Why Do Dogs Get Stuck During Mating? A Vet Explains Why It Happens and What to Do

Cuteness may earn compensation through affiliate links in this story. Learn more about our affiliate and product review process here.

Why Do Dogs Get Stuck During Mating?

Puppies are adorable whether they are purebred or complete mutts. However, like all baby mammals, puppies only come about as a result of sexual intercourse which results in a successful mating. Canines — including wolves, foxes, jackals, and dogs — are unique in how they mate since before the act is over, the two dogs get stuck together in what's known as a copulatory tie.


Image Credit: dageldog/E+/GettyImages

Video of the Day

Why do dogs get stuck together when dogs mate?

Dogs get stuck together during mating because the glans bulb on the male dog's penis swells following ejaculation while the female's vaginal muscles contract to prevent withdrawal.

Video of the Day

Getting stuck like this is normal dog behavior. To understand the entire process, you first need to know more about the erectile tissue of the penis. All mammals have two types of erectile tissue; one stiffens the penis, and the other fills the penis glans and makes the organ swell.


In most mammals, these tissues are both activated simultaneously, but in dogs, the penis is stiffened before intercourse begins, and the penis does not begin to swell until the two dogs start mating. Male dogs have a bone in their penis, so they have very little penis-swelling tissue, and their penises do not grow much until after sex begins.


Once the male pooch has mounted the female and entered her, the glans tissue begins to expand, particularly around the base in an area called the bulbus glandis. As the male ejaculates, the penis starts expanding dramatically. When the bulbus glandis swells, it becomes very stiff and grows three times as wide compared to when flaccid. At the same time, the female's vaginal muscles start tightening and squeezing down on the penis.


The male dog usually dismounts during the tie, leaving the two dogs locked together butt to butt. They will become unstuck only once the male's penis deflates and the female's vaginal muscles relax.

Evolutionary benefits of the copulatory tie in dogs

Why dogs remain tied together as part of their natural mating process is still a mystery, but there are some theories. For example, while the male has already ejaculated sperm into the female, scientists speculate that during the tie, the dog ejaculates a small amount of prostate fluid, which may help push his sperm further into the female, increasing the likelihood of pregnancy.


The tie may also help prevent other dogs from mating with the female until the male's sperm can enter the egg. As for why they face opposite directions, this could be a defensive tactic that allows them to survey all 360 degrees of their surroundings.


Image Credit: Wirestock/iStock/GettyImages

How long do dogs stay stuck after mating?

The copulatory tie typically lasts 5 to 20 minutes, but it is not unusual for it to last 30 minutes or longer.


The length of time mating dogs can remain stuck together can vary. In some cases, it can go on for an hour. The dogs will not be able to separate until the male dog's bulbus glandis returns to its original size.

Can neutered dogs still get stuck if they try to copulate?

Yes, neutered dogs can still copulate and tie.


Neutered dogs still have a fully functioning penis, and some will continue to respond to a female during her heat cycle. Although neutered male dogs have lower testosterone levels, which usually results in a lower sex drive, they are still capable of copulation. Neutering only prevents pregnancy.

Image Credit: Carmen Schwarz / 500px/500px/GettyImages

How to help stuck dogs

If you see two dogs stuck together following mating, do not interfere.

While female dogs sometimes start crying, whimpering, or even growling or barking, this is a natural process. Occasionally, dogs will panic, especially if they are inexperienced or it is their first time. If you are familiar with the dogs, comforting and encouraging them to stay calm will reduce stress until the tie has broken naturally.


Separating them may seriously injure both dogs and cause unnecessary stress. Eventually, the male dog's penis will return to its normal size, the female's vagina will relax, and the two dogs can go their separate ways.

Even if you are upset because you did not want the dogs to breed, you should not try to break them up, as the male has already ejaculated. If fertilization has occurred, there is nothing you can do to stop it. Attempting to separate the dogs will only risk hurting them. If the mating was unintentional, dog owners should talk to their veterinarian about options for preventing pregnancy.

An anti-progestagenic injection, called Alizin, can be used to terminate the pregnancy. But this veterinary product is approved for use only in certain European countries and not the U.S. If this injection is given within 22 days of the mating, it is 100 percent effective. Its efficacy will weaken after that time period. The most effective way to terminate the pregnancy and to prevent further accidents is to have your female dog spayed.

The bottom line

Getting stuck in a copulatory tie is a natural part of the canine mating process. If you ever see two dogs stuck together, do not try to separate them, as this will be painful and can cause injury. Once dogs are tied, ejaculation has already occurred, so separating them will not reduce the likelihood of pregnancy. If the mating was unintentional, seek veterinary advice once the dogs have separated naturally. If you do not want your male dog to mate or your female dog to get pregnant, talk to your veterinarian about the right time to have them spayed or neutered.


Report an Issue

screenshot of the current page

Screenshot loading...