Category Archives: pregnancy

Diagnosis of Placentitis

Posted: | November 19, 2023

Diagnosis of Placentitis – Are Inflammatory Markers Useful? Placentitis is – literally and practically – “inflammation of the placenta” (“itis” as a suffix indicates inflammation). Use of assays for inflammatory markers in the mare – in particular Serum Amyloid A (SAA) – have been previously suggested as possible diagnostic tools for use in the identification of placentitis. Inflammatory… Read More »

Estimate Fetal Age

Posted: | October 15, 2023

A New Method to Estimate Fetal Age in the Mare Sometimes there arises a need to estimate fetal age in the mare, for which a breeding date perhaps is unknown. Several methods have been previously identified, such as measurement of the fetal eye[1][2], or biparietal diameter, eye approximated volume, fetal aortic diameter and femur length[3], among others. These… Read More »

Altrenogest Effect on Progesterone

Posted: | October 7, 2023

Is it True Altrenogest Has an Effect on Progesterone Production? Pregnant and embryo recipient mares are often treated with supplemental progestins – commonly Altrenogest in the oral form Regumate, or injectable in one of several longer-acting commercial preparations – in an expectation of “low progesterone” levels. There is a significant question as to what number should be applied… Read More »

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 Horse Breeding Training 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 horse breeding training. Perhaps they do not own stallions but want to learn more about the reproductive aspects… Read More »