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Can a dog get pregnant during her first heat?

Many dog owners want to breed their dog, and wonder when is the right time. Others simply want to wait until their dog reaches sexual maturity before spaying, which means allowing her to go through a heat cycle. These owners worry about unintended pregnancy. 

Can a dog get pregnant during her first heat?

Yes, she can. However, whether she should is another matter entirely. There’s lots of controversy and conflicting advice when it comes to many facets of dog ownership and breeding. However, there is a consensus when it comes to when you should allow your female to breed. It’s unwise and potentially dangerous to breed your female during her first heat. 

Dog Heat Cycle

The dog’s heat cycle begins with proestrus. During this time, she will begin to bleed. Male dogs will be attracted to her, but she will not be receptive to them. This stage can last from 4-20 days. The average length is about 9 days. 

The next stage is estrus. This is the stage when the female can get pregnant. Her vulva will be swollen, and discharge may change from bloody to yellow, or stop entirely. She will be receptive to males in this stage, and breed with any available males. 

This stage lasts from 5-13 days, with peak fertility lasting 3-4 days. 

Next, is diestrus. If she is pregnant, the pregnancy will last 60-64 days. If she is not pregnant, the diestrus stage lasts 60-90 days. Hormonal changes occur during this time. 

The last stage is anestrus. During this stage, hormone levels return to their preheat state. This stage lasts about 90 days. 

When Does a Dog Have It’s First Heat? 

Dogs can go into heat between 6-18 months of age. Small breeds go into heat earlier, typically between 6-8 months old. Large breed dogs go into heat about 18 months of age. Rarely, a large breed dog may be 2 before she enters her first heat. 

How Often Does Heat Occur

How often females go into heat also depends on their size. The average is two cycles a year. However, some small breeds go into heat three times a year. Some large breeds have one heat a year. Despite this, dogs are known as monoestrus, instead of polyestrus. 

During the first few heat cycles, females are often irregular. After about two years of heats, they settle into a regular pattern. 

Signs of Heat

The first sign of heat is typically a swollen vulva. However, owners often miss this in the early stage of heat. After all, it’s not an area we are accustomed to inspecting on our pooches. 

Bloody discharge is often the first sign owners notice. It is possible for the discharge to not appear until the cycle is well underway. Owners can also miss the discharge. Females will clean themselves often during heat, and may lick the discharge away before the owner sees it. It’s often first observed on the floor or furniture. The owner then tracks the source to their pooch. 

Another sign of heat is increased urination. Females may also mark by urinating. This is a well known behavior in male dogs, but females also use urine to mark their territory. In addition to marking, urinating can also send signals to males in the area. 

Males can smell a female in heat. In fact, they can smell a female from up to 3 miles away. If there are any intact males nearby, you can expect male visitors once your female begins her cycle. Even if she is kept indoors, males will howl, bark, and otherwise make life difficult until she is out of heat. 

It can be frustrating, but it’s part of their natural instinct. During the time when she’s fertile, the female may lose her appetite. She may also seem nervous or anxious. It’s natural for her to focus on the desire to breed, and have little interest in anything else. This includes eating and playing. Once the estrus cycle is finished, she should return to her typical behavior. 

Can a dog get pregnant before her first heat?

No, a dog can not get pregnant unless they are in heat. This is the time when they are fertile. Some owners may mistakenly believe their pooch got pregnant before their first heat. 

It’s likely that the owner simply missed the signs she was in heat. This is a fairly common occurrence, especially with the first heat. If the owner isn’t closely watching for signs, it can easily seem like she got pregnant before her heat. 

Is it dangerous for a dog to get pregnant during the first heat?

To put it simply, yes. It is dangerous for your dog and their puppies if she becomes pregnant during her first heat. 

Behavioral Concerns

A female simply isn’t mentally and emotionally prepared to care for puppies at a young age. If she has puppies too early, she is more likely to reject them. She is also more likely to accidentally harm or kill them. 

She doesn’t have full control over herself and her behavior yet. She’s still a pup herself, and not mature enough for puppies. It is also more psychologically stressful when a mother has pups too early. 

Physical Concerns 

At under 18 months to 2 years of age, your dog is still developing physically. Imagine attempting to grow babies while your own body was still growing. It’s easy to see how taxing it would be on your body. It’s the same for your dog. 

If her body is still developing, it does not need the added stress of pregnancy and breastfeeding. It’s possible for it to affect her longterm health, because of the strain on her body. Miscarriages are also more common, for the same reason. Her body is simply not prepared. 

Pregnancy takes a toll on even a mature dog. Many experts recommend not breeding a female back to back, to allow her body to have time to recover from the labor and caring for her pups. When her body is not ready, the toll can be much higher. 

Why Do Dogs Come Into Heat at a Young Age? 

You may be wondering, if a dog shouldn’t have puppies during ehr first heat, then why does she go into heat at such a young age? The answer may lay partly with her diet. 

Dogs who are fed a raw food diet, similar to what they would eat in the wild, go into heat later than those who are fed commercial dog food. It’s possible the food causes them to mature faster than nature intended, at least sexually. 

Wolves do not have their first heat until 2 or 3 years of age. This suggests that diet, or a combination of diet and selective breeding, may be why dogs today go into heat before they are ready for pregnancy. 

Ensuring Healthy Dogs

It’s recommended to test for health conditions before breeding your female. This ensures that she doesn’t have genes that could have a negative impact on pups, and the breed in general. 

Some of these tests can’t be performed until she is 2 years of age. This makes it impossible to be sure she is healthy enough to have healthy pups during her first heat. 

Her personality will not be fully developed during her first heat, either. You want to avoid breeding a female with a bad temperament, and this won’t be completely clear until she’s at least 18 months of age. 

There are many issues that don’t show up in young dogs, if they show up at all. This is why waiting and testing your pooch ahead of time are essential for quality puppies. 

Avoiding Pregnancy During Heat

The sure fire way to avoid pregnancy during heat is to get your dog spayed. However, this isn’t always an option, particularly if you want to breed her at a later date. So, how do you keep her from getting pregnant? 

Essentially, you’ll need to keep her under constant supervision. It’s best to keep her inside, even if your yard is fenced in. Dogs can show incredible ingenuity when it comes to breeding. 

When she is outside, keep her on a leash at all times. No matter how well trained she is, it’s possible she will take off to find a mate. 

Doggie diapers can help limit the smell and the mess, but they must be used alongside supervision, not in place of it. 

What to Do If Your Dog Gets Pregnant

Accidents happen. Even the most responsible pet owners can’t foresee every possible scenario. If your dog has an accidental pregnancy, you have two basic options. 

Confirming Pregnancy

Your vet can confirm a pregnancy at 3 to 4 weeks after mating. A blood test can be used to detect relaxin, a hormone that occurs during pregnancy. If the test is negative, it should be repeated in one week to be sure. An ultrasound can also perform pregnancy at 4 weeks or later. 

It’s important to find out if your dog is pregnant as quickly as possible. This gives you options to keep or terminate the pregnancy. Late-term abortions can be performed, but they are riskier. Some vets will only perform them if the health of the mother is in serious jeopardy.

Allowing the Pregnancy 

Some owners choose to allow the mother to have the puppies. Before you make this decision, you should be sure that both you and your pooch are prepared. If your dog isn’t healthy and physically mature enough, abortion can be the more humane option. 

You’ll need to be prepared to care for the puppies until you can find them suitable homes. There’s a higher risk of the mother rejecting puppies if she gets pregnant during her first heat, so you’ll also need to be prepared to care for the puppies without the mother if necessary. 

Do you have the time and financial resources to care for puppies? Can you find them suitable homes? Do you have the space for the puppies? These are important considerations. 


There are a few ways to terminate a dog’s pregnancy. Spaying is one option. If performed early in the pregnancy, the procedure is much the same as a traditional spay. When the reproductive organs are removed, the puppies are terminated as well. 

If you want to leave your female intact, Prostaglandin is an option. This is a progesterone injection that essentially halts the pregnancy hormones. This causes the termination of the pregnancy. It’s most effective when used in the first 22 days of pregnancy, but can be administered up to 45 days into pregnancy. 

Dexamethasone is another option. This is a steroid injection that can terminate the pregnancy. 

These methods can have side effects, but they are continued relatively safe. 

Late term abortions can be performed with abortion medication or surgical abortion. However, these are riskier and require a greater recovery time.