Why Do Dogs Get Stuck After Mating?

This is known as “tying up”.  This happens near the conclusion of normal mating and can last up to an hour or so.  Usually the male turns around and the dogs stand tail to tail.  It occurs because the female has a sphincter muscle at the junction between the vagina and the vestibule called the cingulum or constrictor vestibularis.  This sphincter contracts proximal to the swollen bulbus glandis of the male’s penis.  Do not attempt to separate the dogs during this time, as it can cause injury.   It is thought that this tying up helps fertilisation.