Dogs
Mar 21, 2025
If you’ve just spotted a bit of blood on the floor or noticed your female dog acting a bit off—maybe more clingy, restless, or suddenly the centre of attention for every male dog in the neighbourhood—you’re not alone. It can be a little confusing (and even a bit scary) the first time your dog goes into heat. This phase, often called a female dog’s period cycle, is totally normal.
Just like humans, a female dog’s period cycle is just part of how her body prepares for possible pregnancy. But knowing what to expect—and how to care for your female dog during this time—can make all the difference.
In this blog, we'll explain the signs, the stages, how long it lasts, and what you should (and shouldn’t) do when your dog is in heat.
What Is a Female Dog’s Heat Cycle?
A female dog’s heat cycle is her natural way of getting ready to have puppies. It’s often called the female dog period cycle, though it’s different from what humans go through.
When a female dog is “in heat,” her body is preparing for the chance to mate and become pregnant. You may notice blood spots, a swollen vulva, or changes in her behaviour—like acting more clingy or restless. Some dogs may seem more playful or start lifting their tail to the side when touched near their back end.
When Do Female Dogs First Go Into Heat?
Most female dogs go into their first heat between 6 and 12 months old, though some may start a little earlier or later. Small breeds often begin sooner, or as early as 6 months, while larger breeds may only have their first period cycle when they’ve hit 18 to 24 months old. This is something to keep in mind when choosing the right dog breeds, especially if you’re a first-time owner or want to plan around the timing of their development.
If your puppy is around that age and you’ve started noticing small spots of blood, or she’s suddenly got every male dog in the park sniffing around her, chances are she’s starting her first cycle.
How Often Do Dogs Go Into Heat?
Most female dogs go into heat twice a year, or about every 5 to 11 months. It’s different for every dog, and some might only have their period cycle once a year, especially certain breeds like Basenjis or Tibetan Mastiffs.
If your dog’s still young and is experiencing her first heat, her cycle might be a bit irregular in the beginning. Over time, most dogs settle into a more predictable pattern.
Tracking your female dog’s period cycle can be helpful if you're trying to avoid pregnancy or if you're thinking of spaying her at the right time. You can do so by marking the dates on your calendar when you notice signs of heat, like spotting or a change in mood.
The 4 Stages of a Female Dog’s Period Cycle
The female dog's period cycle is made up of four stages, and each one affects your dog in different ways. Knowing what happens in each stage helps you understand her behaviour, how to care for her, and when it’s safe to walk her or consider spaying.
Stage 1: Proestrus
Proestrus is the start of the heat cycle. It’s also when most people first notice something is going on.
The main sign is usually bloody discharge from your dog’s vulva. You might also notice swelling in that area, and she may start licking herself more than usual. She’ll attract male dogs during this time, but she won’t be ready to mate yet.
Behaviourally, some dogs become more clingy or a little grumpy. Others act completely normal. The proestrus stage usually lasts 6 to 11 days, but it can vary.
If your dog is going through proestrus, it’s best to keep her away from male dogs and give her extra comfort and care at home. Puppy pads, dog nappies, or washable bedding can help keep things clean.
Stage 2: Estrus
Estrus is the fertile stage—the time when your dog is able to become pregnant.
Her discharge may change colour (it often becomes lighter, like pinkish or straw-coloured), and she may now be more welcoming to male dogs. During this stage of a female dog’s period cycle, you might notice her lifting her tail to one side—this is called “flagging”, which means she’s ready to mate.
Estrus usually lasts around 5 to 9 days, though it can be shorter or longer. This is the time to be very careful if you’re not planning to breed. Keep her on a leash during walks and never leave her alone in the garden.
Stage 3: Diestrus
Diestrus starts when your dog is no longer interested in mating—even if a male still shows interest, she’ll turn him away.
Her body now acts like it’s pregnant, whether she is or not. Hormone levels stay high, and you might notice changes like tiredness, increased appetite, or even nesting behaviour. This can last anywhere from 60 to 90 days, depending on her cycle.
During the diestrus stage of your female dog’s period cycle, things will usually go back to normal at home. Her discharge stops, and any swelling goes down. If you’re not sure whether she’s pregnant or you’re worried about anything unusual, a vet check can give you peace of mind.
Stage 4: Anestrus
Anestrus is the resting stage. It’s the break between heat cycles, and it usually lasts around 4 months.
In this stage of a female dog’s period cycle, hormones are low, and there are no signs of heat. Your dog will act like her usual self, and you don’t need to take any special steps unless you're planning a spay or breeding in the future. This is the time her body resets.
Anestrus stage is often the calmest part of the female dog's cycle, giving you both a breather before the next one.
Signs That Your Dog Is in Heat
The most common signs that your dog is in heat are physical changes and shifts in behaviour. These signs are part of the natural female dog's period cycle, and they help you know when her body is starting to prepare for possible mating.
Knowing what to look out for can save you a lot of worry—and help you respond calmly when things change.
Physical symptoms
The first sign most owners notice is a bloody discharge. It might show up as tiny drops on the floor or in her bed. Some female dogs clean themselves often, so you may not see much, but you’ll likely spot some discharge if you check gently.
Another clear sign of the onset of a female dog’s period cycle is a swollen vulva (the area under her tail). It may look puffy or larger than normal. This happens because of changes in her hormone levels—it’s a normal part of the heat cycle and not usually painful.
You don’t need to panic when you see these signs. It’s just her body going through something natural, and with a little extra care and cleaning, you’ll both get through it just fine.
Behavioral shifts
Many dogs go through small mood or behaviour changes during their heat cycle. She might become more clingy, following you from room to room or wanting extra attention. Others may seem restless, pacing, whining a little, or acting like they can’t quite settle.
Another common behaviour is “flagging”—when she lifts her tail to the side or sticks her bottom out, especially when touched near her back. This means she’s becoming more receptive to mating.
Not all dogs act the same, so it’s okay if your girl seems different from others you’ve known. Just keep things calm at home, stick to their routine as much as possible. If you're currently doing any behavioural training, it’s best to keep things light and familiar. The ability to focus may be affected during a female dog’s period cycle, and it helps to avoid introducing anything too new or demanding during this time.
What to Do When Your Dog Is in Heat
When your dog is in heat, the most important thing to do is keep her safe, comfortable, and away from male dogs. This stage of the female dog period cycle can feel like a lot, especially if it’s your first time dealing with it—but with a few simple steps, you can help her through it with confidence.
Home Care Tips
Hygiene Solutions
One of the first things you’ll notice is the discharge. To manage this, many owners use dog nappies or heat pants. These help keep your home clean and reduce how often you need to wash bedding or mop the floor.
Make sure she has a clean, cosy space to rest—like a soft bed in a quiet room where she can relax. If you live in a flat or smaller space, washable blankets or puppy pads can really help during this time.
Avoiding male dogs
It’s very important to keep your dog away from male dogs while she’s in heat—even if they’re just neighbourhood pets or playmates. Pheromones in this stage can attract male dogs from far away, and they can become very determined.
Keeping her calm and comfortable
Some dogs feel out of sorts when they’re in heat. They may be clingy, anxious, or restless.
You can help by keeping a calm routine, offering extra cuddles if she wants them, and giving her quiet time when she needs it.
If you live in a busy home, consider creating a safe corner where she won’t be disturbed—somewhere she can feel safe, especially if she’s feeling overwhelmed.
Tracking Your Dog’s Cycle Helps You Make Better Health Decisions
Getting to know your dog’s heat cycle might seem like just one more thing on a long to-do list—but it really does make a difference. By keeping track of her signs and knowing what stage she’s in, you can make better choices for her health, comfort, and safety.
If you’re thinking about breeding, speak to your vet first. They can guide you through the process, check that your dog is ready, and help you plan things the right way. But even if you’re not planning to breed, your vet can still help you decide the best care options and timing for spaying.
You don’t have to figure this all out on your own. If you’re unsure about what your dog is going through, or just want to be better prepared for her next cycle, have a quick chat with your vet. We’re there to support both of you—and your dog will feel all the love and care you're giving her every step of the way.
Frequently Asked Questions
1. Do female dogs stop having heat cycles when they get older?
No, female dogs do not go through menopause like humans. They continue to have heat cycles throughout their lives, though the cycles may become less regular as they age.
2. Can you spay a dog while she’s in heat?
Yes, but most vets recommend waiting until her cycle ends. Spaying during heat can carry a higher risk of bleeding, so many prefer to wait about two months after the cycle.
3. How long does a female dog usually bleed for?
Most dogs bleed for around 7 to 10 days during the first stage of the cycle. The amount can vary—some bleed more, others less.
4. How do you take care of a female dog on her period?
Keep her clean with dog nappies or washable bedding, and give her a quiet, comfy space to rest. Avoid walks near male dogs and try to stick to her normal routine to keep her calm.
5. What should you avoid when your dog is in heat?
Don’t let her off-lead outdoors or near unneutered male dogs. Avoid dog parks and keep male dogs in the home separated to prevent unwanted mating.
