Page 919 - The Veterinary Care of the Horse

heritable and should be important considerations when selecting the mare and stallion.

Mares should be selected for quality of type or performance and not simply because they
VetBooks.ir are no longer suitable for any other purpose. Those with serious conformational defects
should not be bred from as soundness is very important.

• Are suitable facilities available? Consideration must also be given to the facilities

required. You will need a foaling box and suitably fenced good-quality pasture. Ideally
the field should be shared with another mare and foal.

• Can I afford it? Stud fees, livery charges and routine and unexpected veterinary bills
can add up to a substantial sum and there is no guarantee that a healthy foal will be

produced or that the foal will mature into a quality horse.

General information

Most mares have a 21-day oestrous cycle. This is divided into:

• oestrus (average 5 days)

• dioestrus (14–16 days).

The cycles begin at puberty (approximately 18 months) and continue throughout the mare’s

life.

OESTRUS

The mare is receptive to the stallion and is said to be ‘in season’ (Figure 19.5).

Typical signs of oestrus include:
• adopting a urinating stance with the tail raised and passing small squirts of urine (Figure

19.6)

• opening and closing the vulval lips; this is known as ‘winking’ (Figure 19.7).