Two-Stage Rumen Cannulation Technique in Dairy Cows

ObjectiveTo describe a 2-stage rumen cannulation technique for dairy cows. Study DesignCase series. Animals172 dairy cows from 2 research institutions. MethodsThe 2-stage rumen cannulation technique first exteriorized a rumen segment within a wooden clamp, fixing the clamp to the skin with 6 mattress sutures. After 1 week, the necrotic rumen segment was removed, leaving a rumen fistula in which a 7.5cm cannula was inserted. This was replaced by a 10cm cannula a further 1 week later. The surgery took an average of 30minutes. At least 1 assistant is required for the technique. ResultsThe overall complication frequency was 7/172 (4%). One cow and 1 heifer aborted less than 10 days after surgery. Two late-pregnant heifers died from peritonitis after insertion of the 7.5cm cannula because of incomplete adhesion of the rumen to the abdominal wall. The exteriorized rumen segment slipped back in the abdomen in 3 cows but was successfully re-clamped prior to insertion of the 7.5cm cannula. ConclusionA high success rate was achieved with this 2-stage cannulation technique. Postoperative complications were attributed to delayed adhesion of the rumen, perhaps because of stress-related factors (e.g., transport, mixing with other animals, transition period).