Dogs In Heat: A Complete Guide
Being a sane human and caring parent, you need to be responsible for your dog and its care. Female dogs are in heat when they have entered the fertility part of their reproductive cycle.
There comes a time in the life of an intact female dog when they are ready to breed. This is the period we call being in heat.
Table of Contents
In this article, I will guide you from step to step and clear all your concerns regarding your dog is in heat. First of all, let’s dive into basic information on dogs in heat.

Take Dive Into Basic On Dogs In Heat Information

When Does Dog Heat Start?
It varies from breed to breed and according to their size. On average, a dog’s first heat begins at around six months of age. Smaller dogs can go into heat once they are 4 to 6 months old. At the same time, medium and large dog breeds take 18 to 24 months on average to go into heat.
Even though you may think your female dog is old enough to get pregnant, in reality, dogs eggs don’t fully mature until another 6 to 18 months. To know what influences their heat cycle, you will have to learn about the four stages of a dog in heat.
Let’s know about the dog heat cycle and its four stages.
What Are The 4 Stages Of A Dog In Heat?

The dog heat cycle has four different stages. Proestrus, Estrus, Diestrus, & Anestrus are the stages when a dog goes through many physical, behaviour, hormonal, cytologic, and physiologic changes. Your canine is likely to show differing signs at each location.
Here, we will learn about the different signs related to clinical behaviour, hormonal, vaginal smear, and physiologic changes.
Your canine will exhibit and expose several notions at each stage to let you know what they are going through.
Learn The 4 Stages Of The Dog Heat Cycle
Proestrus Stage.
This is the first stage of a canine oestrous cycle. The proestrus stage usually lasts from 3-17 days. On average, many dogs’ proestrus stage lasts nine days.
The very first sign of your dog being in this stage is its vulva swelling. If I were at your place, I would have considered looking for this sign as it is the best way to spot any dog’s heat cycle beginning.
Signs Of Dog In Proestrus Stage.
- Female dog becoming more clingy with her owner.
- A female dog may seem a bit grumpy in its proestrus stage.
- Change in appetite. Your canine may get hungrier or go off her food a bit in the first week of their proestrus stage.
- Vulvar swelling. The degree & bleeding of swelling can vary from dog to dog as some dogs swell just a little while others swell quite a lot.
- A dog will keep tucking its tail in its proestrus stage. In response to vulvar swelling and to guard it, they prefer taking their tails by sitting down or between the legs whenever any being approaches.
Estrus Stage
This is the second stage of a dog reproductive cycle which lasts from 3-21 days. In this stage, the dog will be fertile, meaning in her actual heat when the ovaries start releasing eggs for further fertilization.
This is the stage when you will notice a female dog willing to be around male canines. This is the stage when a female pup accepts male company. During this period, you will see your dog wanting to be outside more often than she used to.
There is no fault of hers as it’s her instinct to breed. Let’s learn about the symptoms that tell your dog is in the second stage.
Signs Of Dog In Estrus Stage.
- A female dog discharge lightens. You might have noticed your dog discharge being bright red previously. Now, in this stage, it will lighten up to be somewhat pink.
- Now, her vulvar swelling should have subsided. It usually happens to make the vulva soften enough for penetration.
- Instead of pushing away male company, a female canine will start behaving flirtatiously.
- She is roaming a lot around male dogs.
- She is holding her tail high and out of the way.
Diestrus Stage
A dog’s Diestrus stage will last from 60-90 days until she is no longer fertile. This is the stage when the canine’s fertility part of its heat cycle comes to an end.
The most exciting thing about this stage is if the dog has been impregnated, this stage will end until the birth of the puppies.
Signs Of Dog In Diestrus Stage.
- Canine avoiding to mate.
- She will no longer be interested in flirting for having male company.
- 90% of the vulva swelling is gone. Their vulva may seem slightly enlarged, which is ordinary and not concerning at all.
Anestrus Stage
Being the final stage of a canine heat cycle, it is also popularly known as the resting stage. The Anestrus stage will last from 100-150 days, being the most extended phase.
This phase will end when her entire heat cycle starts again. There is no sign or symptom to look at as there is no need. Let’s know further about the dog heat cycle.
How Long Is Each Cycle Last?
Canine’s Heat Cycle Stages | How Long Each Dog’s Heat Cycle Lasts |
Proestrus Stage | 3-17 Days |
Estrus Stage | 3-21 Days |
Diestrus Stage | 60-90 Days |
Anestrus Stage | 100-150 Days |
Is This A Lifetime Thing?
Yes. After their heat cycle, a female dog will experience Estrus throughout their lives. In the case of medium and large-sized dogs, they are likely to experience a heat cycle once a year, whereas smaller dogs may go into heat 3-4 four times a year.
Firstly, the dog’s heat cycle will be irregular. It varies from dog to dog. Some dogs can take up to 18 months or more until their cycle becomes regular.
Mang owners face issues when their pet female dogs dive into heat cycles. This is why you might have noticed many canine owners electing to spay their female pooch.
If you are not looking to get your dog breed, I will advise you to get your dog spayed before the first heat because it reduces the risk of mammary cancer and other health issues.
What Is A Female Dog In Heat Called?
The whole process of a female dog going into heat is called the Estrus cycle. As I told you earlier, each cycle will have four stages. If the female dog is impregnated, she will skip the 4th cycle.
The 3rd stage will last until the next heat cycle starts again. On the other hand, if a female dog has passed the 2nd stage without being impregnated, she will have to face four steps.
A dog is only said to be in season or heat when its estrus stage begins. From here, we are going to learn what to do when your dog is in heat. After that, we will look at the dog heat cycle chart and learn about the dog’s Estrus cycle.
What To Do When Your Dog Is In Heat?
Here are the following things you should do when your dog is in heat.
1.) Never let your canine off-leash when she is in heat.
You are fooling yourself by underestimating your female hormones and intent. Even a dog with excellent obedience skills may fall to the wayside when intimidated or influenced by her hormones in the heat cycle. In this period, she will look for the male puppy to satisfy her instinct to breed.
2.) Keep their diet unchanged and consult a veterinarian.
You should visit your nearest veterinarian’s office with your canine to get her checked once a month. This is important when she is in her 1st and 2nd stage of the heat cycle.
3.) Get her spayed after the heat cycle is over.
If you have no intention to breed your canine, consider waiting for her heat cycle to end and get her spayed. The best time to spay a dog is before its first heat cycle to prevent any illness. However, your veterinarian will guide you on the appropriate stage and age to spay your dog.
4.) Never allow your dog out in the yard alone.
This is something that most dog owners make mistakes in. When a dog is in its heat cycle, it will likely look for an opposite-gender companion. Plus, leaving your dog out in the yard can drive male dogs to find females emitting breeding pheromones.
5.) Keep the dog on a GPS tracking collar.
It is essential to keep them on a trackable collar. In the heat cycle, most pet dogs are prone to escape. If anything unthinkable happens, you will still be able to relocate your dog. If your dog escapes or runs off from your yard, make sure to have the updated ID tag, the GPS tracking collar (I like Fi Smart Dog Collar), and the current microchipped contact info.
Fi Smart dog collar relieved my anxiety and fear of losing my dog. I reside in a town where dog theft happens. My dogs are very comfortable with this with the Live GPS tracking Collar feature.
It will also allow you to monitor the physical activity, location, and movement of your dog. I like it because it prevents dog theft as well. I have been on a search for the most effective dog collar with minimal design & features. This one so far I found to be the best. Let dive into a 3-min read on FI Smart Dog Collar Review to find out more.
Dog Heat Cycle Chart
Recognizing Dog In Heat

How To Tell A Dog In Heat?
Here, I am going to tell you how to recognize a dog in heat. Whether your dog is going into heat or in heat, these are the signs that you’re likely to notice. Sometimes, the few symptoms mentioned below are caused due to health issues or illness as well.
For example, decreased appetite & vaginal discharges are common signs of both heat cycle and life-threatening Pyometra. Occasionally, female dogs tend to experience health issues after their heat cycle.
If any of the signs mentioned below continue after her heat cycle end, get her checked. Most of the symptoms below should be gone in the 3rd stage of their heat cycle.
When a female dog’s uterine lining remains thick, its system produces more fluid which is great for bacterial growth. This can lead your female dog to uterine infection or a life-threatening Pyometra. Here are the signs of female dogs suffering from Pyometra after her heat cycle.
Pyometra Symptoms In Dogs
1. Appearing lethargic
2. Decreased Appetite
3. Increased Thrust
4. Vaginal Discharge
5. Fever or Feeling Unwell
6. Frequent Urination
7. Vomiting
Note: Pyometra is a severe condition for dogs, so I highly recommend you always visit the Vet for periodic testing. Visit the nearest Veterinarian office once a month with your dog when they are in the first or second stage of their heat cycle.
What Are The Signs Your Dog Is Going Into Heat?
Here are all 11 signs that your dog will exhibit if they are going into heat.

1. Urinating Frequently.
2. Looking For Or Opposite Sex Company.
3. Scratching All Licking Their Genitals excessively.
4. Male Dogs May Seem Over-Excited, Aggressive, or Nervous Depending Upon Each Personality.
5. Female Dog Vulva Will Be Large, Red & Swollen.
6. Male Dog Keeping Its State As High As Possible.
7. Female Canine Will Guard Her Vulva Using Her Tail.
8. Licking The Back End More Than Usual.
9. Being Overly Friendly To Other Dogs.
10. Yellow, Red, Brown Discharge.
11. Humping
What Are The Symptoms Of A Female Dog In Heat?
Below are the signs a dog will exhibit if they are in the heat.
- Bloody or light pink discharge from the vulva.
It usually starts at the first stage of her heat cycle. As soon as she enters the 2nd stage, their discharge lightens up to pinkish.
2. Swollen vulva.
The swollen vulva will be visible when a dog is in heat. It will soften in the 2nd stage for proper penetration but will appear enlarged in size.
3. Dog licking their genital area excessively.
This is something we have noticed more frequently. Dogs usually lick their genital areas, but they are in heat, or their mating season is arriving if they are excessive.
4. A dog is exhibiting aggressive, nervous, or agitated behavior.
A change in their behavior will be noticed soon. A dog in heat may seem aggressive or nervous. When looking to mate in the season, male dogs tend to be bold, whereas females become shy and flirtatious.
5. I am respective to the opposite sex.
Dog in heat will always look for the opposite sex in response to the instinct to breed. You should keep your canine escape-proof.
6. Change in tail position.
You will notice a dog keeping its tail high in the heat cycle.
7. I am urinating more frequently.
Along with discharge, the dog will also start urinating more frequently. The frequency of urination should decrease after the end of the second stage.
What Happens When A Dog Is In Heat?
Female Dogs: When female dogs are in heat, they usually go through lots of changes. In the heat, female dogs need to be kept distracted or entertained. They typically suffer from anxiety and face discomfort during the heat cycle. In the heat, females will release a specific scent that arouses male dogs.
They will attract male dogs, but consider keeping them far from the non neutered dogs if you want to avoid breeding your dog. A female dog in heat will also pee a lot. They will also have different color discharges. No one can say a dog’s need while in heat because it may vary from personality to personality. A canine in heat feels uncomfortable and fidgety. If you see your dog having pain or discomfort, consult your Vet.
Male Dogs: Male dogs don’t go in heat or any Estrus stage/period. The male dogs of every specific breed are capable of mating all year round once they are fertile.
Although they don’t go in heat, they still feel like tracking down the female dog in heat. If an intact male dog catches the scent of a nearby female in heat, he will become obsessed to shift his entire focus on her.
In the heat, female dogs tend to release a pheromone called methyl p hydroxybenzoate which sexually arouses male dogs. You will notice male dogs having decreased appetite and increased their marking. At that moment, males can become increasingly aggressive. If you are not looking to breed with your dog, consider keeping an intact male dog far from an entire female dog in heat.
How Long Heat Lasts?

How Long Does A Female Dog Stay In Heat?
A female canine heat cycle usually lasts 14-28 days. At the beginning of the heat cycle, the female dogs will not be receptive to two males. Maybe this is because of her swollen vulva.
Dogs with a swollen vulva will be receptive to males after the first stage of its heat cycle when it softens up for convenient penetration. At the same time, some females tend to be receptive throughout the entire process.
When a female dog’s vulva returns to its normal state, size, and color without any bleeding or discharge, her heat cycle is over. In the first heat cycle, your female dog will go through a lot because she has to face many physical, behavioral, hormonal, and other changes one by one rapidly.
A second heat cycle may not be regular due to stress, but after 18-24 months, your dog will have a proper heat cycle without any irregularities.
How Long Does A Dog Stay In Heat After Bleeding Stops?
After bleeding stops, a dog will stay in heat for 7-10 days more. Every female dog is different, and it can vary from one dog to another. If the bleeding has stopped, the vulva is not swollen much, and the female dog doesn’t seem receptive, she will no longer stay in heat, and her heat cycle will only last for another 3-4 days.
How Many Days Does A Female Dog Stay In Heat?
14-28 Days.
How Long Does A Dog Stay In Heat After Mating?
After mating, a female canine will stay in heat for another 7-10 days or less. Each dog has different body mechanisms and will vary from puppy to pup. Estrous is the period when a female dog should be impregnated / Mate.
How Long Does A Dog Stay In Heat After Being Spayed?
Canines that have been spayed should not have a regular heat cycle. It’s never recommended to spay your dog when she’s in heat. Puppies with functioning ovarian tissue or tiny pin-sized pieces of ovary left behind during spay surgery can make your dog have regular heat cycles.
The best time to spay your dog is after 2-3 months when the heat cycle is over. If you have fixed your dog but are still in heat, get her checked with the veterinarian.
How Long Does A Dog Stay In Heat The Second Time?
The second time, a female dog can stay in heat for 7-21 days. Irregularities in younger dogs’ heat cycle are typical when it’s for the second time. The stress level of the first heat cycle experience can make your dog stay in heat for more or less than 7-21 days. The past experiences of the heat cycle the first time can make a dog anxious and stressed.
Dog Bleeding In Heat

How Long Does A Dog Bleed When In Heat?
In the heat cycle, dogs can bleed for around 7-10 days. During the first proestrus stage of the Estrous process, female canines will keep their distance from males and will not be receptive towards the opposite sex.
During the Estrous period, some female dogs experience heavy bleeding while others with minimal bleeding. At the first stage, when they bleed, you will notice them being attracted towards male dogs but not being receptive or allowing them to mate. Once they stop bleeding and their vulva become soft, they are ready to mate.
How Long Does A Dog Bleed In First Heat?
The dog in the first heat will bleed for around half of her total Estrous cycle. A female dog is likely to bleed for around 7-10 days in her first heat cycle. She can make a bloody mess in her first heat, but instead of scolding her, try reassuring her with a calm mind while you clean it up.
Feeding her proper nutrients and ensuring she drinks plenty of water will help her feel relief more often. Nutrient deficiency during her Estrous cycle will result in severe health issues.
How Long After Bleeding Is A Dog Fertile?
If a female dog’s bleeding stops after 7-10 days, she will be fertile for another 7-14 days. In the Estrus period, the second stage of a heat cycle, the dog will be productive. In this stage, their ovaries release eggs for fertilization.
During the heat cycle, the bleeding becomes more watery or ultimately indicates your dog’s peak fertility. This stage allows females to be receptive towards male dogs, and it can last as long as 20 days in some dogs.
How Long Does A Female Dog Bleed For?
As said earlier, female dogs bleed for around 8-11 days in their proestrus period. In the second stage, they become fertile for mating and breeding. At the same time, male dogs don’t have heat cycles or bleeding.
Frequently Asked Questions
How Long Is A Female Dog On Her Period?
Female dog’s period tends to last 7-14 days. During this period, her vulva will be swollen, enlarged and red with some bleeding. This usually takes place during her heat cycle. Some female dogs’ periods can last shorter or longer than this depending upon their body functions.
How Often Can A Dog Get Pregnant?
Small-sized dog breed usually comes in heat twice or thrice a year to get pregnant the same number of times. Medium-sized dog breed can get pregnant twice a year, whereas wild giant breed once every 12-18 months.
When Can A Dog Get Pregnant After Bleeding?
After bleeding, in an Estrus stage, when her eggs are ready for fertilization, she can get pregnant. When the female dogs are at their peak fertility (around the 2nd to 3rd week), they should mate and breed.
When Is The Best Time To Breed A Dog In Her Heat Cycle?
When the female dog is at its peak fertility, it is best for breeding. Female dogs tend to be at their peak fertility between the 10th and 14th day of the estrus stage. Make sure to have the blood tests, and all the preparation is already done to determine the best period for your dog to breed.
When Should I Allow My Dog To Breed?
In the first stage of her heat cycle, you can allow your dog to breed, but only if you’ve planned, learned, and done everything that needs for breeding.
How Much Blood Is Normal For A Dog In Heat?
A female dog can bleed either heavily or very little in a heat coma as it varies between dogs. The amount of blood doesn’t matter as long as your dog only bleeds for around half 7-10 days. Super large dog breed can bleed for up to 14 days as well.
How to tell if a dog in heat is pregnant?
Usually, a dog in heat that has been impregnated can only be detected by visiting your Vet. A female dog will start showing signs after three weeks into the pregnancy. Nesting behavior, decreased activity, enlarged nipples are some of the characters to watch for.