[Abdominal ultrasound in rabbits (Oryctolagus cuniculus) - physiologic and important pathological findings]

Sonography is an important diagnostic tool in small mammal medicine, particularly in rabbits. Due to special anatomical characteristics in the rabbit, sonographic examination differs from that of dogs and cats. The selection of a suitable ultrasound transducer is essential - high-frequency linear transducers with a small contact surface are recommended. For the examination, the rabbit is positioned in dorsal recumbency on a soft surface; fixation of the hind limbs is usually not necessary.

The examination procedure is standardized, usually beginning with the urinary bladder, which is easily visualized and often contains corpuscular particles due to the rabbit's special calcium metabolism. A common condition is urolithiasis. This may result in both bladder sludge and calculi throughout the urinary tract, possibly leading to obstructions.

The female genital tract, including its cervix duplex and uterus duplex, is examined systematically. Important pathologies include endometrial hyperplasia and uterine adenocarcinoma, which are characterized by changes in the uterine wall and fluid accumulation in the organ´s lumen. Sonography plays an important role in early detection of these pathologies.

The adrenal glands and spleen may also be visualized sonographically. The latter is tongue-shaped and moderately echogenic. The pancreas is considered to be difficult to visualize but may be seen in certain areas. The liver is assessed sonographically as well; the caudate lobe is easily accessible. In cases of liver lobe torsion, sonography reveals changes in echogenicity and perfusion, often accompanied by free fluid and surrounding tissue reaction.

The gastrointestinal tract is not always fully visible and accessible due to gas and food content, but certain sections such as the stomach, duodenum, sacculus rotundus, and appendix can usually be clearly visualized. Sonographic features such as wall thickness and layering are used to assess these organs. An important disease of the gastrointestinal tract is appendicitis/sacculitis, which is characterized by a thickened wall and a fluid filled lumen.