As we discussed in an earlier issue of Vet’s Corner (September 2001), abortion in ewes has many causes including infectious, toxic, genetic, nutritional, and environmental.  In many cases, the actual cause may have occurred days, weeks, months, or even a year earlier and are now gone, making a positive diagnosis difficult.  A decomposed or contaminated fetus only further complicates the diagnostic efforts. Due to these factors, up to 50% of all ovine abortions may go undiagnosed.  Despite the odds, at least a presumptive diagnosis is necessary to take corrective action or develop a preventative plan in hopes of reducing or eliminating further losses.

 So what should you do if your ewes begin to abort?

  1. Call your veterinarian as soon as possible.  They can advise you on how to handle the material before they arrive to collect samples.

  2. Isolate the aborting ewe and aborted fetus from the rest of the flock.  These materials may be infectious and can be transmitted to the other ewes.

  3. Avoid extensive foot traffic between the affected and unaffected areas.  Wear separate coveralls and boots if possible.  Disinfect thoroughly between visits.

  4. Care must be taken while handling the materials because some of the infectious agents are also contagious to man.

  5. If your veterinarian is not readily available or the risk of predation is high, it may advisable to place the fetus and placenta in a clean plastic bag.  The samples should be chilled, but not frozen. Transportation to a diagnostic laboratory or your veterinarian should be performed as soon as possible.

  6. After the samples are collected, dispose of any remaining material completely and properly. Disinfect the surrounding area very well.  Your veterinarian can help advise you on disinfectant selection.

  7. Based on your veterinarian’s presumptive diagnosis, a plan of action should be developed and followed to reduce any further losses.

At Colorado Serum Company, we provide vaccines specifically developed to prevent two of the most common causes of ovine abortion, enzootic abortion (EAE) and vibriosis/campylobacteriosis.  If these diseases are confirmed or suspected, a preventative plan should include vaccination with one of the following.


  • For the prevention of enzootic abortion of ewes (EAE) caused by Chlamydia psittaci.

  • Vaccinate ewes sixty days prior to breeding with a booster dose thirty days later.  Revaccinate yearly prior to breeding.


  • For the prevention of vibrionic abortion of ewes (vibriosis/campylobacteriosis) caused byCampylobactre fetus subspecies jejuni (type I) and subspecies intestinalis (type V).

  • Vaccinate ewes thirty days prior to breeding with a booster dose sixty to ninety days later. Revaccinate yearly around breeding time.

As always, read and follow label instructions.

For help with your flock health program, feel free to give our veterinary staff a call.