Now, some may read that post title and think, “Why not just avoid the whole problem by spaying your corgi before she even comes into season to begin with?” And that would be an understandable thought to think. There is a lot of cultural precedent to back up that thinking. Spaying and neutering at 6 months has been the standard practise for a long time now, with some dogs even being desexed as early as 8 weeks old. But more and more research has suggested that this may have long-term health and behavioural implications, and delaying spay/neuter until full maturity might be a better course.

I think it goes without saying, but I am by no means in the veterinary medicine field. I would never give veterinary advice on this blog. I save my unprompted and unprofessional advice for family and friends. Kidding! Mostly. Seriously though, you should do your own research on this. I’m working on gathering a bunch of links to get you started, and will come back here and link to that page when I’m done.

Delia is on a non-breeding contract, and she will be spayed. The question was only of when. Her breeder recommends waiting until she is fully grown. From all of my research, this is basically the consensus amongst the Pembroke Welsh corgi breeding community. My vet was also supportive of that decision.

Before her first heat, you can see how structurally immature Delia was. She’s ADORABLE of course, but looks lanky and her chest is very shallow. Imagine removing significant hormones at that time!

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And this is how she looked immediately after her first heat. The difference is subtle. She still wasn’t done growing by any stretch. But you can see that her chest has deepened just slightly and her topline levelled out.

I really went back and forth on whether to spay her after the first heat or let her go through one more. I’m really glad that I waited. Just in the few months since her first heat, you can see the difference. She still doesn’t have a deep chest or thick bone structure (and she never will—but she’s adorable and has got a very athletic build that can MOVE!) However, she has definitely blossomed since then, and she’s going to continue filling out until probably close to two, as her breeder told me that her dam did. I’m really curious to see the changes after this next heat.

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So, even if you don’t intend to breed your corgi (and for the vast majority of people, it would be most responsible not to!), there is still a possibility you might choose to let her undergo one or more heats before spaying. If that’s the case, I have some tips for you!

At what age will my pup go into heat?

It’s not helpful but it’s true: every dog is different! But there are some general things that can be said. 6 months old is the average, which is why spay/neuter at 6 months is the norm if you want to alter your dog before they reach sexual maturity. But individual dogs range widely outside of that average. In general, smaller breeds tend to mature faster than larger breeds, with giant breeds being very slow to mature. So some dogs may go into heat as early as 4 months (that’s just 16 weeks, folks! A baby!), whereas for some giant breed dogs, their first heat may come as late as 2 years. Remember that Pembroke Welsh corgis are really a medium-sized dog on short legs, so in general their first heat tends to fall a little later than the smaller breeds. 9-11 months is average. But again, individuals will vary. Delia’s first heat came the day she turned 7 months old.

The best advice is to ask your corgi’s breeder at what age females of her lines tend to begin their estrous cycles. Particularly your dog’s dam. And I have no empirical evidence to back this up, but I think the most accurate guess you could possibly gather would be if your dog has older full siblings from a previous litter. I say this because Delia and her two littermate sisters all went into heat at pretty much the same time. Delia was first—February 2nd. Her sister Akasha followed on February 16th, and finally her sister Riley on March 7th. So all within a little over a month of each other. She has two full sisters who are still babies from the repeat breeding, so we’ll see if my theory holds out when their times come!

How will I know?!?!

You’ll know.

Quick Story Time: Skip If You Don’t Like Fluids

So quick story time: when Delia was 5 months old, she was laying on my bed one morning and when she got up she left behind a pretty sizeable puddle of pinkish discharge on the sheets. I immediately sent a picture to her breeder and asked if I should rush to the ER vet (1,000 shout-outs to her for being so awesome—I can’t imagine how many puppy-parent-panics she so graciously responds to, and that kind of support is exactly why you should get your puppy from a knowledgeable, amazing, caring breeder like her). She said 5 months is early, but absolutely possible. She said there was no need to go to the ER vet, but I should get her checked out to rule out a UTI, and gave some advice on how to care for her in the meantime.

I ran out and got a couple baby onesies and used in combination with a menstrual pad to contain the discharge. There really wasn’t much of it, and none of it was bloody after that initial sighting. There is a pretty reasonably priced urgent care vet that I like going to for stuff like this, since our primary vet is so booked out usually. So after keeping an eye on her that first day (Saturday) and the next day, I took her in on Monday.

Since it was 2020, I couldn’t go in with her, but the vet came out and told me that it appeared to be just a case of puppy vaginitis, which is pretty common and usually resolves itself by the first heat. She gave me some keto wipes and an immune-boosting supplement to put on her food. She said she tries to avoid putting puppies on antibiotics when possible, as it’s not usually necessary. And sure enough, the infection cleared up pretty quick.

Delia said, “See? I told you I didn’t need to wear that silly outfit!”

We had dogs go into heat when I was little for sure, but I never was very involved with that. Looking at my poor little puppy’s slightly inflamed vulva, it had seemed possibly swollen to me. But once she actually went into heat, the difference was unmistakeable. Don’t overthink it—the signs are not subtle. (unless it’s a silent heat, but let’s keep it simple today.) You’re gonna know.

What might indicate my dog is going into heat?

There are various phases to the Oestrous cycle, but the time when we consider a dog to be in heat or in season encompasses only four of them: pro-oestrus, oestrus, metoestrus, and dioestrus. Pro-oestrus is the phase where your dog’s body prepares to mate. This encompasses the first signs you will see and the portion of the cycle where the dog is having the bloody discharge that we associate with the a female being in season.

1. Dogs acting weirdly around your dog.

Just before Delia went into heat for real the first time, I took her to the dog park and there was an intact male Doberman who pretty much followed her around with his nose up in her business the entire time, even though she was very keen to avoid him and kept telling him off. A little later, a female dog snarked at her for seemingly no reason. Dogs seemed to be sniffing her a little longer than usual, interested in her urine just a little more than usual—lots of subtle stuff I really only picked up on in hindsight.

2. Changes in your dog’s own behaviour

This can be subtle things you might not notice, such as holding her tail closer to her body. You’ll likely notice the almost obsessively thorough and frequent licking of her lady bits—especially if the sound of dogs licking themselves drives you batty. You might find she’s more short-tempered or even outright aggressive toward dogs she normally gets along well with, or on the other hand, flirtatious. I’ve seen Delia flirt with a male dog, only to suddenly turn on him if he gets too interested and tell him off. (The male dog in question is my golden who has been neutered for 12 years, by the way. I don’t let her around other male dogs during heat! And even with him, they’re supervised.) These apparent mood swings are due to the fact that the female is advertising that she will be ready to mate soon and courting potential suitors, but she isn’t ready quite yet, and won’t put up with over-eagerness. Humph!

There could be changes in appetite, and whether that’s an increase or decrease depends on the individual. For Delia, she seems to have slightly less appetite just before going into heat, but is ravenous during her heat.

I can’t find much about this by googling, but Delia also pants a lot when she is in heat, and I’ve seen other corgi owners post about similar experiences. They also might cry or vocalize for seemingly no reason.

You may also find that your girl is extremely needy and suddenly very clingy. When I first attempted to start writing this blog post, I found it pretty impossible because Delia insisted on planting herself on my abdomen and blocking my view of my laptop.

3. Physical Signs

Your dog’s external genitalia (the vulva) will swell and the skin might darken. You will likely see some bloody discharge, although some girls are incredibly fastidious, to the point that their owners report not really finding any blood. You can wipe her with a tissue to try and detect whether she is bleeding. You might also notice some swelling of the nipples—that’s the case with Delia.

What should I do during pro-oestrus?

As mentioned before, some girls are very fastidious, so some owners let them go au naturel during heat. Be aware that even the cleanest will probably leave some spotting when they’re sleeping, for example. And if they shake themselves off, blood can splatter pretty far (I speak from experience.)

Delia didn’t do a very good job of cleaning herself during her first heat. I would take her out to go potty, and she would come back inside with blood dripping down her fur. I couldn’t just put her onesie contraption back on like that, so I would put her in her crate hoping she’d clean herself off. No. She’d just sit there in her filth. I’d have to use baby wipes to clean her up. Thankfully this time around, she seems to get the idea a lot better, and she keeps herself very clean. So on days when she has a lighter flow, I’ve been able to let her free. But yeah, for most of us, we’ll need to do something to contain the blood in order to save our carpets and sanity.

I really like these surgery suits, especially because you can use them with a menstrual pad or baby diaper during heat, and then to protect the sutures after your dog is spayed. The only thing to note is that mine shrunk when I washed it, even though I followed the care instructions, and it no longer fits as well. I think it would still work for a surgery, but it doesn’t quite cover her butt enough to hold the pad in place anymore. So be careful with that. Otherwise it was probably the most comfortable option, and I’ll be getting another one for her to use post-spay.

You can also just use baby diapers, but those tend to fall off. We used them with family dogs in the past and had to keep a close eye, as they are definitely not escape-proof. Delia’s sister’s human got very creative with toddler underpants and bed clips as suspenders, so you could go that route as well!

The best option for me was an 18 month baby onesie + a menstrual pad. I wasn’t aware, but apparently Carter’s brand are longer than others, and that’s what we just happened to get. It’s a tight fit (though it stretches while she’s wearing it) so it’s good to know that other brands may be too short. At the beginning of her first heat, we had some 12 month ones from the vaginitis episode. Those were a very tight fit by the time her first heat rolled around, so after the first day I went out and got the 18 month. But since corgis can vary so much in size, it’s may be a good idea to get several sizes and try them on. Some corgis require a 24 month, but for Delia that would be too loose to hold the pad in place properly.

Here is a gallery of sad-girl-in-a-onesie pictures.

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Give your girl some extra love and attention if she wants it during this time. If the constant demand for your attention starts to feel exhausting, just remember that your dog doesn’t know what is happening to her (especially if this is her first heat), she may well be uncomfortable or in pain, an she is turning to you for comfort. Alternatively, some doges become grumpy and standoffish when they are in heat. And some swing back and forth. Just try to give your girl whatever she needs, whether that’s more affection or more space.

Especially for the first few days, your girl will likely be very tired and just want to rest. So let her! Her little body is going through a lot. Don’t allow family members or other pets to disturb her too much. Although our golden has been neutered for 12 years, he was still making an absolute fool and nuisance of himself, so I kept them separated as much as possible.

On the other hand, if your girl is feeling playful or restless, play with her! Take her out in your yard to run around (but speaking of the yard, I’m going to come back to that later). It’s even okay to take her on walks, provided there is no risk of her escaping (this would be a good time for something like a martingale or a very secure harness) and there is little risk of encountering off-leash dogs. In fact, as a courtesy to other owners, it’s best to only walk places where you are unlikely to encounter other dogs at all, so they don’t have to struggle to keep their dog under control when they’re just trying to enjoy a pleasant walk. Keep the walks short so you don’t overtire her. Also, expect that she will want to stop and pee on literally everything.

If you’re having her wear something to contain the bleeding, it’s a good idea to make her crate a place where she can be free of those constraints. I take out Delia’s bed and put a towel down, and I leave in her blankets which are washable. Sometimes when she comes in from outside, she’ll go straight to her crate, letting me know that she would rather have some time in there without the onesie on. I also crate her for bedtime during this time so she can sleep unencumbered.

How long will Pro-oestrus last?

Again, every dog is different, but on average, 9-12 days. But, the first season is not very predictable, as the dog hasn’t settled into a regular cycle yet. My breeder says “there is no normal for first heats.” So the bleeding could easily run for quite a bit longer than the average numbers you see. But don’t fear! It will be over before you know it. Promise.

Oestrus

The next phase is oestrus, which is when the dog is actually available for breeding and will allow herself to be mounted. The discharge will change to less bloody and more straw-coloured. You will see a behaviour with her tail which is called “flagging”, where she lifts her tail up and out of the way and may fan it in the direction of a male so that he catches her scent. She may be aggressive towards females, while the flirtatious behaviour with males will ramp up. During this time, she may make attempts to escape.

AT NO POINT DURING HEAT SHOULD YOU LEAVE YOUR FEMALE UNATTENDED AND UNPROTECTED!!!

Containment and management starts from the first sign of heat, not when you think the female is actually available to breed. Obviously if you have an intact male in the house, you should be extra cautious. Diapers, surgery suits, even belly bands for the male are not birth control. Never underestimate the lengths dogs will go to in order to mate. Keep them physically separated with as many barriers in place as possible. Not just one or two. Dr. Marty Greer, who specialises in canine reproduction, said: “Anybody that tells you that they’ve never had an accidental breeding, that owns both males and females that are intact at their house, is either lying to you or it hasn’t happened to them yet.” If this is true amongst experienced breeders who have LOTS of preventative measures in place, us average pet owners have no cause to be overly confident.

Just because you don’t have an intact male in the house is no reason to let your guard down. You should never leave your female unattended in the yard for any length of time. Not even if you are so sure your yard is completely secure. A male could bust his way in or your female could bust her way out. Dogs can and have bred through chain link fences. Things can go awry very fast, so be there to supervise, and consider even taking your female out on a leash like you did when she was a little bitty puppy.

What should I do now?

Keep doing what you’re doing! You may find the discharge has lessened enough that you don’t need a onesie, diaper, or other contraption anymore. Or you still may. During her first heat, Delia wore her onesie until all the discharge had stopped, which was about 16 days. Be extra vigilant to prevent an accidental breeding. And continue to ensure that your corgi girl is as comfortable as possible.

Metoestrus

The dog will no longer allow males to mount her, and her swelling will slowly start to subside. The discharge will stop. Her body will produce progesterone, causing her a uterine lining to develop in case the oestrus phase resulted in fertilization. The end is in sight!

Dioestrus

Progesterone is still being produced, which can cause a phantom pregnancy or pseudopregnancy. That happened after Delia’s first heat: her mammary glands became swollen, she lost her appetite but without seeming to lose weight, and she seemed to have less energy. The symptoms quickly resolved themselves, however.

And congratulations! You’re done!

What is pyometra, and how scared should I be?

Well, I say you’re done, but there’s still something to watch out for.

It’s a pet peeve of mine when people refer to heat as the dog “being on her period,” because actually *puts on nerd glasses* it’s not really like menstruation at all, other than the fact that both the bitch’s oestrous cycle and the woman’s menstrual cycle both prepare the body for possible pregnancy.

To sit you all back down in health class and run through an extremely simplified version of this, the menstrual cycle lasts on average 28 days. It begins with the follicular phase, where the brain signals the ovaries to prepare to release an egg. Next comes the proliferative phase, where the uterus begins to build up a thick lining (endometrium), as the canine does during metoestrus. The mid-point of the menstrual cycle is ovulation, where the ovaries release an egg into the fallopian tubes. This phase corresponds with the oestrus phase in the canine’s cycle. Then you have the luteal phase, where the sac (follicle) that contained the egg becomes a corpus luteum, and begins to produce oestrogen as well as progesterone. The progesterone levels peak halfway through this phase, which corresponds to a specific point in the oestrus phase in dogs. It’s complicated—read here if interested. Assuming there is no fertilization, the corpus luteum will break down, causing a drop in oestrogen and progesterone. This triggers menstruation, the breaking down and shedding of the uterine lining that is colloquially called being on one’s period. And it all begins again.

As you can see, in humans, the uterine lining thickens before ovulation, whereas in dogs it occurs afterwards. And unlike in humans, you may have noticed that there is no corresponding shedding of the uterine lining in the canine oestrous cycle. So where does it go?

It stays there. The uterine lining thickens in preparation for pregnancy…and then there is no pregnancy. If pregnancy continues not to occur cycle after cycle, the thickening and thickening lining begins to produce cysts. This cystic lining secretes fluids, and the uterine environment becomes ideal for bacterial growth. These accumulating fluids and bacteria cannot be expelled, as the muscles of the uterus cannot contract around the thick lining. This is called pyometra. Stretching my brain back to my medical terminology days, pyo means pus and metr means uterus. I have heard pyometra described as a pus-filled balloon.

As you can imagine, pyometra risk increases with the number of cycles that the female undergoes without becoming pregnant and whelping puppies, and thereby expelling the uterine lining. This is why, left to their own devices, as observed in village dogs or street dogs, the female will breed and ideally whelp puppies each cycle. It is why the current advice for breeders is to not skip too many heats in a row, letting years pass between breedings, as used to be done in order to give the dog “a rest” and allow her body to recover and return to the show ring before the next breeding. (That doesn’t mean breeding the female back-to-back for many years, puppy mill style. She will instead be spayed younger in her career.) And most importantly for us pet owners, it is why we should spay our females early in life. There is a conversation to be had about whether it is better to leave male dogs intact, but for females, their bodies are just not designed to keep going through cycles without becoming pregnant. Whereas humans are designed in such a marvellous way that makes it completely our choice. Thankful for that!

Anyhow, even though it is less common in younger dogs, it’s important to know the signs of pyometra and keep an eye out. Pyometra will usually occur from 2 to 8 weeks after the last oestrus.

There are two types of pyometra: closed pyometra and open pyometra. The distinction is according to whether or not the cervix is open. If it is open, you may notice pus or discharge, which can be bloody, but if it is closed you will not. This means that a lack of visible pus does not rule out pyometra. In a closed pyometra, the dog might accelerate more rapidly into serious illness, and the other symptoms might be more pronounced. Clinical signs vary widely, but can include:

• Fever
• Lethargic, listless, depressed behaviour
• Anorexia (loss of appetite)
• Vomiting and diarrhoea
• Excessive, diluted urination
• Excessive thirst

Time is of the essence, as the disease progresses rapidly to shock (think of toxic shock syndrome in humans) and death. The uterus can rupture, causing bacteria-laden pus to fill the abdomen (think of appendicitis). If you have even an inkling that your girl might have pyometra, get her to the vet. I know vet bills are expensive and it’s tempting to wait it out, but especially in a closed pyometra, the signs may be so subtle that if you’re waiting for that definitive moment, your dog may die. It’s very serious. So, particularly in those 2-8 weeks after her season, but also at all times, be vigilant for any signs of pyometra. And as soon as your breeder and your vet agree that it’s a good time, spay your corgi!

One Final Note:

Yes, evidence points that it is advantageous to allow a dog to go through one or more heat cycles before spaying. There is, however, no evidence to suggest that you should breed your dog before spaying her. Many pet owners feel the need to “let her experience motherhood one time” or similar arguments. This is anthropomorphizing the dog. Your dog does not need to be a mother in order to be happy, and she will not experience regret over not having had that opportunity. In fact, breeders report that some doggos do not appear to enjoy motherhood. I don’t want to spend too much time talking you out of this, but I found this really balanced article which considers the matter fairly. The bottom line is that I disagree with the notion that the presence of unwanted pets in this world means we should no longer be supporting breeders who preserve historic breeds and produce dogs that are healthy, behaviourally-sound, and suited to highly specific jobs (with the job of being a bomb-proof family pet being one of the most difficult of all, with a depressingly high wash-rate.) However, I do think it means that not everyone should breed their family pet. And in fact, most people shouldn’t. And that’s especially true if you got your dog from a highly responsible breeder who puts her puppies out on non-breeding contracts, making only rare exceptions for specific dogs. If you signed a contract, you signed a contract!

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That’s all I have for you today. I hope it helps you to know exactly what to expect. I know for me, even though we had family dogs who were in heat when I was growing up, and even a dog that my parents bred once under the guidance of her excellent breeder, I was very young and wasn’t responsible for dealing with that. And my foster dog Eleanor was spayed before she came into heat. So Delia was a new experience for me. Even though there is a wealth of reputable sources of information out there, there’s nothing quite like reading people’s first-hand experiences in a more personal tone to put your mind at ease.

So, take a deep breath! You’ve got this! It may seem scary and overwhelming at first, but there’s really not much to it. Number one is preventing pregnancy, and number two is protecting your furniture and carpets if you care. It will be over before you know it!

If you found this useful, that makes me so happy! Please consider subscribing to my blog (bottom of the page) so that you are notified of future posts. And have a lovely day!