Page 938 - The Veterinary Care of the Horse

the same day as the donor or up to 3 days after the donor mare. The maturation of the follicle

of the donor mare is monitored and when ovulation is imminent, the mare is mated or
VetBooks.ir inseminated and injected with an ovulation-inducing hormone. The mare is then monitored
by ultrasound examination to confirm that ovulation has occurred. Blood samples may also

be taken to check that the progesterone concentrations are rising.

Embryo recovery

This is carried out on day 7 following ovulation. At this stage the embryo is in the uterus and
can move around freely. Following careful preparation of the mare to reduce the risk of
bacterial contamination, a sterile embryo-flushing catheter is introduced into the uterus. A

special embryo flushing medium is allowed to flow into the uterus by gravity. An inflatable
cuff prevents the fluid or catheter escaping from the uterus. The fluid is then drained from the

uterus by gravity, passing through an embryo filter. This process is then repeated and the
fluid in the filter is examined under the microscope for the presence of an embryo.

Embryo transfer

If a healthy embryo is retrieved, it is transplanted into the recipient mare. The embryo is
transferred through the cervix of the recipient mare using a special insemination pipette and

gently squirted into one of the uterine horns. The mare is treated prophylactically with
antibiotics. Alternatively, the embryo may be transplanted in a semen straw with an

insemination gun.

CARE OF THE BROODMARE FOLLOWING COVERING OR

INSEMINATION

Pregnancy diagnosis in the mare

There are a number of procedures used to confirm that a mare is in foal.

RECTAL PALPATION

This can be done at any stage from day 14 to 15 after ovulation (16 to 17 after covering)
onwards. The vet assesses the tone, size and position of the uterus which change as the
pregnancy advances. The foal may be felt from around mid-pregnancy. The vet may inspect

the cervix which is usually whiter and much more tightly closed than the cervix of a non-