Swabbing of Mares going to Stud

There are two common types of swabs that may be required to be taken before a mare goes to stud. The majority of studs require mares to be swabbed for Contagious Equine Metritis (CEM) prior to natural covering (i.e. non-AI).  The swab can be taken at any stage of the mare's cycle and has to be assessed at a recognised laboratory.  The swab results and certificate are available in about 10 days, so plan ahead and check well in advance if the stud requires a swab.  CEM caused major problems of infertility in the equine breeding industry during the late 1970s and has largely been controlled since by the Horserace Betting Levy Board code of practice.  CEM is highly infectious and cases must be notified to DEFRA.  A small outbreak occurred last year that was traced to an imported stallion.  Strict vigilance and adherence to the HBLB code of practice is the best defence against this unpleasant and costly disease.  The organisms that cause CEM are detected on a clitoral swab.

The second swab that may be required is an endometrial (uterine) swab. This is taken to detect whether a mare has evidence of a womb infection (endometritis).  The swab has to be taken when the mare is in season and the results take about 3 days  to come through, so again plan ahead if this swab is necessary.  Endometritis is one of the most common reason for mares having difficulty getting in foal.  This swab is unnecessary in maiden mares but is advisable in mares that have had a history of being difficult to get in foal, have aborted, or had difficulty in maintaining a pregnancy in previous years.  Some studs require this as a routine in non-maiden mares.

The two swabs are often taken at the same time when the mare is in season.


The material contained in this website is presented for information purposes only . The material is in no way intended to replace professional veterinary care or attention from a professional veterinary surgeon. 

The advice given in any of our web pages cannot be used as the basis for a diagnosis or choice of treatment.

Clyde Vet Group advises that you should always consult a veterinary surgeon about any queries with animals under your care.

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