Ultrasonographic examination of the abdomen of the goat. I. Reticulum, rumen, omasum, abomasum and intestines.

This review article summarizes the ultrasonographic findings of the reticulum, rumen, omasum, abomasum and intestines of goats. Ultrasonographic examination is done on both sides with the goat in a standing position using a linear array or convex transducer with a frequency of 5.0 to 7.5 MHz. The shape, contour and motility of the reticulum are assessed; this organ appears as a crescent-shaped structure with a smooth contour immediately adjacent to the diaphragm. There are 0.8 to 2.1 reticular contractions per minute, which may be mono-, bi- and triphasic. The rumen is examined from the 8th to 12th intercostal spaces (ICSs) and flank on the left, and from the 12th ICS and flank on the right. The ruminal wall appears as a thick echoic line. The dorsal and ventral sacs of the rumen are differentiated based on the longitudinal groove, which forms an echoic notch. Differentiation of the dorsal gas cap, fibre mat and fluid layer is not always straightforward and varies among goats. The omasum is examined from the 6th to 11th ICSs on the right. Only the wall closest to the transducer can be imaged and it appears as a crescent-shaped echoic line medial to the liver. The omasal folds and the wall furthest from the transducer cannot be seen. In about two thirds of goats, active omasal motility is apparent as a transient reduction in size of several centimetres, followed by relaxation and return to its original size. There is an average of 1.1 contractions per minute. The abomasum is examined from the ventral midline and the left and right paramedian regions and can always be seen from the ventral midline. In all but a few goats the abomasum is also visible from the left and right paramedian areas. It appears as a heterogeneous, moderately echoic structure with echogenic stippling. The abomasal folds appear as prominent echoic bands in about two thirds of all goats. The small and large intestines are examined on the right from the 8th to the 12th ICSs. Loops of jejunum and ileum are seen mainly in cross-section and have a strong motility. The intestinal content is usually homogeneous and echoic and the diameter of the intestinal loops varies from 0.8 and 2.7 cm. The spiral colon and in many cases also the caecum can be imaged. The former is recognized by its garland-like appearance brought about by the centripetal and centrifugal coils of the intestine. In the spiral colon and the caecum, only the wall closest to the transducer can be imaged because of intraluminal gas. The wall appears as a thick echoic and slightly undulating line 5.6 to 8.0 cm in length. Ultrasonography is an imaging technique that is very well suited for the examination of the gastrointestinal tract of goats.

Ultrasonographic examination of the abdomen of the goat. II. Liver, spleen, urinary tract and greater omentum.

This review article describes the ultrasonographic findings of the liver, spleen, urinary tract and greater omentum that were previously obtained in studies of healthy female Saanen goats. Real-time B-mode ultrasonography and a linear or convex 5.0 to 7.5 MHz transducer are used to scan standing goats from both sides. The urinary bladder and urethra are also examined transrectally. The liver is scanned from the intercostal spaces (ICSs) on the right from dorsal to ventral. The parenchymal pattern consists of numerous fine echoes that are homogenously distributed across the entire organ. The dorsal visible margin of the liver runs parallel to the lung in a cranioventral to caudodorsal direction. The visible extent of the liver is largest in the 7th and 8th ICSs and the maximum thickness is measured in the 10th ICS. The caudal vena cava has a triangular shape in cross section and is seen only at the 11th or 12th ICS. The portal vein is oval to circular in cross section with stellate ramifications into the liver parenchyma. The gallbladder is pear-shaped and sometimes extends beyond the ventral margin of the liver depending on the amount of bile. In most goats, the gallbladder is only seen from the 9th or 10th ICS. The spleen is scanned from the left where it is almost always seen from the 11th and 12th ICSs. The parenchymal ultrasonographic pattern is similar to that of the liver. The splenic vessels are embedded in the parenchyma and are seen in longitudinal or cross section. The kidneys are best visualized from the flank and last two ICSs on the right. The ultrasonographic appearance varies with the sectional plane. In a sagittal plane through the hilus, the parenchyma is homogenous with fine, evenly distributed echoes. The medullary pyramids are seen near the sinus as oval to circular hypoechoic structures. The hyperechoic sinus is at the centre of the kidney. The urinary bladder is best visualized transrectally but can also be seen in many goats from either inguinal region. The content of the bladder is usually anechoic and the diameter ranges from 1.0 to 4.8 cm. The urethra is seen transrectally as two adjacent parallel echoic lines without an apparent lumen.

Ultrasonography of the abomasum in 30 Saanen goats.

This report describes the findings of ultrasonographic examination of the abomasum in 30 goats. A 5.0 MHz linear transducer was used to scan the left and right paramedian regions, the linea alba and the right abdominal wall of standing goats. The abomasum appeared as a heterogeneous, moderately echogenic structure with echogenic stippling. The abomasum could be seen from the linea alba in all the goats. The abomasal folds were easily identified in 19 goats and appeared as prominent echogenic bands. The cranial visible limit of the abomasum was -0.3 [2.34]cm from the xyphoid, and the caudal limit was 10.3 [3.08]cm caudal to the xyphoid. The visible length of the abomasum was 10.7 [1.96]cm and the maximum width 30.2 [7.43]cm. The height of the abomasum was 6.7 [1.79]cm.

Ultrasonography of the rumen in 30 Saanen goats.

This study describes the results of ultrasonographic examination of the rumen in 30 healthy Saanen goats. A linear or convex transducer with a variable frequency of 5 to 13 MHz was used to scan standing, non-sedated goats. The location and size of the rumen, the distance between the wall of the rumen and abdominal wall and the appearance and size of the gas, fibre mat and fluid layers of the ruminal contents were assessed. The rumen was seen as a large organ medial to the left abdominal wall. The wall of the rumen appeared as a thick echogenic line. The longitudinal groove was seen as an echogenic notch, which divided the rumen into the dorsal and ventral sacs. The rumen could be visualized from the 9th to 12th intercostal space (ICS) and flank on the left side in all the goats. The rumen was largest in the 12th ICS at 41.6 ± 5.13 cm and smallest in the 8th ICS at 11.3 ± 4.29 cm. The dorsal sac of the rumen was largest in the left cranial flank (17.4 ± 4.43 cm) and the ventral sac was largest in the 12th ICS on the left (29.1 ± 6.03 cm). In the cranial left flank, the rumen was situated immediately adjacent to the abdominal wall in all the goats. The spleen was located between the rumen and abdominal wall in the 8th to 12 th ICS in many of the goats. The gas, fibre mat and fluid layers of the ruminal contents could be visualized in all the goats. The gas layer was 9.9 ± 3.05 cm, the fibre mat layer 16.0 ± 4.55 cm and the fluid layer 12.2 ± 5.57 cm.