Equine Physiology Workbook

Fetal development may be affected by:

 Time of breeding – mares bred earlier tend to have longer gestation periods than those bred later in the summer  Nutrition – well fed horses have gestation days shorter than those fed poorer quality feed  Breed, mare & stallion – each breed and individual mare and stallion may have influence over gestation length  Foal sex – not proven

Parturition

Maternal indications include; mammary gland development up to 6 weeks prior to foaling, colostrum developing 2-3 days prior to foaling, waxing 6-48 hours prior to foaling, relaxation of the sacroiliac ligaments, relaxation & softening of the vulva and surrounding soft tissue, change in belly shape of the mare and tail position.

85% of foaling occurs at night meaning that mares have some influence over birthing.

Stages of Labour: Stage 1:

 Restlessness, abdominal pain, sweat patches in flanks and elbows  Relaxation & dilation of cervix  Onset of uterine contractions  The cervical star is present through the cervix and ruptures, releasing the allantoic fluid

Stage 2:

Forcible straining

Lying down & raising again Amnion is present with feet Foal delivered within 30 minutes

Stage 3:

 Expulsion of fetal membranes within 4-6 hours  Mares not encouraged to get up (could result in retained placenta)  Umbilicus contains a significant amount of blood. It is not cut. It will break naturally when the mare stands

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