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Chihuahua Heat Cycle: 9 Burning Questions Answered + 4 Tips

Chihuahua Heat Cycle

Wondering how long your Chihuahua stays in heat?

Or having other questions about your Chihuahua’s heat cycle?

Here you’ll discover the answers to the most frequently asked questions.

Keep reading to discover:

  • What it means when your Chihuahua goes in heat.
  • The 4 stages of your Chihuahua’s heat cycle (and how you can recognize each stage).
  • Simple and important tips for when your Chihuahua is in heat (#3 is a little bit weird but very important).
  • And more…

Chihuahua Heat Cycle

A Chihuahua’s heat cycle is her most fertile period. Her body shows physical signs when her ovaries release an egg. This means she’s able to get pregnant. If she doesn’t conceive, her uterus will shed its lining.

That being said, below I’ll answer…

The 9 most asked questions about the Chihuahua Heath Cycle

#1: What does it mean when a Chihuahua goes in heat?

Like most mammals, your female dog has periods when she’s fertile and less fertile.

Her heat is the period in which she’s fertile, and involves four stages that we’ll get into later.

Her hormone levels go up, then down when her ovaries release eggs for potential fertilization. 

Your Chihuahua will only go into heat if she hasn’t been spayed (‘fixed’). This means she can also get pregnant if exposed to intact (or not ‘fixed’) males. 

But, this is also the only time when she can get pregnant, so you can have her around intact males when she’s not in heat.

#2: How long do Chihuahuas stay in heat?

Your Chihuahua’s heat lasts about three weeks on average. This is in the middle of the two to four-week-long heats that other dog breeds have. That might feel like a long time, especially when you think about a dog’s overall life span.

But: It’s not so bad if you think about how often they go into heat.

Also, the dog doesn’t have the more visible or severe symptoms throughout that whole time, easing her discomfort.

#3: How often does a Chihuahua go into heat? 

Chihuahuas go into heat every five to eight months on average, though it varies from dog to dog. This generally means they have one twice a year. Going back to the heat length, that means they only spend about six weeks out of the year going through this process.

However, the spacing of them isn’t always exact. For instance, you can’t always count on your dog’s heats in February and September every year.

When a dog starts going into heat, her cycles might not be typical in their spacing and symptoms. But, this evens out over time.

Once your dog’s heats become more regular, you’ll sense your dog’s unique pattern.

She’ll have her heat cycles throughout her entire life. There’s no menopause for dogs, though the risks of pregnancy are higher if she’s a senior dog. 

Her chances of conceiving are also much lower the older she gets, so if you’d like to breed your dog, do it when she’s in the prime of her life.

#4: How can you see when a Chihuahua is in heat? 

Signs That Your Chihuahua Is In Heat

For many larger dog breeds, it’s easy to see when they’re in heat – they’re just bigger, and it’s easier to see their bodies change.

But, Chihuahuas are a little different. They’re small and naturally very tidy. They can clean away the typical signs of their heat by grooming themselves. You might miss the signs.

You need to pay close attention to see if they’re in heat, especially at first. But it’s not impossible to see, even if your individual dog’s signs are subtle. 

What will her heat symptoms be?

You can tell your Chihuahua is in heat by looking for the following signs:

  • Swollen vulva.
  • Behavioral changes.
  • More frequent urinating.
  • Increase or decrease in appetite.
  • Slightly bloody vaginal discharge.
  • Increased interest from male dogs.
  • Tail flagging (holding their tails to the side to allow males to mount).

These symptoms appear at various times in her cycle (or not at all, sometimes), so knowing your dog’s personality is key to understanding her heat.

If your dog is usually super sweet, but suddenly gets aggressive, she might be in heat. Or, she might lose her appetite when she goes into heat. Every dog is a little different.

But what if you still can’t tell?

Remember when we discussed how tidy Chihuahuas are? If your dog seems to be grooming her privates more, that could be a sign too. There are also variations in heat that we’ll discuss later.

#5: What are the stages of a Chihuahua’s heat cycle?

Heats for dogs, Chihuahuas included, are broken up into four stages – three active stages and one relatively inactive stage. These stages are:

  • Proestrus.
  • Estrus.
  • Diestrus.
  • Anestrus.

What goes on in each stage?


This is the first stage of heat and lasts between five and eight days. Her estrogen levels are highest in this stage, and her body is preparing for a possible pregnancy.

‘Preparing’ is the key. Her body won’t be ready to conceive yet. 

Male dogs will definitely be more interested in her at this point, sniffing her, attempting to mount her, and generally trying to be around her. But even though her heat has started, she’ll reject all male attention at this point.

Male dogs can smell a female in heat from up to three miles away! As we get into this, it’s really important to mention that you should shield her from male dogs at this time.

Signs of proestrus include:

  • Swollen vulva.
  • Swollen nipples.
  • Increased attention from male dogs.
  • Some reddish discharge, but not a lot.
  • Tail tucking (covering her vulva with her tail when males approach).


This second stage of your Chihuahua’s heat cycle, also called ‘standing heat’ is when your dog is ready to mate. 

Progesterone rises while estrogen falls, allowing her ovaries to officially release an egg. She’ll release multiple eggs over 24 hours. 

This is the only time when mating will be successful – she’s at her peak fertility about two days after she ovulates, though she can get pregnant at any point in this stage. 

If you allow her to come into contact with intact male dogs, she’ll probably mate with them.

Or, if you’re artificially inseminating your dog, this is when you’d start that process. The American Kennel Club has more info on that here.

Signs include:

  • Swollen vulva.
  • Red to pink discharge.
  • Continued behavior changes.
  • Actively seeking out male dogs.
  • Tail flagging (lifting her tail when males approach).


This stage is also known as metestrus, and your Chihuahua’s hormones finally level out. Regardless of whether your dog conceives, this is the end of the active part of her heat. 

She’ll also probably lose interest in male dogs – his job is done, or she’s not interested in mating anymore. Any attempts at mating wouldn’t result in pregnancy at this stage.

This is when you’d find out she’s pregnant if she was artificially inseminated or mated naturally. Chihuahua pregnancies typically last 63 days, the duration of the rest of this cycle.

Here’s a video on detecting whether your dog is expecting or not (before you check-in with your vet, of course!):

If she isn’t pregnant, this phase lasts about two to three months. In this stage:

  • Vaginal discharge stops.
  • Her vulva returns to its normal size.
  • She loses significant interest in male dogs.

But what if she’s still acting ‘off’ despite being out of heat? Why hasn’t she gone back to her normal self? What if she still has swollen nipples after heat?

She might be experiencing what’s called a ‘false pregnancy.’

What is that, and how is that possible? 

Basically, her brain is tricking her body into thinking she’s pregnant. Her chances of it go up if there are other dogs in the house, particularly male ones.

It’s thought to be caused by a hormonal imbalance between progesterone and prolactin. However, veterinarians aren’t sure of the exact cause of the condition.

According to PetMD, your dog might be experiencing a false pregnancy if you see the following:

  • Vomiting.
  • Restlessness.
  • Loss of appetite.
  • Abdominal distention.
  • Nesting behavior (like ‘mothering’ her stuffed animals).
  • Brownish, watery secretions from enlarged mammary glands.

Thankfully, these symptoms usually go away after a month or two. Check-in with your vet if her symptoms become severe.


This is your dog’s ‘default’ – everything from her behavior to her anatomy should return to normal.

Even though there aren’t any visible signs of heat, your dog’s reproductive organs and hormones are gearing up for her next cycle.

Anestrus lasts about two to six months before it starts all over again with proestrus.

But, even though your dog isn’t in heat, you still have to be vigilant about behavior changes.

Intact female dogs can suffer from a fatal illness called pyometra. According to the AKC, this typically happens in dogs over the age of six, but it can happen at any time.

It occurs within twelve weeks after a heat cycle. Hormone exposure creates cysts in a dog’s uterus that leak and breed bacteria. 

These bacteria-filled fluids build and can’t be expelled. This causes severe illness.

There are two kinds – open pyometra and closed pyometra.

Symptoms of open pyometra (pyometra where accumulated fluids can leak out through the cervix):

  • Foul-smelling, thick discharge.
  • Minimal other behavioral changes, at least at first.

Symptoms of closed pyometra (pyometra where accumulated fluid can’t escape the womb):

  • Vomiting.
  • Low energy.
  • Stomach bloating.
  • Increased drinking and urinating.

Take your dog to the vet immediately if you suspect she has pyometra. A dog’s health can spiral down quickly with this disease.

Your vet will likely remove her infected uterus and ovaries to save her life.

#6: How old is my Chihuahua when she has her first heat?

Old Chihuahua Meme

Your Chihuahua’s first heat will usually happen when she’s between six and eight months old. As with most things, some dogs start earlier, and some start later.

If your Chihuahua hasn’t started her heat by the time she’s eighteen months old, check in with your vet. She could have a birth defect, or she might just be a little behind.

No matter when her first heat happens, don’t breed her during her first one. Her body hasn’t adjusted to the hormonal changes yet. 

You could put her life at serious risk.

Also, her body will likely be too small still. Even adult Chihuahuas have a difficult time giving birth because of their size.

#7: What to do when a Chihuahua is in heat? 

Whether you breed her or not, you’ll have to take special care of your Chihuahua during her heat.

Not caring for your Chihuahua while she’s in heat can have major consequences for both of you. 

Here’s the deal: 

If she gets pregnant, you’ll have a litter of puppies on your hands. If you’re a breeder, that’s great, but if you aren’t, there’s a steep learning curve involved.

You’ll need to make sure all the puppies get veterinary care. This can be extremely expensive.

You’ll need to make sure they all have space to play.

Most importantly, you’ll likely find them good, loving homes once they’re weaned (unless you want up to six new puppies at home.)

Plus, the pregnancy could be difficult on her tiny body, as briefly mentioned before. 

Small dog breeds tend to have complicated deliveries because of the size of the mother in relation to the size of the puppy…

Often, they need C-sections to give birth safely. Sometimes other complications lead to the death of the mother, the puppies, or both. 

But obviously, someone breeds Chihuahuas – how else would they be so common and popular?

Who should breed Chihuahuas? 

People who breed Chihuahuas should have experience or extensive knowledge of breeding them, along with access to emergency veterinary care and the costs associated with it. 

The AKC has a great guide on responsible dog breeding here. 

Long story short: don’t rush into breeding – it’s a serious activity that should never be taken lightly.

What do you do if your Chihuahua is in heat, and you don’t want to breed her?

  • Keep her calm.
  • Keep her clean.
  • Manage her pain.
  • Cover her bottom.
  • Keep yourself calm.
  • Buy the proper gear.
  • Give her more attention.
  • Handle her more carefully.
  • Adjust to her mood swings.
  • Keep an eye on her appetite.
  • Protect your home from other dogs.
  • Keep her inside as much as possible.
  • Let your Chihuahua rest more than usual.
  • Keep her on a leash at all times when you do take her outside.
  • Be prepared for what could happen, even if it’s unlikely (like having a split heat).

You might be overwhelmed to look at all of this. How can you manage all of that for nearly a month? But don’t worry – it’s easier than you think.

We’ll get into more specific tips on dealing with your Chihuahua’s heat later in the article.

#8: My Chihuahua is in heat, but isn’t bleeding. What now?

Your female Chihuahua is suddenly attracting male dogs left and right, but she’s not bleeding. Why? There are two likely culprits for this.

The first is a ‘split heat,’ and the second is a ‘silent heat.’

Split heats are more common among small dog breeds, especially for their first one. They might have swelling and a little vaginal discharge that goes away before the dog ovulates. 

Then, they ovulate later (and they’re able to get pregnant) even though they’re not bleeding as you’d expect during that stage of their heat. 

This is confusing since it goes against most of what this article has discussed.

How does this happen?

An article from Advances in Animal and Veterinary Sciences states that this is likely caused by an insufficient amount of the hormone gonadotropin. 

This could be a potential sign of hormonal abnormalities that affect your Chihuahua’s fertility… 

Be sure to talk to your vet if you notice your dog isn’t bleeding despite being in heat.

Then, there are ‘silent heats.’ Silent heats are basically what they sound like: heats where your dog ovulates but doesn’t have physical signs or bleeding. 

According to Dr. Cheryl Lopate of Wilsonville Veterinary Clinic in Oregon, your vet can diagnose a silent heat by looking at cells from your dog’s vagina.

This process is called vaginal cytology.

This isn’t a problem most of the time, at least when it comes to your Chihuahua’s health. It’s just hard for you since you won’t know when to protect her from intact male dogs.

Talk to your vet to rule out any potential health problems, just in case her silent heats are a result of an underlying problem. 

#9: Are Chihuahuas pads and diapers worth it?

Your dog’s heat can be messy unless your dog happens to have a silent heat, and you can’t control the flow of their discharge. 

You probably don’t want to wash your nice bedding after your dog cuddles with you. 

And you probably don’t want to follow your dog around, cleaning up after them. Plus, she’ll probably be cranky and annoyed with you.

So: Having your Chihuahua in some kind of protective covering during heat is worth it! 

Heat pads, heat diapers, and heat panties can protect your home. They also stop your dog from licking herself excessively. 

If she doesn’t lick herself, then you can keep better track of where she is in her heat cycle.

As we’ll get into, there are several options, and they can also be ways for you to dress up your dog in cute prints or designs.

But what are the downsides?

  • First, your dog could hate wearing it. She’s probably not at her best. Having to wear something on her butt when she’s usually naked won’t make her feel any better.
  • Second, it doesn’t stop male dogs from trying to mount her or even mating with her. Dogs can and likely will easily tear through them, especially if a female dog is at the peak of her heat.
  • Third, you’ll have to change them regularly. Keeping your dog in a damp diaper can cause rashes and discomfort. That usually isn’t a problem for many owners. They’re already with their dogs a lot. It also takes less time to change them than it does to take them out.
  • Lastly, diapers are an added cost. It’s not much, but it’s worth pointing out. We’ll go into those costs next. 

4 tips for managing your Chihuahua’s heat

Now you understand the heat cycle! It’s not too complicated. Now you have a general idea of what you should and shouldn’t do.

You can take these tips and make your Chihuahua extra cozy and happy.

#1: Invest in quality diapers, pads, or dog panties

As we’ve discussed, putting your Chi into diapers or panties during her heat will keep her and your home clean. 

Buying them and keeping them in your home at all times is a good idea. This will prevent you from rushing to buy them online or at a pet store last minute.

You can go with a disposable option, like a baby’s diaper, which is the most convenient. Since Chihuahuas are so tiny, you’ll probably have to get a specialty dog diaper.

But if you can’t get those, you can take a baby diaper and cut a hole for her tail to poke out.

Washable diapers are great if you don’t want to use a disposable diaper. You’ll have to do more laundry, but you’ll create less waste.

You can also use both disposable diapers and cloth panties over them to keep them on. 

These panties come with cute patterns and fun colors. People won’t even know they’re there for functional reasons!

But what if your dog hates wearing anything, which we touched on before? It’s not uncommon for a dog to hate wearing clothes.

Pee pads are a great option. They’re widely available, and your dog won’t feel confined.

You’ll have to make sure she’s on top of one at all times. This might be a pain, but it’s better than nothing.

#2: Stock up on her favorite foods

Cute Chihuahua Meme Cookie

Your Chihuahua’s appetite will likely change during her heat. She might not want to eat anything at all. Or, she might not want her regular food even if it’s her favorite.

To make sure she’s getting enough nutrition, encourage her with some special foods.

Say your dog only eats dog food when she’s not in heat. You could give her a few pieces of cooked chicken with that if she likes chicken.

Or, you could give her more dog treats. Find whatever she likes, so she doesn’t under-eat.

But on the flip side, don’t overfeed her either. Human foods can be high in calories, which could make her gain weight.

Many human foods are toxic to dogs too. The AKC has lists of human foods that dogs can eat here and here.

#3: Keep everyone calm and comfortable 

Your dog can easily pick up on your energy, which affects theirs. 

Basically, if you’re tense, then she’ll be tense. If she’s tense, she could act out in ways that make you tenser.

Since you can’t control your dog’s moods easily, you can start with your own. 

Even if your dog is particularly frustrating, don’t yell at her. Keep your voice low and calm. Give her extra attention and head rubs.

If you have a lot of stress going on, you can release it through:

  • Yoga.
  • Exercise.
  • Journaling.
  • Meditating.

If you have small kids, make sure they don’t bug the dog or create too much noise around them…

There are also ways to relieve your dog’s stress with supplements. Check-in with your vet before you start giving your dog anything new. 

There are plenty of calming aids that you can find on Amazon. Your vet likely has some recommendations as to which ones are safe.

Many owners claim that CBD oil (a non-psychoactive oil derived from hemp plants) calms their dogs…

It’s a big trend in the wellness world. People claim it helps everything from seizures to insomnia.

However, many experts aren’t fully sure if it’s truly helpful for animals. There haven’t been many studies on it yet. Discuss it with your dog’s vet.

Weighted vests like Thundershirts can calm dogs down if you don’t want to give them any medication or supplements. They’re almost like a hug for your dog. The weight makes them feel protected, which calms anxiety.

You can also use them whenever your dog is stressed outside her heat. They’re great at the vet or near fireworks shows.

Handle her body carefully during this time. Even if she’s fine being picked up, make sure not to move her too abruptly, as this could stress her out.

A free option to calm your dog  is soothing music, like this:

Music is especially helpful if you have to leave her alone for any period of time. You can also give her stimulating toys to keep her mind occupied.

In general, pamper your Chihuahua a little to keep her happy. She deserves it.

#4: Use a little menthol on her tail if male dogs are an issue

This tip doesn’t keep male dogs away entirely, but it could throw some males off your dog’s scent for a little while.

Rubbing a little menthol (like Vicks Vapor Rub) at the base of her tail can hide her scent. It’s best to use it when you have to take her outside. 

However, she (or another dog) might try to lick it off, which isn’t good. You can use it underneath her diaper to prevent this. You can use it on the outside of her diaper too.

Final thoughts

Your Chihuahua’s heat is natural, so there’s no need to panic about it. You can keep her happy and healthy during it with research and effort.