If you have an unspayed dog, you may be nervous and wonder, “can dogs get pregnant when not in heat?” Having an unplanned litter can be stressful and emotional, especially when finding good homes for the puppies.
Female dogs in heat are emotionally delicate and should have food, water, and a calming bed in their own space. But if your dog is not in heat and not spayed, you may still be nervous. After all, “silent heats” are possible, where the dog shows no signs of being in heat.
Understanding our dog’s reproductive cycle is important to be good doggie parents. But remember, we promote responsible spaying and neutering, as this is the best way to avoid adding to the problem of dogs in shelters.
So, Can dogs get pregnant when not in heat?
Dogs cannot get pregnant until they’re in heat, during which they breed to birth puppies (whelp). Even then, they are only fertile during one part of the heat, when they are in estrus, not the entire time. Intact females can only get pregnant about 2 to 3 times yearly when their estrus or heat cycle occurs.
Many people want to breed their dogs simply because they love them and love the idea of a houseful of puppies! But breeding is an intense commitment, where breeding dogs need to be extensively health tested and picked for breed traits like the right temperament, conformation, and ability.
Responsible breeders are rare and hard to come by, and if you have a female dog, it’s always best to spay before her first heat, which usually arrives between six months and a year.
Luckily, it’s pretty obvious when most dogs are in heat, so you can take the necessary precautions to avoid pregnancy if your dog is not spayed. These include being more receptive to males, among other symptoms, which we discuss later in the article.
Note that dogs don’t get pregnant during their entire estrous cycle. Dogs cannot get pregnant during the diestrus phase of their cycle, even if you notice slight discharge then. Keeping track of your dog’s “seasons” is the best way to know when they can or cannot get pregnant.
Can a Dog be Pregnant and in Heat at the Same Time?
Technically, dogs can be pregnant and in heat at the same time. Since a dog has many eggs that are fertile during the estrus stage of about 10 to 14 days, she can conceive in that time and still be in heat and able to conceive again. This is how some litters can have different fathers.
But after roughly two weeks of estrus, they enter the diestrus phase, where they are no longer fertile, but they may be pregnant. Implantation and the later stages of pregnancy, marked by belly swelling, occur when a dog is in the diestrus cycle.
By the time a dog is past the estrus stage of the heat, they’re less receptive to males, and mating ends. The signs of being in heat wane at this stage, and your dog appears to get back to normal until pregnancy signs appear.
Dogs can experience a phantom pregnancy after estrus, where they have pregnancy symptoms even though they aren’t pregnant. Dogs with this condition will exhibit restlessness, nesting behavior, and physical signs of pregnancy, like enlarged mammary glands without milk production.
Can a Dog be in Heat and not Bleed? How to Tell if Your Dog is in Heat
Your dog can be in heat and not bleed if they experience a silent heat cycle. Bleeding is the most prominent sign of estrus in female canines, but some dogs don’t exhibit this symptom. These dogs will still be receptive to male dogs and can get pregnant upon mating.
Your dog may also bleed so little that you don’t see hte the bloody discharge. This is especially common in small breeds and canines that clean themselves exceptionally well.
Studies suggest that not having enough of the hormone progesterone can cause silent heat in animals. A split heat is another culprit in dogs being in heat and not bleeding. Here, the proestrus stage occurs, and bleeding starts, but the heat suddenly stops and resumes weeks or months later.
Split heat is most common in younger females whose pituitary glands don’t produce enough LH hormone. Abnormalities in the heat cycle of dogs typically improve as the dog gets older, but it sometimes means that a dog is infertile.
Don’t confuse a silent heat for a missed heat which can be a sign of hypothyroidism, malnutrition, ovary tumors, and ovarian hypoplasia.
Signs That a Dog is in Heat
These signs are seven signs that a dog is in heat, varying depending on the stage in the heat cycle.
- Swollen and enlarged vulva.
- Bloody discharge — Darker during proestrus that gets lighter and eventually watery as a dog approaches the estrus stage. Some suggest that dogs get period cramps, causing discomfort.
- Increased licking of the genitals.
- Behavioral changes — where female dogs are more receptive to females.
- More frequent urination.
- Unwanted attention from other dogs — The pheromones and scents in the urine alert male dogs of your dog’s reproductive stage.
- Changes in appetite — Most female dogs have a poorer appetite, while others get more ravenous.
Dog Heat Cycle Calculator: When Can a Female Dog Get Pregnant?
A female dog can get pregnant when their heat cycle starts, and they mate with a male. You can use the following guidelines to calculate when your dog may come into heat. Remember that some dogs have irregular heat cycles, but these may stabilize with age.
A Heat Cycle or Estrous Occurs in Four Stages in Dogs:
1. Proestrus (Lasting 5 to 10 Days)
The body prepares to mate in the proestrus stage, which typically lasts for about nine days but can be shorter or longer. You’ll start noticing signs of heat, like an engorged vulva and bleeding, but they usually are not interested in males at this stage.
The female dog will not allow a male to mount her during this stage and can get aggressive if they attempt to.
2. Estrus (Lasting 7 to 14 Days)
Estrus is the active stage of the heat cycle. After the transition from proestrus, female dogs will allow males to mount them. Contrary to popular belief, bloody discharge turning watery isn’t a sign that the heat cycle is complete. It actually indicates the period a bitch is most fertile during estrus.
In addition to a swollen vulva, you’ll notice increased urination as your dog marks readiness to breed.
3. Diestrus (Lasting 14 to 140 Days)
This stage follows your dog’s fertile stage. Here a dog either gets back to normal or develops pregnancy. Your dog’s vulva will reduce in size until it’s normal, and your dog’s attitude toward males will normalize.
4. Anestrus (Typically Lasting Six Months)
An inactive phase between the next heat cycle that lasts about six months. Smaller dogs have a shorter anestrus, while large dogs have a longer one.
What are the Chances of a Dog Getting Pregnant on the First Heat?
The chances that a dog can get pregnant on their first heat are very high. Most dogs experience their first heat at about six months, but smaller dogs have it earlier. Large and giant dogs may only have their first heat between 8 and 18 months, with 8 to 10 months being typically for a large breed like a Bullmastiff.
It’s best to avoid pregnancy on first heat because the dam isn’t mentally or physcially ready for a litter and can pass on bad genetics. This is because health tests like hip dysplasia can’t be done before the dog is two years old, so young dams are likely not fully health screened for breeding.
Can a Puppy Get Pregnant Before First Heat?
A puppy can’t get pregnant before their first heat cycle because they’re not yet sexually mature. It’s unlikely to miss your puppy’s first heat cycle since they’ll probably leave blood everywhere. You likely missed the signs if your young dog is pregnant and didn’t see them in heat.
Will Dogs Mate When not in Heat?
Dogs display mounting behavior sometimes when not in heat, but they will not mate. Dogs will sometimes mount each other when they are playing or to assert dominance. But this is not the same as mating.
Male dogs can sometimes display humping behavior, especially if they are not neutered, but this is also not the same as actual mating.
The urine of a female dog in heat will show a male that they’re ready to mate. Without the scents and pheromones present during the heat cycle, dogs will not mate.
Frequently Asked Questions
Do dogs get pregnant easily?
When can a dog get pregnant after bleeding?
Will neutered dogs mate?
You can read more in our article on how many litters a dog can have in their lifetime.
Conclusion
Dogs need to be in heat to get pregnant because their bodies are ready to handle pregnancy at this time. Estrus is the stage where female dogs accept males and mate, while diestrus is when their bodies prepare for pregnancy. Puppies can get pregnant as soon as they experience their first heat cycle but are fat from being ready to raise them.
Meet Your Experts
Author
Tamsin de la Harpe has nearly two decades of experience with dogs in rescue, training, and behavior modification with fearful and aggressive dogs. She has worked closely with veterinarians and various kennels, building up extensive medical knowledge and an understanding of canine health and physiology. She also spent two years in the animal sciences as a canine nutrition researcher, focusing on longevity and holistic healthcare for our four-legged companions. Tamsin currently keeps a busy homestead with an assortment of rescue dogs and three Bullmastiffs.