Category Archives: pregnancy

Oxytocin Use to Support Pregnancy?

Posted: | September 9, 2023

Oxytocin Use to Support Pregnancy Instead of Regumate (Altrenogest)? It seems initially counter-intuitive to consider oxytocin use to support pregnancy instead of Regumate or other altrenogest treatments which are commonly used to potentially increase – or at least maintain – progestin levels during early pregnancy in the mare. Oxytocin causes uterine contractions and will expel the pregnancy, right?… Read More »

Words To Lose!

Posted: | April 15, 2023

When lecturing on equine reproduction our lead lecturer Jos Mottershead often comments that there are several words to lose in order to avoid confusion and – plainly – being incorrect. The words he always cites are “never” and “always”, because the moment that one uses those words, invariably someone in the audience comes up with a situation which… Read More »

Ventral Rupture in the Pregnant Mare

Posted: | February 3, 2021

Late Term Pregnancy Problems in the Mare – Ventral Rupture in the Mare – A late-term mare presents with ventral oedema and obvious discomfort. What is the diagnosis and treatment? By Jonathan F Pycock, BVetMed, PhD, DESM, MRCVS, RCVS Specialist in Equine Reproduction First Published in UK VET 8;3, April 2003 The 19-year-old multiparous pregnant Percheron mare illustrated… Read More »

Double Trouble – The Twin Dilemma

Posted: | February 3, 2021

Managing Twinning in the Mare – While most equine pregnancies are simple, twinning when it happens is an issue. Here we discuss managing twinning in the mare. By Jos Mottershead and Kathy St. Martin You’ve read all the articles at, your mare was in heat, you jumped through all the various hoops you needed to in order… Read More »

When is an Embryo not an Embryo?

Posted: | February 2, 2021

Equine Pregnancy Terminology – Conceptus? Embryo? Fetus? Abortion? Stillbirth? Premature? So many terms – a little light offered here in so much confusion! By Dr. Neil Williams, Livestock Disease Diagnostic Center, University of Kentucky, Lexington, Kentucky. There are different terms to describe the developing foal in utero. Furthermore, certain terms are used to describe the foal when it… Read More »

Individual Tuition

Posted: | December 17, 2020

One-on-One Tuition While we are renowned for offering short courses on the subject of horse breeding worldwide, we not infrequently encounter people either at the courses or through our website who are in need of more specific one-on-one tuition. Perhaps they do not own stallions but want to learn more about the reproductive aspects of mares and mare… Read More »

Early Equine Embryology

Posted: | December 13, 2020

Embryology – Different Stages of the Early Equine Pregnancy – Equine embryology – early pregnancy images. A pictorial showing embryonic developmental images through to the fetal stage of 50 days. All day numbers given here are the number of days post-ovulation on the conceiving cycle. The 32 to 64 cell stage of a developing embryo is the morula.… Read More »

Early Embryonic Death (EED) – what it is and why it may happen

Posted: | December 3, 2020

Early Embryonic Death – Noted reproductive veterinarian Dr. Jon Pycock explores early embryonic death in the mare and some possible resolutions to the problem. By Jonathan F Pycock, BVetMed, PhD, DESM, MRCVS, RCVS Specialist in Equine Reproduction For all horse breeders, it is important to realize that not every mare will give birth to a live foal. Failure… Read More »

Is my mare Overdue? The Perennial Panic!

Posted: | November 13, 2020

Is my mare overdue? – A question frequently asked by concerned owners and discussed here with possible answers and statistics related to gestational durations. By Jos Mottershead Note: Please review the statistics at the foot of this page. If you have gestational duration information on your born-live colt or filly foal, please add it and assist us in… Read More »