Getting stuck together during mating is such a normal thing for dogs that it even has its own medical name. It is called a “copulatory tie” and is also seen in wild canines such as wolves and foxes.
It happens because a section of the erectile tissue at the base of the male dog’s pen** called the bulbus glandis gets very engorged with blood. This happens after the pen** is inserted into the female and is triggered by the male dog thrusting.
The bulbus glandis swells very rapidly and soon measures more than two times the diameter of the rest of the shaft of the pen**. As a result, it gets stuck inside the female’s vagi** (birth canal).
At the same time, the circular muscles at the entrance to the female dog’s vagi** (the constrictor vestibuli muscles) contract and prevents the pen** from moving back out. This results in a very secure lock and the dogs are tied together.
What Role Does the Copulatory Tie Play in Breeding?
To understand this, we need to consider normal mating behavior in dogs. This usually starts with a male dog sniffing a female dog to check that she is on heat and therefore receptive to mating. However, she may also display her willingness to mate by presenting her butt in his direction and holding her tail to the side.
Once the male dog mounts her and begins to thrust he has a first discharge during which a pre-sperm discharge is released from his pen**. It is after this that the bulbus glandis swells and the female dog’s constrictor vestibuli muscles contract.
After dismounting but whilst still in the copulatory tie, the male dog finally discharge the post-sperm fraction of the discharge. This can take anything from 5 to 30 minutes.
What Does a Copulatory Tie Look Like?
Once the male dog has discharge, he dismounts the female and turns around at a 180-degree angle so that the dogs are now facing in opposite directions. However, his pen** is still ‘locked’ inside the female.
They look like two dogs that have their butts glued together. It sounds quite comical but is very alarming if you have not seen it before or have no idea what it is. Dogs can stay like this for over half an hour.