If you have brood cows, you will occasionally experience an abortion. For every one hundred cows, three cows will abort during a given year. Most “abortions” occur during the first month or two of pregnancy, and will be recognized as a cow that “didn’t take” or “slipped her calf”. In most of these cases, abnormalities in the fetus caused the early embryonic death.
A cow will occasionally abort a fetus in a later term of her pregnancy. In these cases, it is important to remember that the best way to find out why the abortion occurred is to have a laboratory analysis of the aborted fetus performed. The fetus and placenta should be taken to the lab as soon as possible, along with a blood sample from the cow that aborted. Ideally, another blood sample is taken again in 2 weeks and sent as well. The lab results can be sent to your veterinarian, who can assist in interpreting the results. Unfortunately, even when all of the samples are sent, only 25-30% of abortion cases are diagnosed.
There are many things that can cause abortions. Infectious causes include brucellosis, leptospirosis, and BVD, just to name a few. Fortunately, many infectious causes have very effective vaccinations that are available to be given as a preventative measure. A good herd health program would include vaccinations for common infectious causes of abortion.
If you think you are having more abortions than normal, contact your veterinarian for an overall herd health and wellness check.