Dogs in Heat: How Long It Lasts and What to Expect

You've probably heard the phrase “dog in heat." But if you aren't tuned-in to dog health topics and a dog's reproductive cycles, it may sound a little confusing.

Female dogs that haven't been spayed will go into “heat," or estrus, twice a year.¹ By knowing what to look for and how to deal with your dog when she is in heat, you can be prepared and ensure she's getting extra supervision and TLC from you and the family.

4 Phases of a Dog's Heat Cycle

There are four different phases of a dog's heat cycle: proestrus, estrus, diestrus and anestrus.

1. Proestrus

The dog's vulva will swell and she will have blood-tinged discharge or some bleeding due to the estrogen hormone being produced. Estrogen peaks one to two days before estrus.²

Your dog may bleed from six to 11 days during this heat phase. She might start being more playful with male dogs but not interested in breeding.²

2. Estrus

This part of a dog's heat cycle can last between five and nine days.² Her bleeding will slow down or stop, and the vulva will be enlarged.³ Your dog will also likely have vaginal discharge, as well as a luteinizing hormone surge due to increasing progesterone and decreasing estrogen during this phase.²

She will give off pheromones that male dogs can smell miles away. She will want to seek out male dogs and mate; you might notice restlessness. You may also notice mounting behavior, and she might want to mount your leg, other dogs or objects.⁴

This is her fertile time.³ Keep her away from non-neutered dogs if you don't want her to get pregnant.

3. Diestrus

Your dog will not be interested in mating.² This heat phase lasts about 60 days whether or not she is carrying puppies.³ She will have an increase in progesterone for the first four weeks and then it'll taper off at the end of this stage of the cycle.³

4. Anestrus

This is the time when your dog is not in heat and her body is preparing for her next possible pregnancy. It should last several months — usually four months — depending on the breed. Her vulva is no longer swollen and there should be no discharge.³

Other common signs a dog is in heat

Here are additional signs you might observe:⁴

• Some dogs have loose stools when they are in heat.
• Other dogs get an upset stomach due to hormonal changes.
• Some female dogs in estrus lose their appetite temporarily since they are focused on looking for a mate.
• Dogs may experience mood changes due to hormone fluctuations.

How Long Are Dogs in Heat?

The first three stages of a dog's heat cycle last about four months.² Most dogs will experience two full heat cycles per year, roughly one every six months.¹

Some factors that may influence the duration of a dog's heat cycle include:

• Age. The cycles can start anywhere from when your dog is 6 months of age to 24 months.² The time between cycles tends to be longer as a dog ages, and the typical breeding ages tend to be between ages 2 and 9.¹
• Presence of a male dog. If you have a non-neutered male in the house, that tends to bring heat on faster with female dogs. Keep non-neutered puppies separated from each other from ages 4 months on.⁵
• Breed. Some breeds, like the basenji and the Tibetan mastiff, average only one cycle a year.²

Tracking your dog's estrus cycles is important as a pet parent. If her estrus cycles aren't consistent, talk to your vet, as your dog might be having a health issue you should be aware of.

Tips to Help Comfort a Dog in Heat

When your dog is in heat, she might be feeling a bit hormonal and temperamental. That can look like anxiety or needing extra attention.⁴ Here are some tips for comforting a dog in heat:

• Give your dog extra hugs, love and time.
• Take her on leashed solo walks to help get some energy out.
• Make sure you give her more opportunities to go out if she's urinating more frequently.⁵
• Don't leave her outside unsupervised. Stray dogs looking to mate can hop the fence.
• You might want to keep her in a limited space in the house during the proestrus phase when she's bleeding.
• Try doggie diapers to address bleeding accidents.⁵
• Clean up her area, like her bed, often and make it comfortable for her.
• Have patience if she seems moody, aggressive or unlike herself.
• Keep her away from public areas where she'll likely encounter male dogs.⁵

Preparing for Your Dog's Heat Cycle Will Go a Long Way

It's important to be aware of when your dog goes into heat so you know what to expect from her physically and behaviorally. Mark it in your calendar and then set a reminder for about six months from now so you'll be on the lookout.

You'll have to keep a close eye on your dog when she is in heat and try to keep her away from non-neutered male dogs if you don't want her to become pregnant. Consider keeping her in a specific area of the home with floors that are easy to clean and care for when she's bleeding. If it seems like your dog is in pain or very uncomfortable while in heat, talk to your veterinarian.

Overall, practice patience and give your dog extra cuddles and attention. This can help you both manage how long she is in heat as best you can.

CareCredit Credit Card Financing for Dogs

The CareCredit credit card provides a convenient way to pay for your dog's vaccinations and other health and wellness expenses, including exams, medications and products at providers in the CareCredit network.* Continue your wellness journey by downloading the CareCredit Mobile App. You can find a provider on the go, manage your CareCredit account and easily access the Well U blog for more great articles, podcasts and videos. Use our Acceptance Locator to find a veterinarian that accepts CareCredit to help keep your pet healthy and happy for a lifetime of love.

In addition to pet care, you can also use your CareCredit credit card for dentistry, cosmetic, vision, hearing, health systems, dermatology, pharmacy purchases, spa treatments and so much more within the CareCredit network. How will you invest in your health and wellness next?

Author Bio

Diana Kelly Levey is a freelance journalist, content marketing writer and author with more than 15 years of experience covering health and wellness.