During the violence of foaling, and with dystocia, various tissues may be torn. The anatomy of a malpositioned foal can do
damage. "If the foal's feet are not positioned correctly, they can damage the cervix and the vaginal vault, and they even
can go up dorsally and penetrate through into the rectum," says Wolfsdorf. A foal's feet may come out of the mare's rectum
instead of out of the vulva. This scenario may be more common in maiden mares because they haven't relaxed as well and don't
dilate as well. "But these injuries are repairable," Wolfsdorf states.
Other kinds of complications are commonly seen but are less severe, including rectovaginal tears, which can occur when a Caslick's
procedure has not been reversed prior to foaling or from a large foal. This kind of tear occurs when the foal tears the mare's
vulva lips or perineal body, which can develop into a rectovaginal fistula. Other injuries can also occur like bruising post
foaling or vaginal and cervical tears. These may have consequences to a mare's fertility, especially with cervical tears,
but they are not generally life-threatening.
Another common foaling complication is colic from colon torsions. "We're not sure why it happens exactly," Wolfsdorf says,
"but there's a belief that once the mare has had the foal, there is increased space in her abdomen. So she starts eating more
because there's less pressure on her stomach. This may result in an increased buildup of gas that causes the colon to torse."
With early diagnosis and prompt surgical correction, successful outcomes are possible. But if diagnosis is delayed, it may
have a devastating outcome.
Complications associated with straining are not necessarily as common but are equally severe, such as rectal or uterine prolapse
postfoaling. Tears in the vagina can also allow the small colon to protrude through the vulvar lips. It's not common, but
it is serious, with serious implications.
Foaling should be uncomplicated, but the force of the act, or the unusual positioning of the foal, may change the outcome
dramatically. Being prepared for the range of possible complications or injuries is essential to mare and foal wellbeing.
Ed Kane, PhD, is a researcher and consultant in animal nutrition. He is also an author and editor on nutrition, physiology and veterinary
medicine with a background in horses, pets and livestock. Kane is based in Seattle.