Key Technical Points for the Prevention and Treatment of Bovine Ruminal Tympany

Ruminal tympany is a disease caused mainly by the intake of large amounts of easily fermentable feed, which rapidly produces a large quantity of gas in the rumen, causing the rumen to enlarge sharply and the rumen wall to distend acutely. According to different causes, it can be divided into primary and secondary types.

1. Causes Primary ruminal tympany is mainly caused by the intake of large amounts of easily fermentable feed, such as young, succulent forage, especially leguminous forage such as Chinese milk vetch (Astragalus sinicus) and alfalfa (Medicago sativa), or silage, root and tuber feed, moldy and spoiled feed, as well as frozen feed and feed covered by rain, dew, frost or snow. In addition, poor management, such as putting the animal to work immediately after feeding or feeding and watering immediately after work, leading to indigestion of the stomach contents, can also cause this disease. Drastic climate changes can also lead to foregut dysfunction and thus cause the occurrence of this disease. Secondary foregut tympany is mostly seen in the course of diseases such as ruminal atony, traumatic reticuloperitonitis, esophageal obstruction and tetanus.

2. Clinical symptoms It often occurs rapidly after the intake of easily fermentable feed, with sharp enlargement of the left abdomen, protrusion of the paralumbar fossa, tension and elasticity on pressing the abdominal wall, and a tympanic sound on percussion. Appetite, rumination and belching quickly stop, and on auscultation the rumen motility sound disappears or a metallic sound is present. In the early stage, the affected animal is restless, looking back at the rear abdomen or kicking at the abdomen with the hind limbs; in the later stage, abdominal pain disappears, and breathing becomes difficult; in severe cases, the mouth is opened and the tongue protruded for breathing. The conjunctiva is cyanotic, the heartbeat is rapid, the pulse is weak, the small veins are engorged, and the eyeballs protrude. In the terminal stage, the animal stands unsteadily, sways when walking, sweats all over the body, and finally falls to the ground unable to stand and dies of suffocation. Chronic ruminal tympany has a slow course and mostly recurs repeatedly, with the affected animal showing symptoms of chronic indigestion.

3. Diagnosis This disease is characterized by marked distension of the abdominal circumference, protrusion of the left paralumbar fossa, elasticity on pressing, and a tympanic sound on percussion, and it is easy to confirm in combination with the medical history. For secondary ruminal tympany, diagnosis should be made according to other characteristics of the primary disease.