How Long Do Chihuahuas Stay In Heat?

Chihuahuas, like other small breed dogs, typically go into heat every six months, with each heat cycle lasting approximately 2 to 4 weeks. The first cycle usually happens when the dog is between six months to one year old.

During this time, you’ll notice behavioral changes and physical signs like a swollen vulva, bloody or straw-colored discharge from the vulva, and increased urination. It’s important for owners to properly care for their pets during this period, as it can be a stressful time for them.

The heat cycle is a natural part of a dog’s reproductive cycle and also the time when she can become pregnant. Unless you plan to breed your dog, it’s usually recommended to spay her to avoid unwanted pregnancies and to enhance her health and lifespan.

Last Updated on September 20, 2023

There is no wonder why Chihuahuas are one of the best dogs to have. You can carry them everywhere, dress them in the cutest costumes, and prefer your lap more than any expensive dog bed you bought. If you just got one, congratulations! Best decision ever!

But if you’re reading this, I take you to have some questions about her heat cycle. Keep reading to learn how you can make this sensitive time easier for you and your Chi. Or you can just jump right unto your inquiry through our table of contents.


If you own a female chihuahua, then you will experience having to deal with her in heat. You will notice her mood changing and her behavior becoming unusual. She may even show aggression, even when she didn’t before. Your best weapon? Knowledge. Learning what to expect when she is in heat and preparing accordingly can come a long way.

What does it mean when your dog is in heat?

When your Chihuahua is in heat, it means she is fertile. If she hasn’t been spayed and you let her near unneutered dogs, she can get pregnant. During her heat cycle, there’s an increase in her estrogen levels, and then decreases, and then her ovaries release eggs for a possible mating. This is the only time she can get pregnant. So, if you have plans on breeding her, letting her mate during her Estrus stage (more on the stages of heat cycle later) will possibly result in puppies.

Or if you’re not planning to breed her just yet, keeping her away from unfixed dogs during her heat cycle will be best. For further reading head on to, Can A Dog Get Pregnant When Not in Heat?

When should I expect my Chihuahua to get her first cycle?

Unlike large breeds, Chihuahuas get their first heat at an earlier age. Most Chihuahuas will get their first heat cycle by the age of 6 months- 1 year old. However, if your dog doesn’t get her first cycle at this age, that’s okay too. It’s important to remember that each dog is different. Some female Chihuahuas take over a year before they get their first cycle. It’s not unheard of that a Chihuahua experience her first heat at the age of 2.

But for your Chihuahua’s sake and your peace of mind, talk to your veterinarian. See if there’s an underlying problem. If he gives you the clear all, she may just be a late bloomer. Or she’s already had her first heat, but you didn’t notice. If you did, that’s okay.

This is pretty common as Chihuahuas are clean-freaks, and there’s a possibility that she cleaned off any proof of being in heat. Also, she may be experiencing what is called a split heat. It’s a common occurrence for small breeds, especially during their first heat. The symptoms of this type of heat are very subtle, hence are very easy to miss. Again, not unheard of. To add, if you plan to breed your dog at an early age, the AKC recommends you wait at least until her third heat, about 18-24 months.

Chihuahua on arm

What are the signs that my Chihuahua is having her heat?

There are 4 stages your dog goes through when she is in heat. Depending on the signs you see, it tells you what stage she is in her cycle. Below is an in-depth look at each phase, its symptoms, and what you can expect for each one of them. Let’s get to it, shall we?


This is the first stage of the heat cycle. On average, the proestrus stage lasts for about 9 days. Her estrogen level will rise, and her follicles (eggs) will begin to develop. One of the prominent signs during this stage is a bloody vaginal discharge. However, as previously mentioned, you will most likely miss this, especially if you own an overly neat Chihuahua. Other symptoms also include the following:

  • Swollen nipples and vulva
  • Excessive licking at her genital area
  • Clingy behavior to their owners
  • Tail tucking
  • A general shift in her mood

Apart from those mentioned above, you may also notice other male dogs becoming more interested in her. Males will attempt to mount her, but she won’t be receptive to their attention at this time. Thus, she will tuck her tail, or sit every time another dog approaches. On the other hand, some female Chihuahuas will be more playful and chase males around.


The second stage of your dog’s heat cycle is the estrus stage. This stage is considered the fertile window in your dog’s reproductive cycle and lasts between 4-13 days. Her discharge is now in the shade of pink or straw-colored, and your Chihuahua will constantly be in a “standing heat” position. This means she will stand still with her tail pulled to the side, a sign that she’s welcoming males.

Additionally, males will be even more attracted to her during this period. If you don’t have any plans of breeding her, keep her away from male dogs. Do not let her outside unsupervised. Trust me, males will jump fences and even dig under them to get to her.


As long as your dog hasn’t been impregnated, she will enter the Diestrus stage. This stage is considered the resting period of your Chihuahua and allowing her body to recuperate. Her vulva will return to its normal size, and any signs of discharge will cease. She won’t be interested in male dogs as well. This stage will last for 30-90 days.

Chihuahua with dog clothes

To add, some dogs will experience a false pregnancy at this time. She will exhibit signs such as restlessness, lethargy, nesting (digging bedding or moving it around), nursing (increased attachment to her favorite toy), loss of appetite, and aggression. Other times physical evidence like enlarged mammary glands can also be observed. If it’s a false pregnancy, the symptoms will go away after a month or two. But if you suspect her to be pregnant, take her to the vet immediately. Chihuahuas are more inclined to have a risky pregnancy because of their relatively small size. Taking them to get checked by the vet is a wise decision.


The anestrus stage or your dog’s “default” state is the final phase of the heat cycle. It lasts for about 2-6 months before another cycle begins. Hence, your Chihuahua will most likely get her heat once in 5-8 months, or roughly twice a year. Beware though, as this is not the time to relax just yet. Intact female dogs are in danger of getting an illness called pyometra.

According to the AKC, pyometra is usually seen in dogs aged over 6 years, but it can happen to dogs of any age, even during their first heat. There are two kinds of pyometra: open pyometra and closed pyometra. Signs of closed pyometra are low energy, excessive thirst and urination, vomiting, and a bloated stomach. For open pyometra, a thick vaginal discharge can be observed. If you see any of these signs, treat it as an emergency.

Tips on how to deal with your Chihuahua in heat

  • Track her heat cycles. When you track your Chihuahua’s heat cycle, you can better prepare for the next few weeks that she’s in heat. Whether you’re planning to breed her or not, understanding her heat cycle will help you.
  • If you don’t have any plans to breed her just yet, keep her away from male dogs. If you want to take her for her daily exercise, make sure you put her on a leash. Even if she is good with walking without one, her instinct to mate will be stronger.
  • Keep her in a secluded area. If you don’t want to breed her yet, keeping her in a safe place where other dogs can’t get to her will do the trick. As previously mentioned, male dogs will do everything they can to get to her. If you have a fenced backyard, reinforcing your fences might be a good idea. Or better yet, keep her away from the backyard. The call of nature is hard to ignore, especially for male dogs around a female dog in heat.
  • Stock up on her favorite food. As you might have known by now, she will go through some changes during her heat cycle. And this includes her appetite. She might refuse to eat her usual dog food, so you need to find another way to make her eat. The solution? Keep other types of dog food she likes. She might appreciate the change of texture wet dog foods or dehydrated dog food brings.
  • Consider spaying her. There is nothing wrong with not spaying your dog. But if you’d rather not worry about unplanned litters and don’t have plans of breeding her in the future, spaying might be a good idea. Ask your veterinarian about the risks and benefits of having your dog spayed.Chihuahua

Also related: What To Expect After Your Dog Is Spayed or Neutered


A dog’s heat is natural, but it doesn’t mean it’s easy. This is especially true for pet parents who own a small breed like Chihuahuas. Your Chihuahua will most likely get her heat once every 5 months, or roughly twice a year, lasting for 2-4 weeks. During this time, you can expect her mood, appetite, and behavior to change. Be sure you follow the tips mentioned above to make this sensitive time trouble-free for you and your dog. Also related: How Do You Know When Your Dog Is In Heat?

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