Page 934 - The Veterinary Care of the Horse

mating. If he is particularly aggressive, the mare may wear a protective neck cover.

VetBooks.ir HYGIENE

Prior to covering, the external genitalia of the mare will be washed with warm water to
remove any faecal contamination. Her tail is normally bandaged to prevent the stallion’s

penis contacting the hairs. Assistants likely to have any contact with the external genitalia of
either the mare or the stallion must wear clean, disposable gloves.

MATING

The mare is normally taken into the covering area first and held so she can see the stallion

approaching. The stallion is then led to the mare from behind her on her left side,
approaching at an angle of approximately 45 degrees. He will normally sniff and tease the

mare for a short period before mounting her. As he mounts, the tail may be held out of the
way by an experienced handler standing on the mare’s right side. If necessary, the penis can

be guided into the mare. Mating usually last for about 1 minute, but this varies between
individual stallions. When the stallion ejaculates, his tail will be seen to move up and down
and a pulse of fluid can be felt along the base of the penis by the handler holding the mare’s

tail. Following ejaculation, the stallion should be allowed to dismount slowly and then be
backed away. The penis is then washed with clean warm water.

THE TIMING OF COVERING

Covering should occur at the optimum time to maximize the chances of conception. Mares
are routinely teased every other day prior to mating to establish when she comes into oestrus.

On average, the oestrous period lasts for 5 days and ovulation will take place 24 hours before
the end of oestrus. The aim on most studs is to cover the mare the day before she ovulates
and to cover them just the once. The mare may be injected with hormones to induce

ovulation. Regular veterinary examination is helpful to establish the optimum time. On the
day after mating, the mare should ideally be re-examined by the vet to check whether she has

ovulated and that there is no fluid in the uterus (see page 628).

TEASING

Following a successful mating and confirmation that the mare has ovulated, teasing is

recommenced and carried out every other day from about day 14 after covering. If she does
not return to oestrus by day 15–17 after covering, she will be presented to the vet for

scanning to determine whether she is in foal.