New frontiers in chromosome elimination-mediated doubled haploidy breeding: Focus on speed breeding in bread and durum wheat

Rectovaginal lacerations in the mare occur during parturition when the foal’s limb(s) or head are forced caudal and dorsal. The injury is seen predominantly in primiparous mares and is usually due to violent expulsive efforts by the mare (Colbern et al., 1985; Turner and McIlwraith, 1989). The injury is also seen following forced extraction of a large fetus or extraction before full dilation of the birth canal. Third-degree perineal lacerations occur when there is tearing through the rectovaginal septum, the musculature of the rectum and vagina, and the perineal body.