Content uploaded by Mohamed Tharwat
Author content
All content in this area was uploaded by Mohamed Tharwat on Apr 27, 2014
Content may be subject to copyright.
CVJ / VOL 53 / DECEMB ER 2012 1273
Article
Ultrasonography of the liver and kidneys of healthy camels
(Camelus dromedarius)
Mohamed Tharwat, Fahd Al-Sobayil, Ahmed Ali, Sébastien Buczinski
Abstract — This study describes the ultrasonography of the liver and kidneys of healthy camels (Camelus
dromedarius). Images of the liver were obtained from the 11th to 5th intercostal spaces (ICSs). The distance between
the dorsal liver margin and the midline of the back was shortest (39.1 6 7.4 cm) at the 11th ICS and increased
cranially to 5th ICS. The size of the liver was largest at the 9th ICS and smallest at the 5th ICS. In 6 camels the
right kidney was visualized from the 10th and 11th ICSs and upper right flank and in the 10th and 11th ICSs in
the remaining 16 camels. In all camels, the left kidney was imaged from the caudal left flank. In 21 camels, the
differentiation between the renal cortex and medulla was clearly visible in the ultrasonograms. Ultrasonographic
description of the liver and kidneys provides a basic reference for diagnosing hepatic and renal disorders in
camels.
Résumé — Échographie du foie et des reins de chameaux en santé (Camelus dromedarius). Cette étude décrit
l’échographie du foie et des reins de chameaux en santé (Camelus dromedarius). Des images du foie ont été obtenues
du 11e au 5e espace intercostal (EIC). La distance entre le bord marginal du foie dorsal et la ligne médiane du dos
était la plus courte (39,1 6 7,4 cm) à la 11e EIC et a augmenté cranialement jusqu’au 5e EIC. La taille du foie
était la plus importante au 9e EIC et la plus petite au 5e. Chez 6 chameaux, le rein droit a été visualisé du 10e et
du 11e EIC et du flanc droit supérieur et aux 10e et 11e EIC chez les 16 chameaux restants. Chez tous les chameaux,
le rein gauche a été imagé à partir du flanc gauche caudal. Chez 21 chevaux, la différentiation entre le cortex rénal
et la médulla était clairement visibles dans les échogrammes. La description échographique du foie et des reins
fournit une référence de base pour le diagnostic des troubles hépatiques et rénaux chez les chameaux.
(Traduit par Isabelle Vallières)
Can Vet J 2012;53:1273–1278
Introduction
Although dromedary camels (Camelus dromedarius) are a
common domestic species in Africa and Asia, they are
also found in the northern hemisphere. Hepatic and renal dis-
eases are relatively common (1,2), and many of these diseases
are not diagnosed because the signs are vague or nonspecific.
Hematology and serum biochemistry may be unhelpful (3),
and ancillary tests may be required (2,3). An ultrasonographic
examination of the liver and kidneys can give detailed informa-
tion on the size, position, and parenchymal pattern of the liver
and kidneys (4,5).
Ultrasonography is a useful tool for the diagnosis of many
liver and renal diseases in cattle (4,5). In cows, liver tumors (6),
thrombi in the caudal vena cava (CVC) (7), focal and diffuse
fatty liver (4,8), and hepatic abscesses (4) are best imaged by
ultrasonography. Ultrasonography has also been used to diagnose
embolic nephritis (9), pyelonephritis (5,10), and renal cysts and
urolithiasis in cattle (11). Thus, ultrasonography might be a
valuable aid for the diagnosis of liver and kidney diseases in the
dromedary camel. However, since no specific study has described
normal ultrasonographic findings, it is important to i) ultrasono-
graphically characterize the localization, visible boundaries, and
appearance of the liver, CVC, and portal vein (PV) in healthy
camels; and ii) determine the best positions for imaging right
Department of Veterinary Medicine, College of Agriculture and
Veterinary Medicine, Qassim University, Saudi Arabia (Tharwat,
Al-Sobayil, Ali); Clinique ambulatoire bovine, Département des
Sciences Cliniques, Faculté de Médecine Vétérinaire, Université
de Montréal, Saint-Hyacinthe, Quebéc, Canada (Buczinski).
Address all correspondence to Dr. Sébastien Buczinski; e-mail:
s.buczinski@umontreal.ca
Dr. Tharwat’s current address is Department of Animal
Medicine, Faculty of Veterinary Medicine, Zagazig University,
Egypt.
Use of this article is limited to a single copy for personal study.
Anyone interested in obtaining reprints should contact the
CVMA office (hbroughton@cvma-acmv.org) for additional
copies or permission to use this material elsewhere.
12 74 CVJ / VOL 53 / DECE MBE R 2012
ARTICLE
and left kidneys, and characterize which of the renal structures
can be visualized ultrasonographically.
Materials and methods
Animals, history, and physical examination
Details of this study design have been reported recently
(12). Briefly, 22 camels (Camelus dromedarius) (mean age:
8.8 6 3.8 y), determined to be free of hepatic and renal diseases
on the basis of thorough physical and laboratory examinations,
were examined at the Veterinary Teaching Hospital, Qassim
University, Saudi Arabia. Two of the camels were males and 20
were females, 5 of which were 2 to 3 months pregnant. The
camels were selected on the basis of absence of any disease. The
camels were then examined (13), paying special attention to
their liver and kidneys. The camels were excluded if they had any
clinical signs of illness such as fever, inappetance, or anorexia.
The results of liver and kidney function tests on ethylenedi-
amine tetra-acetic acid (EDTA) blood samples collected from
the jugular vein were within the reference ranges for camels. All
camels had free access to feed and water. The body condition
score (BCS) of each camel was assessed (14) based on a scale of
1 (very thin) to 5 (fat); the average was 3.4 6 0.3. All camels
were maintained under the Laboratory Animal Control Guidelines
of Qassim University, which conform to the Guide for the Care
and Use of Laboratory Animals of the National Institutes of Health
in the USA (NIH publication No. 86-23, revised 1996).
Ultrasonographic examination
The foreleg of each camel was flexed and tied at the carpal
joint. The head was then held and the animal pushed to sternal
recumbency. The fore and hind legs were then tied near the
carpal and hock joints, respectively. Both sides of the thorax
and abdomen were clipped and the skin shaved. The animals
were lightly sedated using intravenous xylazine (10% Bomazine;
Bomac Laboratories, Manukau City Auckland, New Zealand),
0.02 mg/kg body weight (BW). Ultrasonographic examination
was carried out using 3.5 MHz sector and 7.5 MHz linear trans-
ducers (SSD-500; Aloka, Tokyo, Japan). Machine gain settings
were fixed throughout the experiment. After the application of
transmission gel to the transducer, the liver was examined begin-
ning at the right paralumbar fossa and extending forward to the
5th intercostal space (ICS). Each ICS was examined dorsally to
ventrally with the transducer held parallel to the ribs. Initially,
the hepatic texture, hepatic and PVs, and visceral and diaphrag-
matic surfaces were examined. The position of the dorsal and
ventral liver margins, the CVC and the PV were measured in
relation to the dorsal midline. Measurements of distance from
the dorsal midline were taken afterwards using ultrasound to
identify the pertinent inner points (15).
The right and left kidneys were examined at the upper right
and caudal left paralumbar fossa. The transducer was directed
perpendicularly when examining the right kidney and caudally
when examining the left kidney. The right and left kidneys were
also examined in the 11th ICS and middle left paralumbar fossa
through the so-called hepatic and splenic windows, respectively.
The distances between the body surface and kidneys, the verti-
cal and horizontal diameters and the diameter of the cortex,
medulla, and sinuses were determined. The left kidney was
also imaged longitudinally and in a cross-sectional view, and
transrectally with the 7.5 MHz linear transducer. Transmission
gel was applied to the transducer which was then placed in a
plastic rectal glove before being introduced into the rectum.
The transducer was placed ventrally, laterally, and dorsally to
the left kidney. At the end of the examination, all camels were
slaughtered and thoroughly examined.
Statistical analysis
The data are presented as means 6 standard deviation (SD) and
the analysis was conducted using a computer program (SPSS
Version 16.0, 2007; SPSS, Chicago, Illinois, USA). Differences
between the dimensions of the right and left kidneys were ana-
lyzed using Student’s t-test. The level of significance was set at
P , 0.05.
Results
Ultrasonography of the liver
Images of the liver were obtained in the camels via the 11th to
6th ICSs. Additionally, in 4 camels, the hepatic parenchyma was
visible at the 5th ICS. The parenchymal pattern of the normal
liver consisted of numerous medium echoes uniformly distrib-
uted over the entire liver (Figure 1). The portal and hepatic veins
could be seen within the normal texture. The lumens of these
vessels were anechoic. The PVs could be positively differentiated
from the hepatic veins in the area of the portal fissure because
the PVs in this region were characterized by stellate ramifications
(Figure 1). The bile ducts could not be identified and imaged
in any of the camels.
Table 1 shows the distances between the dorsal midline and
the proximal and distal liver margins from the 11th to 5th ICSs.
Figure 1. Ultrasonogram of the portal vein in a healthy camel.
The portal vein could be positively differentiated from the hepatic
vein in the area of the portal fissure because the portal vein
in this region was characterized by stellate ramifications. The
image was taken at the right 10th intercostal space. 1 — hepatic
parenchyma; 2 — portal vein; 3 — lung shadow; 4 — caudal
glandular sacs; DS — dorsal; VT — ventral.
CVJ / VOL 53 / DECEMB ER 2012 1275
ARTICLE
The proximal margin of the liver was positioned in parallel to
the border of the lungs in a cranioventral to caudodorsal direc-
tion. The distance between the proximal liver margin and the
dorsal midline was shortest (39.1 6 7.4 cm) at the 11th ICS
and increased cranially to the 5th ICS. Similarly, the distance
between the ventral liver margin and the dorsal midline was
shortest (50 6 6.8 cm) at the 11th ICS and increased cranially
to the 5th ICS. The size of the liver was largest at the 9th ICS
and smallest at the 5th ICS. The depth of the CVC and PV
from the body surface and hepatic capsule and the diameters of
these vessels at the different ICSs are summarized in Table 1.
The CVC was consistently situated dorsally and medially to
the PV. The CVC was imaged as a triangle (Figure 2). In all
camels, the CVC was visible at the 11th and 10th ICSs and its
distance from the hepatic capsule to the body surface was simi-
lar at both locations. The diameter of the CVC was largest at
the 10th ICS (3.8 6 0.4 cm). The PV was imaged at the 11th,
10th and 9th ICSs and was round on cross-sectional view. Its
distance from the hepatic capsule was largest at the 11th ICS
and smallest at the 10th ICS. The size of the PV was largest at
the 9th ICS and was smaller, but similar, at the 11th and 10th
ICSs. Compared to the echogenic wall of the PV, the hepatic
vein wall appeared to be hypoechoic to anechoic (Figure 3).
Ultrasonography of the kidneys
Both kidneys were successfully imaged in all camels. The right
kidney was visualized at the 10th and 11th ICSs and the upper
right flank in 6 camels. In the other 16 animals, it was visible at
the 10th and 11th ICSs. The left kidney was imaged from the
caudal left flank in all camels. In 21 camels, the differentiation
Table 1. Dimensions (means 6 SD) of the liver parenchyma, caudal vena cava, and portal vein obtained at the 5th through 11th right
intercostal spaces in 22 healthy camels as estimated by ultrasound examination
Intercostal space
11th 10th 9th 8th 7th 6th 5th
Liver
Distance (cm) from proximal margin 39.1 6 7.4 44.9 6 8.2 50.8 6 7.5 56 6 6.3 61.1 6 4.4 64.9 6 6.4 67 6 2.0
to midline
Distance (cm) from ventral margin 50.0 6 6.8 59.9 6 8.0 68.9 6 6.9 73.7 6 6.2 75.1 6 4.3 75.4 6 5.1 76.5 6 3.5
to midline
Thickness (cm) 13.6 6 4.0 14.1 6 4.3 16.5 6 6.3 12.9 6 4.6 13.2 6 3.3 10.2 6 3.7 9.5 6 3.5
Caudal vena cava
Distance (cm) from hepatic capsule 9.9 6 1.9 9.9 6 2.5
Distance (cm) from body surface 11.6 6 1.6 12.9 6 2.3
Diameter (cm) 3.1 6 0.5 3.8 6 0.4
Portal vein
Distance (cm) from hepatic capsule 9.3 6 1.7 7.8 6 2.2 8.2 6 2.4
Distance (cm) from body surface 9.9 6 2.6 9.2 6 2.5 10.0 6 1.6
Diameter (cm) 3.3 6 0.5 3.3 6 0.6 3.8 6 0.9
Figure 2. Ultrasonogram of the caudal vena cava in a healthy
camel. In this animal, the imaged vein was triangular. The image
was taken at the right 11th intercostal space. 1 — hepatic
parenchyma; 2 — lung shadow; 3 — caudal vena cava;
DS — dorsal; VT — ventral.
Figure 3. Ultrasonogram of the hepatic vein in a healthy camel.
The vein wall appeared to be anechoic. The image was taken
at the right 9th intercostal space. 1 — hepatic parenchyma;
2 — lung shadow; 3 — hepatic vein; DS — dorsal; VT — ventral.
1276 CVJ / VOL 53 / DECEMBER 2012
ARTICLE
between the renal cortex and medulla was clearly visible in
the ultrasonograms. This differentiation was not possible in
1 animal. The echogenicity of various renal structures varied.
The renal cortex was relatively hyperechoic compared with the
renal medulla in all camels. In both kidneys, the hyperechogenic
renal sinus was more differentiated than the cortex and medulla.
The right and left renal parenchyma were less echogenic than
the neighboring hepatic and splenic parenchyma. The medul-
lary pyramids had a conic triangular appearance and were less
echogenic than the remaining parenchyma. The renal hilus could
be imaged when the transducer was placed in the paralumbar
fossa and rotated about its longitudinal axis (Figure 4). However,
the renal artery and vein and the ureter could not be accurately
identified, probably due to the lack of Doppler effect in the
device we used. Ultrasonography via the hepatic (Figure 5) and
splenic (Figure 6) windows also resulted in good images of the
right and left kidneys, respectively. When examined transrectally,
the left kidney was accessible in all camels. In 18 animals, the
entire left kidney was evaluated and the cranial pole could be
reached (Figure 7). However, in the other 4 camels the entire
kidney could not be reached and imaged. The left kidney
could also be easily imaged transrectally in all camels in a cross-
sectional view (Figure 8).
Figure 4. Ultrasonogram of a longitudinal section of the
right kidney in a healthy camel. The image was taken from the
upper right flank. RH — renal hilus; DS — dorsal; VT — ventral;
C — cortex; M — medulla; RS — renal sinus.
Figure 5. Ultrasonogram of a longitudinal section of the right
kidney in a healthy camel. The image was taken at the right
10th intercostal space though the hepatic window. DS — dorsal;
VT — ventral.
Figure 6. Ultrasonogram of a longitudinal section of the left
kidney in a healthy camel. The image was taken from the middle
left flank though the splenic window. DS — dorsal; VT — ventral.
Figure 7. Transrectal ultrasonogram of the cranial pole of the left
kidney in a healthy camel. C — cortex; M — medulla; RS — renal
sinus; RW — rumen wall.
CVJ / VOL 53 / DECEMB ER 2012 1277
ARTICLE
Table 2 shows the measurements of the right and left kid-
neys, including the distance to the body surface, the thickness
of the cortex, medulla, and renal sinus, and the vertical and
horizontal diameters of both kidneys. The distance between the
body surface and the left kidney was greater than that for the
right kidney. There were no statistically significant differences
between the thicknesses of the cortex, medulla or renal sinus
in both kidneys. The vertical diameter of both kidneys was sig-
nificantly smaller than the horizontal diameter. The horizontal
diameter of the left kidney was smaller than that of the right
kidney; however, the vertical diameter was not significantly
different between both kidneys.
Discussion
Ultrasonography has not been employed as an aid to the diag-
nosis of hepatic and renal pathology in camels. In many cases,
the diagnosis of such conditions cannot be made before either
an exploratory laparotomy or necropsy is performed. Diagnostic
ultrasonography enables the clinician to non-invasively obtain
an accurate assessment of the liver and renal parenchymas. In
cattle, sheep and goats, hepatic and renal ultrasonography is a
well-established procedure (15,16–19).
From the findings of this study, the liver can be effectively
visualized in at least 6 successive ICSs, extending 10 to 17 cm
within each ICS. In cattle, the liver is best viewed more caudally
at the 10th through to the 12th ICS (15); in sheep, more cau-
dally at the 9th through to the 10th ICS (17); and in goats more
cranially at the 7th through to the 9th ICS (19). In this study,
the liver was seen at the 5th ICS in only 4 out of the 22 camels.
The horizontal topographic anatomy of the liver in camels might
explain why it was possible to visualize the hepatic parenchyma
in at least 6 successive ICSs, which is more than in cattle, sheep,
and goats. In cattle, sheep, and goats, the parenchymal pattern
of the normal liver consists of numerous weak echoes uniformly
distributed over the organ (15,17,19). In the present study,
the parenchymal pattern of a normal camel’s liver consisted of
numerous medium echoes uniformly distributed over the entire
liver. This difference may be due to the camel’s liver containing
higher amounts of interlobular connective tissue, leading to a
firmer consistency than seen in other domesticated animals (20).
As shown in other ruminant studies (15,17,19), the CVC
appeared to be triangular. Generally, congestion of the systemic
circulatory system results in dilatation of the CVC (4). Causes
include right-sided heart failure, thrombosis of the CVC, and
compression of the CVC in the thorax or sub-phrenic region by
space-occupying lesions (7). The ultrasonographic appearance
of the CVC is a substantial aid in diagnosing congestion of the
systemic circulation. In cases with congestion of the CVC, a
change in the cross-sectional shape of the vein is important for
making a reliable diagnosis. In cows, the CVC loses its normal
triangular shape when occluded by a thrombus and becomes
round to oval on ultrasonograms (4). At the same time, the
diameter of the vein increases. In cattle, hepatic veins and even
jugular veins are always dilated and the CVC is oval when there
is congestion of the systemic circulation (4).
In this study, the PV, which transports nutrient-rich blood
from the intestine to the liver, was circular on cross-sectional view
and had stellate ramifications into the liver parenchyma, similar
to previous findings in cattle, sheep, and goats (15,17,19). In
contrast to the CVC, the PV was seen at the 9th to 11th ICSs.
Similar to findings in other ruminants, the wall of the intrahe-
patic PV was more echoic than that of the hepatic vein. The
echogenic wall of the PV was attributed to the connective tissue
that surrounds the vein, whereas little or no connective tissue
surrounds the hepatic veins (15). The PV is characterized by a
star-shaped ramification and can be easily differentiated from the
hepatic vein. This star shape might be attributed to the division
of the PV into right and left branches, upon entering the porta
hepatis (15).
Manifestations of diseases of the urinary system in camels
may be subtle (3), and renal diseases are often misdiagnosed
as a cause of illness. Most veterinary practitioners use the gross
appearance of urine, an evaluation of abnormal urine constitu-
ents based on multiple reagent test strips, and signs found upon
physical examination as indicators of urinary tract disease (5).
Vague illnesses that originate in the urinary system may require
Table 2. Dimensions (means 6 SD) of the right and left kidneys
imaged by ultrasound, from the upper right and caudal left
paralumbar fossa in 22 healthy camels
Right kidney Left kidney P-value
Distance (cm) from body surface 1.8 6 0.5a 2.5 6 0.6b 0.03
Cortex (cm) 1.7 6 0.6a 1.7 6 0.3a 0.6
Medulla (cm) 2.7 6 0.6a 3.0 6 1.0a 0.2
Renal sinus (cm) 3.0 6 0.7a 3.6 6 0.9a 0.1
Vertical diameter (cm) 8.4 6 1.4a 9.8 6 1.9a 0.06
Horizontal diameter (cm) 18.1 6 2.6a 14.5 6 3.0b 0.005
Values with different letters in the same row differ significantly.
Figure 8. Transrectal ultrasonogram of a cross-sectional view
of the left kidney in a healthy camel. C — cortex; M — medulla;
RS — renal sinus; RC — renal capsule.
1278 CVJ / VOL 53 / DECEMBER 2012
ARTICLE
more ancillary data in the form of complete urinalysis, serum
electrolytes and chemistry, and complete blood counts for a
diagnosis (9). In cattle, ultrasonography is a useful aid in the
diagnosis of renal diseases (5,10), and is also used to obtain renal
tissue specimens (21).
In this study, the right kidney was best imaged ultraso-
nographically from the 10th and 11th ICSs and the upper
right flank. In addition, ultrasonography via the liver window
provided good images of the right kidney. The best images for
determining the vertical and horizontal diameters of the right
kidney and its cortex, medulla, and sinus were achieved when
the transducer was placed on the upper right flank. The right
kidney was always imaged longitudinally from this position. The
renal hilus could always be visualized from the right paralumbar
fossa, with the transducer rotated about its longitudinal axis.
The results of this study indicate that the left kidney can
also be easily examined and imaged either transcutaneously
from the caudal left flank or transrectally. The splenic window
also provided good ultrasonographic images of the left kidney
in the camels. In cattle, examination of the left kidney is always
performed transrectally by using a special transducer (18). The
splenic window cannot be used in most cows due to interference
by gas contained by the ruminal dorsal wall. In this study, the
left kidney was accessible transcutaneously from the caudal left
paralumbar fossa by the same technique as used for the right
kidney. The cortex and medulla cannot be ultrasonographically
differentiated in cattle (16); but, in the present study, they could
easily be differentiated in most of the camels.
In conclusion, the ultrasonographic description of the hepatic
and renal parenchyma in this study provides the basic refer-
ences for diagnosing hepatic and renal disorders in dromedary
camels. The procedure is a useful aid in clinical examination
and is an important tool for the diagnosis of such conditions.
This imaging modality is a unique method for the non-invasive,
patient-side evaluation of the hepatic and renal parenchyma and
their blood vessels, and the renal cortex, medulla, and sinus. The
diagnosis of hepatic and renal diseases in camels is difficult, and
may be overlooked on many occasions; thus, ultrasonography
provides a means of detecting hepatic and renal pathology more
reliably in dromedary camels.
Acknowledgments
This study was supported by the Deanship for Scientific
Research (SR-D-011-602), Qassim University, Saudi
Arabia. English was revised at proof-reading-service.com
(http://www.proof-reading-service.com). CVJ
References
1. Al-Ani F.K. The Urinary System. In: Al-Ani FK, ed. Camel Management
and Diseases. Jordan, Al-Sharq printing press, 2004:263–267.
2. Bakhsh A. The liver. In: Al-Ani FK, ed., Camel Management and
Diseases. Jordan: Al-Sharq printing press, 2004:213–217.
3. Fowler ME. Digestive system. In: Medicine and Surgery of Camelids.
3rd ed. Ames, Iowa: Blackwell Publishing, 2010:351–402.
4. Braun U. Ultrasonography of the gastrointestinal tract in cattle. Vet
Clin North Am Food Anim Pract 2009;25:567–590.
5. Floeck M. Ultrasonography of bovine urinary tract disorders. Vet Clin
North Am Food Anim Pract 2009;25:651–667.
6. Braun U, Nuss K, Soldati G, Ossent P. Clinical and ultrasonographic
findings in four cows with liver tumours. Vet Rec 2005;157:482–484.
7. Mohamed T, Sato H, Kurosawa T, Oikawa S. Ultrasonographic localisa-
tion of thrombi in the caudal vena cava and hepatic veins in a heifer. Vet
J 2004;168:103–106.
8. Mohamed T, Oikawa S, Kurosawa T, et al. Focal fatty liver in a heifer:
Utility of ultrasonography in diagnosis. J Vet Med Sci 2004;66:
341–344.
9. Divers TJ. Urinary tract diseases. In: Divers TJ, Peek SF, eds. Rebhun’s
Diseases of Dairy Cattle. 2nd ed. Philadelphia, Pennsylvania:
WB Saunders, 2007:447–466.
10. Floeck M. Sonographic application in the diagnosis of pyelonephritis
in cattle. Vet Radiol Ultrasound 2007;48:74–77.
11. Braun U, Nuss K, Sydler T, Lischer C. Ultrasonographic findings in
three cows with ureteral obstruction due to urolithiasis. Vet Rec 2006;
159:750–752.
12. Tharwat M, Al-Sobayil F, Ali A, Buczinski S. Transabdominal ultraso-
nographic appearance of the gastrointestinal viscera of healthy camels
(Camelus dromedarius). Res Vet Sci 2012;93:1015–1020.
13. Köhler-Rollefson I, Mundy P, Mathias E. Managing and treating cam-
els. In: A Field Manual of Camel Diseases: Traditional and Modern
Healthcare for the Dromedary. London, England: ITDG publishing,
2001:1–67.
14. Sghiri A, Driancourt MA. Seasonal effects on fertility and ovarian fol-
licular growth and maturation in camels (Camelus dromedarius). Anim
Reprod Sci 1999;55:223–237.
15. Braun U. Ultrasonographic examination of the liver in cows. Am J Vet
Res 1990;51:1522–1526.
16. Braun U. Ultrasonographic examination of the right kidney in cows.
Am J Vet Res 1991;52:1933–1939.
17. Braun U, Hausammann K. Ultrasonographic examination of the liver
in sheep. Am J Vet Res 1992;53:198–202.
18. Braun U. Ultrasonographic examination of the left kidney, the urinary
bladder, and the urethra in cows. J Vet Med A 1993;40:1–9.
19. Braun U, Steininger K. Ultrasonographic characterization of the liver,
caudal vena cava, portal vein, and gallbladder in goats. Am J Vet Res
2011;72:219–225.
20. Lalla S, Drommer W. Observations on the fine structure of the liver
in the camel (Camelus dromedarius). Anat Histol Embryol 1997;26:
271–275.
21. Mohamed T, Oikawa S. Efficacy and safety of ultrasound-guided per-
cutaneous biopsy of the right kidney in cattle. J Vet Med Sci 2008;70:
175–179.
