Ultrasonographic examination of the forestomachs and the abomasum in ruminal drinker calves

Abstract

Background: The study investigated the ultrasonographic appearance of the reticulum, rumen, omasum and abomasum of calves with ruminal drinking syndrome.

Methods: In ten milk-fed calves with ruminal drinking syndrome the reticulum, rumen, omasum and abomasum were examined by ultrasonography using a 5-MHz linear transducer before, during and after the ingestion of milk.

Results: The reticulum could be imaged in eight of ten calves before feeding. The reticular wall appeared as an echoic line, similar to mature cattle, and reticular folds were seen in eight calves. The reticular content appeared as echoic heterogeneous fluid. Reticular contractions were biphasic with 1.0 ± 0.38 contractions per minute. The rumen had a mean wall thickness of 2.1 mm dorsally, 3.5 mm at the level of the longitudinal groove, and 3.2 mm ventrally. The ventral sac of the rumen of all calves contained echoic heterogeneous liquid. During feeding the milk entering the rumen could be seen as hyperechoic liquid in five calves. The omasum was seen on the right side as a crescent-shaped line medial to the liver in seven calves. Only the omasal wall closest to the transducer was seen as an echoic line with a mean thickness of 2.7 mm. The ultrasonographic appearance of the omasum did not change during or after feeding. The abomasum was seen immediately caudal to the xyphoid on both sides of the midline before feeding. The mean length at the ventral midline was 22.2 cm. The ingesta were heterogeneous in all calves and the abomasal folds were distinct in eight. The mean lateral expansion of the abomasum from the ventral midline to the left and right varied from 8.7 to 13.8 cm and from 4.3 to 11.3 cm. The milk entering the abomasum was observed in all calves, and signs of milk clotting were seen in all calves 15 minutes after feeding.

Conclusion: This study showed that ultrasonography is useful for detecting milk in the reticulum and rumen of calves with ruminal drinking syndrome.

Figure 1

Ultrasonogram of the reticulum. Ultrasonogram of the reticulum of a 37-day-old Swiss Braunvieh calf with ruminal drinking syndrome. The 5.0-MHz linear transducer was held parallel to the sternum in the left lower thoracic area. The reticular content appears heterogeneous and echoic and the honeycomb-like structure of the mucosa can be seen. 1 Abdominal wall, 2 Spleen, 3 Reticular wall, 4 Reticular content, 5 Honeycomb-like structure of the mucosa, Cr Cranial, Cd Caudal.

Figure 2

Ultrasonogram of the ventral sac of the rumen. Ultrasonogram of the ventral sac of the rumen of a 27-day-old Swiss Braunvieh calf with ruminal drinking syndrome. The 5.0-MHz linear transducer was held parallel to the ventral midline in the left lower abdominal area. The ruminal content appears heterogeneous and echoic. The undulating line medial to the ruminal wall indicates hyperkeratosis. 1 Ventral abdominal wall, 2 Ruminal wall, 3 Ruminal content, Cr Cranial, Cd Caudal.

Figure 3

Ultrasonogram of the omasum. Ultrasonogram of the omasum and liver of a 27-day-old Swiss Braunvieh calf with ruminal drinking syndrome. The 5.0-MHz linear transducer was held on the right side parallel to the ribs in the 8th intercostal space. The omasum is seen medial to the liver as a crescent-shaped echo with the convex side toward the transducer. 1 Abdominal wall, 2 Liver, 3 Portal vein, 4 Omasum, Ds Dorsal, Vt Ventral.

Figure 4

Ultrasonogram of the abomasum. Ultrasonogram of the abomasum of a 17-day-old calf with ruminal drinking syndrome. The 5.0-MHz linear transducer was held parallel to the ventral midline in the left lower abdominal area. The abomasal content appears heterogeneous and echoic, and abomasal leaves are seen as curved structures. 1 Ventral abdominal wall, 2 Abomasal wall, 3 Abomasal leaves, 4 Ingesta, Cr Cranial, Cd Caudal.