Skip to Content

How Long Does a Dog Stay in Heat? Estrous Cycles Explained (2023)

This site is supported by our readers. We may earn a commission, at no cost to you, if you purchase through links.

how long does a female dog stay in heatAre you wondering how long a female dog stays in heat? Most pet owners don’t know the answer, but understanding estrous cycles is essential for keeping your pup healthy and happy. Knowing how to recognize signs of heat, when pregnancy is possible, and preventive measures like spaying can help you provide the best care for your furry friend.

We’ll cover all that, plus considerations for first heats and truths about first litters, so that you’re prepared every step of the way.

Key Takeaways

  • Onset of heat in female dogs typically occurs between 6-24 months of age, depending on the breed size.
  • The length of a female dog’s heat cycle can vary, but it generally lasts for about 4-13 weeks, with toy breeds having shorter cycles compared to giant breeds.
  • During heat, female dogs may exhibit signs such as a swollen vulva, bloody discharge, increased urination, marking, strong odors attracting males, high activity, nervousness, and seeking more attention from owners.
  • Preventing accidental pregnancies can be achieved through options like using diapers and supervision during heat, spaying the dog before 6-7 months old, scheduling spay before the first heat if possible, or using a mismate injection within 48 hours.

When Do Cycles Start?

When Do Cycles Start
You’ll likely see your pup’s first heat cycle between 6-24 months, depending on breed size. Smaller breeds often start earlier than larger ones. Some primitive breeds don’t have a defined breeding season and instead follow their own irregular cycles as they reach a certain age.

Young females may have longer intervals between each cycle or multiple cycles per year, while giant breeds might only go into heat once annually.

The estrus stage is typically 10-14 days long, but the entire cycle can last up to 13 weeks with great variation in individuals and different breeds of dogs. Ovulation occurs at this time along with a light bloody discharge that indicates the highest risk for pregnancy if mismating happens during this period.

To be sure you avoid accidental matings, consider spaying before she reaches six to seven months old or schedule it before her very first heat if you want to prevent any pregnancies from occurring in the future.

How Often Do Cycles Occur?

How Often Do Cycles Occur
Most dogs have two heat cycles per year, but small breeds may experience three and giant breeds may only have one.

  • Toy breeds like Chihuahuas and Yorkies may cycle up to 3 times annually.
  • Medium dogs like Beagles and Corgis average twice a year.
  • Mastiffs, Great Danes, and other extra large breeds tend to have just one heat cycle per year.

Pay attention to the signs of heat in your dog to monitor her cycles. Note when she starts swelling and spotting to track cycle length and identify the fertile period. This helps dog owners prevent accidental matings and litters of puppies. With vigilance, you can better manage her heat cycles.

What Are the Signs of Heat?

What Are the Signs of Heat
When a female dog enters heat, her body sends out several signals that alert owners to the change. The first and most obvious sign is usually a swollen vulva; this can be accompanied by a bloody discharge that may vary in color and amount over the course of the cycle.

Additionally, you might notice an increased level of urination or marking behaviors, as well as strong odors designed to attract male dogs. By paying attention to these signs of heat, you can track your dog’s cycles more effectively and prevent accidental litters.

Bloody Discharge

When your pup starts her cycle, look for a change in the discharge—it can be the first sign of heat. The bloody discharge is usually seen during the proestrus phase of your pet’s estrus cycle and typically lasts between nine to eleven days.

  1. Increased urination
  2. Marking behaviors with scent
  3. Swollen vulva
  4. Odor to attract males
  5. Strong desire for attention from owners

As these signs become more pronounced, you will know she has officially entered into heat, lasting an average of 10-14 days depending on breed and age!

Strong Odor

As your pup begins her cycle, you may notice a strong odor that serves to attract males. This musky scent signals fertility and primes males for breeding. Be alert for potential unwanted attention. Monitor your pet closely and keep intact males at a distance during this time. Her pheromones are potent and the goal is preventing accidental pregnancy.

Day Discharge Amount
1-4 Sparse, red
5-9 Heavy, bloody
10-14 Tapering off
15-20 Minimal, clear

What’s the Typical Cycle Length?

The typical dog heat cycle usually lasts between 4-13 weeks, so be sure to keep an eye on your pup’s behavior during this time.

Here are a few things you should know about the doggie estrus:

  1. Female dogs experience estrus when they reach six months of age or older, depending on breed size. Giant breeds may even take up to 12 months before their first heat cycle begins.
  2. Great Danes and other large breeds generally have longer cycles than smaller varieties like Chihuahuas and Pomeranians.
  3. Allowing too many consecutive heat cycles can increase the risk of mammary cancer due to prolonged hormonal changes that occur during each individual cycle.
  4. Lastly, it’s important to remember that while some owners choose delayed spays for larger breeds due to perceived health benefits from allowing one full reproductive season, accidental matings can still result in unwanted pregnancies! Monitor your pet closely throughout her entire estrous period and discuss all options with your veterinarian beforehand if you’re uncertain what path is best for both parties involved.

When is Pregnancy Possible?

When is Pregnancy Possible
Pregnancy is most likely to occur during the light bloody discharge associated with ovulation, which occurs within estrus. To be certain your pet won’t experience any possibility of unwanted litters, doggie diapers and careful monitoring by pet parents are essential throughout her entire cycle.

For normal size breeds, this usually lasts between 4-13 weeks; however, large breeds may take up to twelve months before their first heat begins.

The best way to prevent pregnancy is spaying before 6-7 months old or scheduling a procedure prior if possible in order for all parties involved—pet included—to stay safe and healthy long into adulthood.

How to Prevent Pregnancy

How to Prevent Pregnancy
As a pet parent, it is important to be aware of the various options available for preventing pregnancy in your female dog. Spaying before 6-7 months old or scheduling the procedure prior can help ensure that all parties involved remain safe and healthy long into adulthood.

Additionally, mismate injections may also be administered within 48 hours if needed; however, this method should always be discussed with your veterinarian first.


Spaying is the most effective way to prevent unwanted pregnancies and ensure your pet’s long-term health. During her estrus cycle, you may notice increased whining or nervousness. She may also leave behind bloody stains on furniture and floors.

To protect against mismating, keep a baby gate up in between rooms when not supervised and watch out for signs of heat like a swollen vulva or strong odors that attract males.

Spay before 6-7 months old to guarantee safety from accidental matings while still allowing proper development for larger breeds who benefit from their first heat cycle. With spaying, comes peace of mind knowing your pup won’t be contributing to the overpopulation problem.

Mismate Injections

Mismate injections may be an option if you find yourself in a situation where your pup has been exposed to mating within 48 hours. These injections are typically administered in the early days of the pet’s estrus cycle and can help prevent pregnancy during this fertile period.

Knowing when your canine is ready to enter heat and understanding their menstrual cycle can help you stay one step ahead should you need these injections as protection.

Considerations for First Heat

Considerations for First Heat
Before making the decision to delay your pup’s spay, consider the risks associated with her first heat cycle. As a pet parent, it’s important to know that female dogs reach puberty between 6-24 months, depending on breed.

Their estrus cycles may vary greatly in length and frequency, especially if there is a great distance from an older dog’s cycle. Typically, a pet’s estrus cycle consists of four phases: proestrus (swelling), estrous (ovulation & receptivity), diestrous (dropping off), and anestrous (resting).

The final active phase, known as ‘heat’, can last anywhere from 10-14 days, with intervals averaging 6-8 months apart for most breeds. However, small breeds may experience 3 cycles per year, while giant breeds only have one.

It’s important to keep track of when this happens to prevent unwanted pregnancies or ensure that your pup receives proper care during each phase breakdown.

Truths About First Litters

Truths About First Litters
You’re misled if you let your pup have her first litter. Female dogs reach puberty between 6-24 months, depending on breed size and with no breeding season except some primitive breeds. Smaller breeds may experience three cycles per year, while larger ones may only cycle once a year, typically over a 4-13 week period of time.

During this pet’s estrus cycle, there are four phases: proestrus (swelling), estrous (ovulation & receptivity), diestrous (dropping off), and anestrous (resting). When the final active stage known as ‘heat’ occurs, it can last 10 to 14 days for most dog’s cycles; however, intervals in between these stages vary from breed to breed.

Allowing your pup to go through her first heat is not necessary medically or socially, considering it puts them at risk for unwanted pregnancies as well as contributing towards the overpopulation problem – spaying increases their lifespan too!

Keeping track of when she goes into heat is important in order to ensure that she receives proper care during each phase breakdown so that she has a healthy cycle moving forward.

Benefits of Delayed Spaying

Benefits of Delayed Spaying
Although spaying is generally recommended before your pup’s first heat, delaying the procedure may be beneficial for certain larger breeds. Giant breeds often have pronounced differences in their pet’s estrus cycle compared to smaller ones, and some northern breed dogs may even benefit from an extra homemade treat or two during this time.

Research has shown that allowing these big pups to go through a single heat can help them reach peak maturity and maintain better weight control throughout their life.

However, it should still be noted that while delayed spaying might offer benefits if done correctly, there are also risks associated with leaving your giant pooch unspayed too long such as accidental litters or unwanted pregnancies – so always discuss options with your veterinarian beforehand.

Tracking Her Cycle

Tracking Her Cycle
Now that you know the benefits of delayed spaying for certain large breeds, it’s time to discuss tracking her cycle.

While small dogs may have two or three cycles per year, giant breeds can take up to a full calendar year in between estrus cycles. It is important to keep track of when your pup goes into heat so you can plan ahead and provide appropriate care during this time.

Quirky behaviors such as increased urination and marking are common signs that she has begun her cycle – but most reliably spotted will be a spot of bloody discharge from the vulva which indicates that ovulation has taken place.

To make sure all your bases are covered, petMD’s Michael Kearley recommends keeping an accurate record on a calendar each month with any changes noted – this way if anything looks out of the ordinary in subsequent heats then you’ll know about it right away!

Frequently Asked Questions (FAQs)

What is the average age for a female dog to reach puberty?

Female dogs reach puberty between 6-24 months, depending on the breed. Small breeds tend to cycle earlier than large ones, and young females often have irregular intervals.

Are there any breeds with a breeding season?

You’re right, some breeds like Basenjis and sled dogs cycle seasonally in the spring. However, most breeds can cycle year-round, with small breeds having up to three cycles annually. It’s important to monitor heats and prevent accidental breeding regardless of breed.

How long can sperm survive in the reproductive tract?

Sperm can survive in the reproductive tract for up to 7 days. Female dogs stay in heat anywhere from 4-13 weeks, but this varies by breed and individual. Keep track of your dog’s cycle and separate her from intact males during heat to avoid accidental matings.

Are there any medical benefits to allowing a female dog to have her first heat before spaying?

Have you ever wondered if there are medical benefits to letting a female dog have her first heat before spaying? Though it may benefit large breeds, experts agree that the overall health and population control advantages of spaying outweigh any potential positives.

Are there any special considerations for tracking a female dog’s heat cycle?

Track your female dog’s heat cycle closely to avoid surprises. Note the start date, any changes, and its length. Separate her from intact males for safety and use panties or diapers for cleanliness. Coincidentally, this will also help monitor if there are any medical benefits of allowing her first heat before spaying.


Surprisingly, female dogs can remain in heat for four to thirteen weeks. Understanding the estrous cycle is key to helping a female dog stay healthy during this time. To ensure her safety, it’s important to track her cycle start date, changes, and length, as well as separate her from intact males.

Spaying before six to seven months old is the best option to prevent an accidental mating and avoid health risks associated with heat cycles. While allowing a female dog to experience one heat cycle can be beneficial for some large breeds, it’s still ideal to spay her as soon as possible.

By keeping these points in mind, you can ensure that your female dog stays healthy and safe during her heat cycle.

Avatar for Mutasim Sweileh

Mutasim Sweileh

Mutasim is the founder and editor-in-chief with a team of qualified veterinarians, their goal? Simple. Break the jargon and help you make the right decisions for your furry four-legged friends.

Valerie Bullard

Monday 30th of May 2022

My dog is bleeding hard this time she never did this.


Wednesday 16th of June 2021

I never got a response. Lots of stages but I needed to know the days from beginning to end.

Comments are closed.