Ultrasonographic diagnosis of reticular diaphragmatic hernias in buffaloes

A VARIETY of ruminoreticular disorders are of interest to clinicians. Reticular diaphragmatic hernias have been reported in both buffaloes and cattle (Prasad and others 1977, 1980, Ramakumar and others 1980, Misk and others 1997, Saini and others 2000, 2001, Misk and Semieka 2001), and diagnosis is based on the clinical examination, plain and contrast reticulography and exploratory laparorumenotomy (Ramakumar and others 1980, Fubini and others 1990, Misk and Semieka 2001). Ultrasonography is useful as a diagnostic tool for reticular disorders and has been used in cases of traumatic reticuloperitonitis and reticular abscess (Braun 2003, 2005). However, its use has not been reported in the diagnosis of reticular diaphragmatic hernias in large animals. This short communication describes the successful diagnosis of reticular diaphragmatic hernias in buffaloes using ultrasonography. Twenty buffaloes with reticular diaphragmatic hernias were studied. The animals had a common history of partial anorexia with little or no defecation and recurrent tympany for two to four weeks. Eight animals were in advanced pregnancy, eight had calved recently and four were in late lactation. The lactating buffaloes showed a significant and sudden fall in milk yield. Ultrasonography was performed in the standing animal restrained in a cattle crate without any sedation, using a Concept/MCV Veterinary Ultrasound Scanner (Dynamic Imaging), in real time B-mode with a 3·5 MHz microconvex transducer. Before examination, the ventral aspect of the thoracoabdominal wall on both the right and left sides of the sternum, as well as the right lateral wall up to the level of the elbow extending from the eighth to the third intercostal space, was shaved thoroughly, washed and transmission gel was applied liberally. First, the motility of the reticulum was identified within the abdomen at the level of the sixth to seventh intercostal space by placing the transducer at the level of the elbow in the sixth and seventh intercostal spaces and then moving it downwards to the ventral midline. The reticulum was located, observed for three minutes without moving the transducer and the frequency of biphasic reticular contractions was recorded to give the reticular motility pattern (Braun 2003). Then the reticulum in the thoracic cavity was scanned. The transducer was placed at the fifth, fourth and third intercostal spaces, and, as before, scanning was performed from the elbow level down towards the ventral midline. The presence of the reticular wall and motility in the thoracic cavity indicated that the reticulum had herniated into the thoracic cavity. Ultrasonography of the reticulum was performed in all the animals using a microconvex transducer that was easy to manoeuvre in the narrow intercostal spaces of the cranial thorax. The reticulum within the abdominal cavity at the level of sixth and seventh intercostal space was crescentshaped with a smooth contour, and was more clearly discernible near the ventral midline. The serosa and mucosa of the reticulum were separated by a hypoechoic muscularis mucosa in most of the animals (Fig 1). The honeycomb structure of the reticulum could not be seen ultrasonographically in any animal. Only the reticular wall nearest the transducer and adjacent to the abdominal wall could be visualised ultrasonographically; the deeper structures could not be seen. Foreign bodies (metallic/non-metallic) within the reticulum could also not be seen. In 18 buffaloes the reticular motility in the abdomen was characterised by biphasic contractions and the reticulum was hypermotile with six to eight contractions every four minutes, while in two buffaloes no reticular motility was apparent. Scanning of the reticulum in the thoracic cavity revealed that the reticular wall was further away from the thoracic wall than it was from the abdominal wall when scanned within the abdomen. The reticular wall in the thoracic cavity appeared as a relatively straight or undulating line (Fig 2). Once the reticular wall was identified, the transducer was fixed in a position to record the reticular motility, and this was compared with the motility pattern of the reticulum in the abdominal cavity. When the motility patterns of the abdominal and herniated reticulum matched, the animal was declared positive for reticular diaphragmatic hernia. In two animals, although the reticular wall was evident in the thoracic cavity, a reticular hernia could not be determined ultrasonographically, due to the lack of a motility pattern, which was considered essential to confirm the diagnosis. No false positive results were recorded. The 20 buffaloes were subjected to exploratory laparorumenotomy to confirm the ultrasonographic findings, and all the animals were found positive for reticular diaphragmatic hernia, with a tear in the diaphragm varying in size