How Long Do Boxers Stay In Heat?

Wanna know how long Boxers stay in heat?

Great! We got you covered.

If this is your first time owning a sexually intact female Boxer, you will want to understand how her period works.

image of White boxer dog sleeping on a purple rug near the burning fireplace. Resting dog.

Most importantly, knowing the timing of her heat cycle is crucial should you wish to avoid unplanned pregnancies!

In this DigDoggy article, you will learn:

  • When a Boxer experiences her first heat cycle
  • What differentiates proestrus and estrus
  • How to read the signs that your Boxer is going into heat
  • Why a female Boxer may mount toys or other dogs
  • When a Boxer can get pregnant

And much more!

What's In This Guide?

How Long Does A Boxer Stay In Heat?

A Boxer’s heat cycle lasts about three weeks and sometimes, a month.

You might assume dogs bleed for that entire time, but they don’t. The bleeding only lasts a week or so.

Once the bleeding eases up, the second stage of the dog heat cycle begins.

New owners often make the mistake of thinking their dog’s menstruation is over at this point but this stage is actually when your Boxer can get pregnant.

This window of fertility lasts about a week.

What Should You Know About Boxers In Heat?

When it comes to Boxers in heat, there are a few things that may surprise you.

Your Female Boxer May Perform Masculine Behaviors

As with any dog, a Boxer’s heat cycle is a long process.

Proestrus, also known as the “preparation phase” can last anywhere between nine to 17 days.

During this stage, estrogen levels rise and cause the eggs stored within the ovaries to mature. The vaginal walls also thicken in preparation for sexual intercourse, thus causing bloody discharge.

Males will be attracted to the female Boxer, but she won’t allow mating during this period and may even respond hostilely towards her suitors. Her vaginal walls are not ready nor are her eggs.

Testosterone levels are relatively high at the end of proestrus and may cause your lady pooch to act masculine behaviors, such as humping stuffed toys.

Your Female Boxer Is Most Fertile When The Bleeding Stops

The bloody discharge that defined proestrus stops and this can be a trap for new owners who mistakenly think that once the bleeding stops, the cycle is complete.

In reality, this phase is the best time to get pregnant; it is when your Boxer is most receptive and submissive to males.

During estrus, the eggs are released from the ovaries, and progesterone rises. The estrogen that peaked during proestrus abruptly declines.

Breeding A Boxer During Her First Heat Has Its Risks

Although your dog’s first heat cycle indicates sexual maturity, it does not imply that she is mentally and physically prepared to be a mother.

Dams tend to have labor problems than dogs that were bred later, ideally during or after their third heat.

Should you wish to breed your boxer, you should ensure her development first so that she could cope best with pregnancy and motherhood.

When Do Boxers Enter Heat?

Boxers can get pregnant at a surprisingly young age!

Six to twelve months is the most common timeframe for the initial season in Boxers.

However, some Boxers may fall outside of this range for various reasons.

I’ve heard a few Boxers that went into heat as early as four months, while others were as late as 15 months.

The takeaway is that there is no correct age for your Boxer to enter heat. She can be early, average or late.

The best thing you can do as an owner is to prepare and learn the signs that your dog is entering heat.

image of female boxer dog lying down in pain while in heat

How Often Do Boxers Go Into Heat?

On average, female Boxers cycle into heat every six months. Your lady pooch will go into heat throughout her life unless you have decided to have her spayed.

However, the length of time between will increase as your dog gets older. The duration and length of the elapse between heats can be irregular in young puppies.

With experience, you will become more adept at recognizing the onset of this natural life cycle.

What Are The Signs That Your Boxer Is In Heat?

When a female Boxer enters a heat, the first sign is an enlarged vulva caused by an uptick in estrogen. Other signs include bloody discharge and enlarged nipples.

Behavioral changes also occur when your lady pooch is in heat, such as:

  • Excessive licking of the vagina
  • Frequent urination
  • Loss of appetite
  • Mood swings
  • Scent marking
  • Tail flagging

Unusual changes in behavior are caused by a sudden shift in hormonal balance. Your lady pooch may feel irritable, nervous, or distracted.

But as soon as the bleeding stops, your female Boxer will become receptive to male canines. Your lady pooch may even initiate sexual contact by raising her rear towards a potential mate and deflecting her tail to one side.

These social behaviors may continue until the estrus cycle is over.

What Affects A Boxer’s Heat Cycle?


Spaying a female Boxer either through ovariohysterectomy or ovariectomy prevents her from experiencing an estrus cycle, thus your lady pooch will never get pregnant at all.

You will want to spay your dog after she finishes her first heat cycle. Better yet, consult with your vet about the best timing for the surgery.


Medications like prednisone may cause delayed heat cycles.

Prednisone is a steroid medication given by mouth or injection. A powerful drug, it is used in emergencies such as anaphylactic reactions, spinal cord trauma, and many forms of shock.


Malnutrition, hormonal imbalances, genetic disorders, infections, and other health problems also cause abnormal heat cycles in Boxers.

Final Thoughts On Boxers In Heat

Heat cycles are not much different from a human’s menstruation period. Our lady pooches can get mood swings, too!

Overall, keeping an intact female Boxer comes with responsibilities and some hassle, but you can manage it with knowledge and planning.

Don’t forget that males will do almost anything to get access to your Boxer in heat. So be sure to take more precautions.

Picture of Rachael Summers

Rachael Summers

Rachael Summers is the Founder and Senior Editor at Dig Doggy. She is a lifelong canine enthusiast and adores dogs of all shapes and sizes! Rachael also loves iced coffee, hammocks, and puppy-cuddling!

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Rachael Summers is the Founder and Senior Editor at Dig Doggy. She is a lifelong canine enthusiast and adores dogs of all shapes and sizes! Rachael also loves iced coffee, hammocks, and puppy-cuddling!

About Dig Doggy

DigDoggy® is a free resource for dog owners, with everything from expert product reviews to trusted pet care advice.

All of our reviews and recommendations are based on unbiased research by our editorial team. Read more about us.

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