glomerulosclerosis, and hepatic veno-occlusive disease, and are the most frequent causes of mortality in these animals. The purpose of this study was to describe the ultrasonographic anatomy of the normal liver, spleen, kidney, and urinary bladder of the anesthetized captive-bred cheetah. Twenty-one cheetahs were examined. Eight of the 21 animals had subclinical evidence of either gastritis or chronic renal disease. The ultrasonographic appearances of the liver, gall bladder, common bile duct, and spleen were evaluated and various measurements made. Statistical analyses of the measurements were performed on all the healthy and subclinically ill animals taking sex, age, mass, and anesthetic protocol into account. There were no significant differences in any parameters between the healthy and subclinically ill animals (P > 0.25) and data were combined for statistical analyses. The mean mass was 41.1kg ( +/- 8.8) and the mean age was 5.0 years (+/- 2.2). The mean thickness of the liver medial to the gall bladder was 67.0 mm (+/- 14.8) and the liver was within the left costal arch in 75% of animals, extended caudal to the right costal arch in 50% of animals for an average of 30 mm, and extended caudal to the sternum in 63% of animals for an average of 32.5 mm. The maximum mean hepatic vein diameter at the entrance to the caudal vena cava was 8.6 +/- 2.8 mm; the mean diameters of the portal vein at the hilus and that of the caudal vena cava as it entered the liver were 7.5 +/- 1.6 and 9.9 +/- 4.1 mm, respectively. The mean diameter of the caudal vena cava was significantly affected by the type of anesthetic used (P < 0.10). The mass of the animals was significant in explaining the variance in maximum portal vein diameters (P < 0.10). The mean maximum velocity of the hepatic vein flow at the entrance to the caudal vena cava was 25.3 +/- 2.8 cm/s (n=4), the hilar portal vein was 11.7 +/- 3.3 cm/s (n=7), and the caudal vena cava was 33.8 +/- 19.8 cm/s (n=5). The mean maximum gall bladder length and width, and the mean common bile duct diameters were 44.6 mm (+/- 10.4), 23.3 mm (+/- 5.0), and 8.1 mm (+/- 2.4), respectively. Age was significant in explaining the variance in gall bladder lengths (P<0.10). Urinary tract ultrasonography was performed only in animals that had normal urea and creatinine levels (n=13). Renal cortico-medullary distinction was present in all kidneys and a cortico-medullary rim sign was seen in 21 of 26 kidneys. Mean kidney length, height, and width was 63.9 +/- 5.7, 38.1 +/- 5.2, and 42.1 +/- 5 mm, respectively. The average resistivity index was 0.58 (n=5). Mean urinary bladder length, height, and width were 57.0, 19.2, and 34.9 mm, respectively.

ULTRASONOGRAPHIC ABDOMINAL ANATOMY OF HEALTHY CAPTIVE CARACALS (CARACAL CARACAL)

“…The echogenicity of the spleen, mostly hyperechoic in relation to the liver and renal cortices, was observed in this study and also has been observed in cheetahs (Acinonyx jubatus) 4 and domestic cats and dogs. 12 The triangular-shaped spleen surrounded by a thin smooth echogenic capsule that was observed in caracals is similar to the sonographic appearance of the spleen in domestic cats and dogs.…”

“…The presence and absence of contact between the right kidney and the right lobe of the liver that was observed in caracals also has been observed in cheetahs 4 and was attributed to the longer attachment of the kidneys similar to domestic cats. 8 The hyperechoic renal cortices compared with the medulla and good corticomedullary distinction are similar to the sonographic appearance of the kidneys in domestic cats and dogs.…”

“…12 The mean splenic thickness of 11.1 mm observed in this study was lower than the reported thickness in cheetahs (18.9 mm). 4 The difference in splenic thickness in these two species is attributed to the difference in body size.…”

Mode B ultrasonography and abdominal Doppler in crab-eating-foxes ( Cerdocyon thous )

“…Unlikely to the described in marmosets that exhibit a poor corticomedullary definition (Wagner & Kirberger 2005), in crab-eating foxes this feature is well defined and the kidney presents a corticomedullary ratio of 1:1, similarly to the reported in cheetahs (Carstens et al 2006), dogs and cats (Silva et al 2008) and coatis (Ribeiro et al 2013). In Veterinary Medicine this proportion is important for the diagnosis of kidney diseases that may present an increased cortical echogenicity with enhanced or loss of corticomedullary definition (Nyland et al 2002).…”

“…Additionally, ultrasonographic imaging proved to be effective to correlate anatomic and ultrasonographic features of abdominal organs, highlighting important characteristics considered normal for the species. Nevertheless, this method demonstrated to be a standard tool for diagnosis and clinical evaluation of crab-eating foxes, similarly to the described for ferrets (Mustela furo) (Neuwirth et al 1997), common marmoset (Callithrix jacchus) (Wagner & Kirberger 2005), cheetahs (Acinonyx jubatus) (Carstens et al 2006), tufted capuchin (Cebus apela) (Alves et al 2007) and coatis (Nasua nasua) (Ribeiro et al 2013). …”