ULTRASOUND

The use of ultrasound intensifies the reproduction process in the mare.   By pinpointing ovulation at breeding and then diagnosing early pregnancies, establishing pregnancy in the mare receives the attention it deserves. 

The more common use of ultrasound is diagnosing early pregnancies.  Pregnancies as early as fourteen days after ovulation can be seen on the ultrasound screen.   One of the many advantages of this early diagnosis is to determine if pregnancy exists before the mare is due back in heat.   The mare usually cycles on a twenty one day schedule.   By determining she is pregnant, the mare does not have to be taken to the stallion for teasing.  If the mare is found to be open, there is still time to take cultures and cytology specimens and to breed her. 

The ultrasound machine has important uses in the breeding process.   It allows us to visualize the ovaries and watch the developing follicles.  We know that follicles are reaching maturity when they reach a certain size (this size varies with the size of the breed) and shape.  This prevents us from breeding too early, as the mare may be showing signs of heat and still be days away from ovulation. 

To prevent over confidence when predicting ovulation, we know the mare can develop follicles without coming into heat.  If we watch follicle development alone, we may prepare for breeding without the mare being in heat.  To confirm that the mare is in heat, we also look at the lining of the uterus.  It will become progressively edematous (swollen) until just before ovulation (releasing the egg from the follicle on the ovary).  It is only when we see both an enlarged follicle and edema within the uterus that we are comfortable scheduling breeding.  

If the mare is being hauled some distance to the stallion for a onetime cover, or if semen is being shipped in to breed the mare, timing is very important.  The ultrasound allows us to make the above evaluation in preparation for recommending the time for optimal breeding.  With the increasing use of frozen semen, insemination immediately before and after ovulation is critical to its successful use.

We hope this brief description of the ultrasound helps explain the importance of its use in your mare.