Evaluation of injections of collagenase and oxytetracycline via the umbilical artery as treatment for retained placenta in cattle.

OBJECTIVES

To test whether oxytetracycline inactivates collagenase when combined as a potential treatment for retained fetal membranes in cattle and to determine whether oxytetracycline passes to blood from fetal membranes after intraplacental injection.

DESIGN

Prospective, controlled study.

SAMPLE POPULATION

288 placentomes from 12 cows in their third trimester of pregnancy and 4 cows at term pregnancy.

PROCEDURE

8 experimental groups were established: saline control, collagenase, collagenase plus oxytetracycline at 3 dosages, and oxytetracycline at 3 dosages. Placentomes were infused through an umbilical vessel with the test solutions and incubated at 39 C for 4 hours. Immediately after incubation, the force needed to detach cotyledons from caruncles was measured by a manometric technique. Cotyledon-caruncle interface fluids were analyzed for hydroxyproline (collagen breakdown) and total protein contents. A combination of collagenase and oxytetracycline was injected via umbilical arteries of cows undergoing cesarean section and in cows with retained fetal membranes after natural delivery. Antibiotic residue in blood was determined by the Bacillus stearothermophilus disk assay.

RESULTS

There were no significant differences among collagenase and collagenase plus oxytetracycline groups in the amount of pressure needed to separate cotyledon from caruncle, amount of hydroxyproline released, and amount of total protein broken down. The 4 cows tested negative for oxytetracycline in the blood.

CLINICAL RELEVANCE

Oxytetracycline and collagenase may be a potential combination treatment for retained fetal membranes in cattle. In addition, the lack of antibiotic residue detection in blood may be of regulatory relevance.