Equine Reproduction

Mayes and Scrine can provide a complete veterinary service for all breeders – whether you are an experience stud manager or breeding from your mare for the first time. Breeding from your own mare can be a very rewarding project, but remember it requires long term commitment not only in terms of time and money, but also energy and resources!

Pre-breeding examination

We recommend a pre-breeding examination including swabs and a scan (even a biopsy in problem mares) prior to breeding. Most mares come into season every 21 days and regular ultrasound scans are used to determine whether the mare is cycling and at which stage of the cycle she is in.

We are also able to inject the mare with hormone based medication to induce a season. This is sometimes more cost effective but would still require scan confirmation.

Natural Service

If you select a stud for natural covering they are likely to request certain tests before the mare goes to stud. These can vary so ask them specifically what is required, well in advance of your mare going to stud as in most cases Laboratory certificates will need to accompany h to stud.   Your mare is often more likely to conceive if sent to stud as fresh semen is the most fertile, also professional studs often have a stud vet on site every day.

Artificial Insemination (AI)

AI is becoming an increasingly popular choice by owners due to the reduced risks of injury, the distance of the stud from home, or the stallion you want may only offer AI due to a number of reasons including temperament and competition commitments. At our practice we offer chilled and frozen AI. This can be done at your yard or here at the clinic. We offer grass livery (including bringing the mare in and preparing her for stocks/insemination/scans etc) If the mare is admitted to the clinic when she comes into season she is likely to be here for around 5 days.

Pregnancy Diagnosis

Pregnancy diagnosis can be determined either by ultrasound scan, manual rectum examination or via blood tests at specific times during pregnancy. Initially your mare should be scanned at 14-15 days after insemination (or last day of covering). This is an ideal time for identification of twin pregnancies which are not viable. A second ultrasound should take place at 21 days the embryo can usually be identified at this stage. Finally a third ultrasound is recommended before day 34 where the embryos heartbeat can be seen.   Manual rectum examinations can be carried out from four to five month, but this diagnosis is unable to identify twins.   Blood samples can be taken within specific time periods once a pregnancy is established to determine a live foal.


The gestation period for mares is 340 days and most mares will foal within two weeks either side of their due date.   It can be daunting to foal a mare for the first time so please remember we are always on hand to advise or visit f necessary. Once foaled we recommend that you monitor the mare closely to ensure that she has passed the entire placenta, that the foal has suckled colostrum from its mother and also passed meconium (first faeces) all within six hours of birth. We also recommend a post partum check by a vet from both mare and foal.   Please contact the practice for further information