Page 941 - The Veterinary Care of the Horse

days to full term.

VetBooks.ir Management of the in-foal mare

Once the pregnant mare is back at home, she will still require the following.
• Daily inspection.

• Regular hoof care.

• Appropriate feeding.

• Regular worming.

• Dental care.
• Vaccination. An influenza and tetanus booster 3–6 weeks before foaling gives the foal

maximum protection. If the mare is to be vaccinated against equine herpesvirus, this
should be done in the 5th, 7th and 9th months of pregnancy. Vaccination of mares to

protect their foals from diarrhoea caused by equine rotavirus is carried out in the 8th, 9th
and 10th months of pregnancy.

• Exercise. This depends on many factors such as the size, age, condition and fitness of the

mare and the weight of the rider. Strenuous exercise should be discontinued from the 6th
month of gestation. The brood mare should be turned out each day.

Pregnancy failure

FAILURE TO CONCEIVE AND EARLY EMBRYONIC LOSS

This can be due to the following.
• Genetic factors, e.g. chromosomal abnormalities. Defects may occur if mating and

fertilization do not take place at the optimum time and either the sperm or the egg is
‘aged’ (beginning to deteriorate in quality).

• Environmental factors: malnutrition of the mare and overfeeding or underfeeding in the
period after mating can adversely affect her fertility. Any illness resulting in a high

temperature or prolonged colic can cause embryonic death.

• Uterine factors: any problem with the previous pregnancy such as a difficult birth or
retained placenta can adversely affect the uterine environment in a subsequent pregnancy.
The presence of endometrial cysts can sometimes affect embryonic development as can

the presence of fluid retained in the uterus after mating. All mares experience a transient
uterine inflammation after mating but this usually resolves within 48 hours. In older

mares the inflammation may last for a longer time, and the embryo cannot survive under
these conditions.