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Dog Health & Care

When Do Border Collies Go into Heat? Vet-Approved Facts & Tips

Rachael Gerkensmeyer
By Rachael Gerkensmeyer · Reviewed & fact-checked by Dr. Paola CuevasVet Approved
Dr. Paola Cuevas
Reviewed & Fact-Checked byDr. Paola CuevasVeterinarian
Dr. Paola Cuevas is our Senior In-House Veterinarian at Dogster and Pangolia. She has over 19 years of experience working with an array of species and loves sharing her knowledge and experience with our readers and aims to provide assistance with any issue presented by your non-human family members. She received her degree from the University of Guadalajara, Mexico.View authorThe information is current and up-to-date in accordance with the latest veterinarian research. Learn more
Updated on June 17, 2026
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sad and worried border collie dog lying on a wood floor

Border Collies are fun, loving dogs, but this is not your average dog breed. They require a great deal of attention, care, and commitment from their human companions and would prefer to have some kind of job. Owning a female Border Collie also means preparing for and managing their heat cycles if they are not spayed.

Most Border Collies have their first heat at about half a year old, though this is not a fixed rule. Some Border Collies can go into their first heat earlier than the 6-month mark, while others can experience their first heat later, around the 1-year mark. There is no right or wrong timeline here.

Female Border Collies that go into heat “early” or “late” can be just as healthy as those that go into heat at the average 6- to 8-month mark. Having an idea of how your Border Collie's heat cycles work and the signs of said cycles will help ensure that you’re prepared to offer proper care and attention as necessary.

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How Often Do Border Collies Go into Heat?

The typical female Border Collie will experience a heat cycle twice a year, about 6 months apart from one another. That said, some dogs go into heat only once a year, while others go even longer between heat cycles. Many things go into the timing of a dog’s heat cycle, including size, diet, lifestyle, and health. It may take a few cycles before timing gets into a rhythm, and owners can accurately predict when a cycle will begin. It is important to keep in mind that unlike humans, dogs do not go through menopause and will have heat cycles throughout their entire lives.

Image By: Elayne Massaini, Shutterstock

What Are the Stages of a Border Collie’s Heat Cycle?

Four stages make up a Border Collie’s heat cycle, and it is important to understand each one in order to properly care for and protect your dog from unwanted pregnancies.

Stage 1: Proestrus

This first stage of the heat cycle generally lasts between 7 and 10 days. During this time, the female’s body is preparing itself for insemination and ovulation. The proestrus stage may produce bloody discharge from the vulva. Most females are not interested in mating at this point, so they may become aggressive toward males that try to mate.

Stage 2: Estrus

The estrus stage is when a female Border Collie is fertile and can successfully mate with a male. This stage tends to last between 5 and 10 days, and during this time, a female may seek out a male to mate with.

Stage 3: Diestrus

This stage usually takes 10 to 90 days. The hormonal changes will cause the female to no longer be receptive to the male. Depending on the events that occurred during the estrous cycle, the female could be pregnant or not.

Stage 4: Anestrus

This is the longest stage of a Border Collie’s heat cycle, as it is the resting stage. The anestrus phase lasts from the last day of diestrus to the first day of proestrus, no matter how long that might be. At this time, your dog should display no signs of being in heat.

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What Are the Signs That a Border Collie Is in Heat?

When a Border Collie goes into heat, her hormones lead to both physical and behavioral changes, albeit temporary ones. When a female goes out of heat, these changes subside and are typically eliminated.

Image By: Tepepa79, Shuterstock

If your dog shows one or more of the following signs, it could indicate that she is going into heat:

  • Vulva swelling and redness
  • Pink color or bloody discharge
  • Anxiety
  • Increased vaginal licking
  • Mood swings
  • Submissive or aggressive behavior
  • Agitation
  • Frequent urination
  • Changes in body odor
  • Energy level changes
  • A different tail stance
  • Blood spots on bedding

Most female Border Collies exhibit at least one sign of being in heat, but all dogs are different. Some may exhibit multiple signs, while others just one or two. Some will show different signs than others, even if they’re siblings.

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How Should a Border Collie Be Cared for While in Heat?

It is important to take special care of your Border Collie while she is in heat to avoid unwanted pregnancies and to ensure her comfort throughout her cycle. Here are several tips that you can use to ensure your dog’s health, happiness, and safety.

1. Don’t Allow Outdoor Time Without Supervision

Even if your yard is fully fenced, you should never let your female Border Collie outdoors without complete supervision while she is in heat. Males that are not confined can detect females in heat, and they will do whatever they can to get to the females they find. Your dog isn’t safe in her own yard while she’s in heat. Your dog might even try to escape in hopes of finding a mate while she is in her estrus stage. Keeping a leash and/or eye on her will help ensure that she doesn’t escape and that other dogs won’t intrude into your property.

Image By: sonsart, Shutterstock

2. Never Allow Off-Leash Exploration

Even if your Border Collie is usually great at staying by your side while outdoors, she should not be trusted when she is in heat. Even when she wants to be good and obey your commands, her hormones can drive her to do the opposite if it means finding a mate to reproduce with. Therefore, you should always keep a leash on your dog whenever you are in public settings, and stay away from dog parks at all costs.


3. Keep Cleaning Supplies Handy

Chances are that things will get a bit messy while your dog is in heat. She is likely to have a bloody discharge that can get on the floor and other items in your home. She may also leave blood spots behind on her bedding and anywhere else she lies down. Therefore, it is a good idea to keep paper towels and disinfectant handy so you can clean the messes as they happen. Some owners prefer to use “doggy diapers” during the heat cycle to keep messes to a minimum.

Image By: Mironov-Shutterstock

4. Incorporate More Activities into the Day

It is always a good idea to incorporate more activities and “brain games” into her day. Border Collies are active dogs, anyway, so leaving them to their own devices while in heat could spell trouble. Spending time playing fetch, hide-and-seek, and with puzzle toys can help keep your dog busy and distract her from the possible discomforts of her heat cycle.


5. Practice Patience

A Border Collie in heat can have mood swings and behave aggressively toward other animals living in the household. It’s important to practice patience when dealing with unwanted behaviors, as punishing her won’t work and is simply unfair. Her actions are completely normal, and she deserves space and understanding during her heat cycle.

Image By: Ayla Verschueren, Unsplash
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In Conclusion

Now that you know when your Border Collie should have her first heat, how often she will go into heat, and the signs to look for that indicate that her heat cycle has arrived, you can plan, prepare, and take proper precautions to ensure that she will have a long, happy, and healthy life. The first few heat cycles can be overwhelming, but things should get easier and more streamlined as time goes on.

Sources

Featured Image Credit: Elayne Massaini, Shutterstock

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Rachael Gerkensmeyer
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