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Can Large Breed Dogs Mate With Small Breed Dogs

Can large breed dogs mate with small breed dogs? Yes, they can. Like other animals, dogs have strong mating drives and if an intact male (one who has not been neutered) is in the vicinity of a female in heat for long enough then mating is likely to be attempted.

Of course, there can be challenges with large dogs and small dogs mating. If a small female dog becomes pregnant by a large male dog the mating process itself can cause injury or even death and the puppies may be too large for her to carry safely.

And a smaller male may have trouble mounting a larger female, so that is not always a viable option.

If breeders want to mate dogs that are highly mismatched in size, what’s usually done is to artificially inseminate a large breed female with the sperm of a small breed male. This is a much safer way to breed two very different-sized dogs, as the larger female will be able to carry the smaller puppies easily.

The Pets Tome has an interesting article on a Chihuahua Mastiff mixed breed, believe it or not!

Challenges with Mating Large Female Dogs with Small Male Dogs

The biggest challenge that small male dogs have in mating with larger female dogs is reach. The small male dog may need to stand on a platform to be able to penetrate and mount the larger female dog.

A platform is something that will obviously require human intervention, but that doesn’t mean that the mating process won’t work.

After the smaller dog mounts the larger female, then they will go through the process of locking.

When the smaller male dog locks with the larger female you may need to help him turn around during the locking process. It’s important to be very gentle during this maneuver or you can hurt the male dog.

Dogs that are the same size normally do this “tied” maneuver on their own, but different size dogs will need some help.

You also need to make sure he has a place to stand that is even with the female’s vagina. The locking process can take up to 45 minutes, so you need to be patient.

Remember to hold the larger female still during this process so that she isn’t dragging the male dog around by his penis.

Challenges with Mating Large Male Dogs with Small Female Dogs

There are several challenges with mating large male dogs with small female dogs, including during the process of mating, the pregnancy, and the birth of the puppies.

The Process of Mating

There are challenges with pairing a small female with a large male start during the mating process. It is possible for a large male dog to damage a smaller female dog during that process.

A large male can overwhelm a female when attempting to mount her. His weight alone can cause damage to the female’s spine. Pawing – which sometimes gets aggressive while mating – can do damage to a much smaller female dog.

If the male is larger than the female, damage can also be done to the female’s reproductive organs due to the male’s organs being too large for her to accommodate. She can experience tearing and bruising.

After the dogs form a lock, the male can potentially also drag a smaller female around because she doesn’t have significant enough weight to keep the larger dog in place. The lock can last between 15 and 40 minutes.

With dogs that are the same size, the male will turn away from the female during the lock, but that doesn’t always happen when the female is significantly smaller in size.

It’s important if you see this happening to keep the dogs very still and make sure he doesn’t squash her. Don’t try and separate the dogs. Let the lock complete.

Finally, after the lock is complete the male may flop down on the smaller female causing damage.

Overall, it’s far better for dogs of similar sizes to mate. The process is a lot less risky.


Puppy size is largely an average of the size of the parents. If a small female dog and a large male dog mate, then the female can have trouble carrying the puppies because of their size.

A female dog’s uterus is sized to carry puppies that are her size, not those of a much larger dog. The larger puppies can cause physical distress in a smaller female.

If you are in the situation of a large male impregnating a much smaller female, then you should work with your vet to monitor her pregnancy for safety.


Because dogs created by mismatched size pairings of a large male with a small female tend to be larger than what the female can safely deliver, C sections are often necessary.

This is an expensive procedure, but large puppies may not be able to fit through a smaller female dog’s birth canal.

Preventing Mismatched Size Mating

The only way you can guarantee that dogs won’t mate is to get them spayed or neutered. An intact female dog will sometimes try to escape when she is in heat and find a male to mate with.

You don’t need to wait until a dog goes into heat to spay her. You can spay and neuter dogs at about 6 to 9 months of age.

If an intact male dog smells a female in heat, he will try to find and mount her. Intact males can smell a female in heat from quite a distance away.

If you have a female dog in heat, make sure she is supervised and there are no intact male dogs around her. You can buy dog clothing that can help stop the mating process, but it’s not foolproof.

In Conclusion

If you want to breed a large dog with a much smaller dog, it’s best to have the large dog be a female. This way, the puppies can be safely carried and born with no difficulties due to size.

You’ll then be able to enjoy your puppies, who will hopefully have the best traits of both parents!

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