The short answer to this highly philosophical question is: yes. A dog can get pregnant by more than one dog. When female dogs are in heat, there is no stopping them from mating with more than one male dog.
There’s no stopping them from doing anything during this time, really. This period of heat (pun not intended) can last anywhere between 18 and 24 days – for some dogs this will be longer or shorter.
During this time, anything can happen. Whether you are planning for a litter or not, a bitch in heat will deliberately want to cater to her maternal instincts, meaning it is entirely possible for her to mate with more than one dog.
How a dog can get pregnant by more than one dog at the same time
During the ovulation stage of her heat (which we will explain later), a bitch that has already mated with another dog will have other eggs that can still be fertilized.
The most popular form of organising a stud, where you can literally pay for a male dog of your choice to mate with your bitch.
Sounds awful, but it isn’t unethical and is actually helpful for planning a birth and puppies. Say, for example, you have a purebred female Labrador and you would like a purebred Labrador father.
Or, you have a purebred Labrador and you would like Labradoodle puppies, so you can look for a Poodle father.
If your bitch has escaped and found another male, or perhaps bumped into one in the park, it is possible for them to mate and for another egg to be fertilized.
Of course, the mating process is fairly lengthy and obvious, so a human has the power to try and stop it before the locking occurs, which we will explain in further detail later.
If this occurs, this is called heteropaternal superfecundation. This means multiple eggs can be fertilized around the same time from more than one father or sperm. This can happen in humans, too.
What happens when a female dog goes into heat
Bitches go into their heat cycle twice a year, so there are two windows of possible pregnancy each year.
Although dogs cannot communicate with us about their bodily functions, it is obvious when a bitch goes into heat from a change in her behaviour.
They tend to get lazier, urinate more often, either take extreme interest or disinterest in male dogs, and will either be super affectionate or grumpy.
This is known as the proestrus stage, the first stage of the cycle that also includes tail wrapping around the vulva, which usually swells up. There will also be signs of bloody discharge. This usually lasts around 9 days.
The estrus stage is when a bitch is most likely to get pregnant. They will suddenly take a lot of interest in male dogs. Her previously tucked tail will move slightly to the side and she will get flirty.
The once bloody discharge will begin to clear, which is one of the biggest indications that she is ready to mate. This also can last up to or more than 9 days.
The diestrus stage lasts between 60-90 days, and is when the dog is no longer fertile. Basically every symptom and behaviour change will gradually slow down and disappear.
The final stage is the anestrus stage is the longest stage, lasting between 100-150 days, and marks the end of her cycle until the next one arrives.
If your young bitch is showing signs of going into heat, it’s worth consulting a vet for beginners who have no idea what is going on.
We recommend keeping a close eye on your dog, especially during the estrus stage, because she will scout out any male dog, neutered or not, for mating. Likewise, they will smell her scent. If you don’t want puppies, you can consider spaying her.
The Mating Process
Mating can happen whenever, but the chances of pregnancy will occur in the second stage of heat when the discharge starts to clear. Without going into detail about how dogs mate, the most crucial part is actually the ending.
It’s going to sound and look really odd, but it’s completely natural. The final stage of mating is often called “locking” or “tied”, when the reproductive parts of each dog will appear…stuck.
The dogs may be stood back-to-back or in another position for a while. This is to ensure fertilization. Of course, if the male dog is neutered this won’t be an issue. Just remember to never try and separate them, because that could cause injury.
Whilst dog pregnancy tests do exist, finding out whether a bitch is pregnant is a waiting game. Symptoms include:
- Loss of appetite
- Change of behaviour
- Enlarged nipples
- Weight gain
- Swelling of abdomen and often a darker color
So….will the puppies have two fathers?
Because female dogs in heat have absolutely no filter and will try anything for a mating session, there’s no way of telling that there will only be one father of a litter unless you have kept an eye on her consistently.
Unless you know she has mated more than once, you won’t know until the puppies are born and have grown a bit. If there are two fathers, signs will include:
- Size differences (if the two fathers were of different sizes this will be obvious)
- Physical appearances
- Trait differences as the puppies grow
If you do think your bitch has produced a mixed litter, this isn’t a bad thing! It isn’t dangerous and will not affect the health of the puppies or bitch. The one downside is that if you were wanting purebred puppies, this may not happen with more than one father.
Fortunately, the pregnancy process, from heat to mating to birth, is very natural and bitches usually do everything themselves. If you want professional help, a vet will have the best advice, but it’s usually best to let your bitch do her thing.
At the end of the day, bitches are natural maternal figures and puppies are adorable regardless of their parental heritage.