When Is an Abortion a Red Flag?
Dairy Pipeline: November 1997
Tom L. Bailey
Dairy Production Medicine
Virginia-Maryland Regional College of Vet Medicine
Abortions are certainly not something we like to think about or we, as producers or veterinarians, like to deal with. The first abortion that occurs may be the "window of opportunity" that stops or prevents other cows from aborting. Unfortunately, all too often we are in the midst of an abortion problem or "storm" before we recognize a real problem exists. However, this first abortion or too often any abortion is usually written-off as an unfortunate incidence, or just one of those things that happens and the aborted calf is discarded and the cow is sold. But as producers and veterinarians we need to consider the aborted fetus (calf) as a "signal or red flag" to a potential herd abortion problem. All aborted fetuses should be submitted for a diagnostic work-up. IF a diagnosis is likely to be made the fetus is the key. The fetus should be placed in a clean container and packed with ice, NOT FROZEN and submitted to a laboratory as soon as possible. Many laboratory tests necessary to determine the cause of abortion can not be run on the frozen tissues. Secondly, the cow should be immediately examined by a veterinarian, where they will likely take samples of fresh placenta, uterine fluids and the cow's blood. When a delay occurs in taking these samples, the chances of an accurate diagnosis are unlikely because of overgrowth of environmental bacteria. Producers as well must keep in mind that the abortive agent, be it a bacteria, virus, or protozoa, may have been introduced months earlier to the cow, caused an infection in the uterus and the calf, but did not cause the abortion until several months later. What does this mean in consideration of a diagnosis? When infectious agents enter the cow's body she mounts an immune response which can be measured as a blood titer. However, over time (months) this titer may decrease or be nonexistent to the point that it cannot be detected. On many occasions however, the veterinarian may take 2 blood samples, one now and one 3 weeks later to demonstrate a rise or fall in blood titers for a diagnosis. But keep in mind that the most accurate diagnosis will occur from the aborted fetus. What can we do to prevent abortions? Make sure the herd is optimally protected with a sound vaccination program, institute a production medicine program with your veterinarian, have a well managed nutrition program, practice good hygiene and sanitation protocols, isolate and test any new herd additions, examine any aborted animals (cow and fetus) for laboratory diagnosis, and consult your veterinarian when an animal aborts or dies of undetermined causes. A diagnosis of the first abortion could be the "window of opportunity" to stop other cows from aborting.