Canine Menstrual Cycle | How to Help | Canine Pregnancy

Let’s just get right to it… do dogs have periods?

Yes, a female dog has a menstrual cycle—unless she’s spayed. Though a female pooch doesn’t experience her periods in the same way a human female does, all kinds of mammals have similar basic reproductive organs. Canines experience their own version of periods. If you’re opting not to spay her during this time, you need to make sure your sweet pup stays as safe and comfortable as possible.

If you have a dog in heat, here’s some info on what you can expect – and, even better, what you can do to get her through it.

How the Canine Menstrual Cycle Works

female dog menstrual cycle

While human females will usually go through their reproductive cycle – the process of preparation for egg fertilization – in about 28 days female dogs experience their estrus cycle around every 6 months. And during that time, bleeding (or a bloody discharge) can occur on a relatively regular basis.1

So if you happen to notice a few drops of blood on the floor, but you can’t find a cut or wound on your pup, she’s probably in heat.  

Now, there are four stages of a dog’s heat cycle. Here’s a quick look at each of them:

1st Stage: Proestrus

The average length of this stage is nine days. But some dogs get through it in as little as three days, while it can take more than two weeks for others.

Periods during proestrus usually result in a reddish-brown bleeding or discharge. Even though the dog’s body is preparing for a potential pregnancy, females will reject any male dog’s advances during this time.2

2nd Stage: Estrus

In this stage, the dog’s discharge will vary in color. It might have a pinkish hue one day and be a deep red the next. Some days it could be almost clear.

Estrus is the period in which your dog is “in heat”. In this stage, the female might seem extra affectionate toward males because she’s officially ready to mate. You might notice a female lifting her tail to one side around male dogs, or poking them with her nose. She’s trying to flirt or get his attention.

A dog in heat might urinate more to “mark” her territory. This is because her urine contains compounds that signal to male dogs that she’s in estrus. Which is why males might suddenly start showing up outside your home or yard. Some dogs will also experience an increase in body temperature during this time. Their heat cycle will then last anywhere between 2 – 4 weeks.3

3rd Stage: Diestrus

The third stage of the heat cycle is the longest. It can last two months or more. A female dog won’t accept a male during this time. However, even if she’s not pregnant, she might exhibit motherly behavior. For example, she might be overly protective of a toy or another pet in the home.4

4th Stage: Anestrus

Anestrus is the final stage of menstruation where a dog’s sex hormones are relatively calm.5

What To Do When Your Dog Is In Heat

A female dog will usually go through estrus every six months. But some smaller breeds might go into heat as many as four times a year.

caring for dogDogs will usually begin estrus for the first time at 9-12 months of age.6  About 10 days into their cycle, dogs are usually at their most fertile but a dog can still become pregnant right up until the last day of estrus.7

It’s important that you know how to care for your female dog during this “heat” period and ensure that she is safe and comfortable. But don’t panic. Your dog is going through something that might be stressful but is perfectly natural. And although it can be messy or damaging to furniture, pet stores now offer doggy diapers that help to contain the blood.

In addition to doggy diapers, are a few ways you can help your dog (and yourself) get through her cycle:

1. Keep her away from male dogs

You will need to be extra vigilant with a dog in heat as male dogs will seem to come out of nowhere. If you belong to a training group, or love the dog park, it’s a good idea to avoid these during this time. A male and female dog will find any chance to mate – and do it quickly – if given the chance.8

2. Keep an eye on her at home

Even when you’re in your own backyard, you will, unfortunately, need to keep a close rein on your pup. Don’t underestimate the ability of a male dog to jump your fence, or even try to mate with her through a fence. When you let a dog in heat outside, watch her at all times. If necessary, put her on a leash before you take her into the backyard.9

3. Use a leash at all times

No matter how obedient, slow, or mild-mannered you think your dog is, when she’s in heat everything goes out the window. Nothing can beat a dog’s natural mating instinct. If she smells a male’s scent, it can make her unresponsive to anything you tell her.

Some suggest that you should bundle your dog up into the car and drive a few miles away from your home before walking her on a leash. This breaks the trail that your dog in heat leaves behind so that male dogs can’t follow her home, even hours afterward.10

 4. Keep her calm

Estrus is a very trying time for a dog. She might become anxious or easily agitated. Talk to her in soothing tones and give her a lot of extra attention whenever you can. Do what you can to minimize excitement. Make sure that any small children play with her gently. Make time to gently brush her coat, or give her a little massage.11

5. Keep your windows and doors closed

We all know that canines have one of the keenest senses of smell on the planet, so there’s no chance that you’re going to be able to hide the smell of your females pheromones on the breeze. In fact, pheromones are designed to be picked up by male dogs from miles away.

If you like to air out your house now and then, now is probably not the time. Keep your doors and windows shut until her estrus cycle is complete. Otherwise, you increase the chances of multiple unwanted visitors showing up.12

Understanding Canine Pregnancy

If your female dog does get pregnant during the heat cycle – whether intentionally or not –  you have only about nine weeks before her puppies are born.

Here’s what to expect during the dog gestation period:13

Week One – mating and fertilization occur.

Week Two – cells begin to grow and separate and the tiny embryonic puppies move into the uterus.

Week Three – Embryos begin to implant into the uterus, which means they can start to receive vital nutrients from the mother. The fetuses are no longer than ⅓ of an inch at this stage.

Week Four – The eyes, spines, and faces begin to develop and the fetuses will grow to around ½ an inch. Your dog’s teats may begin to swell. At four weeks you should begin to limit rough play and strenuous exercise.

Week Five – From here on out the puppies will be less susceptible to developmental issues. Their toes, claws, and whiskers begin to grow. Your dog’s weight gain will begin to become noticeable and she will need to have her food intake increased – smaller meals at more frequent intervals is best.  A vet will usually perform an ultrasound at 5 weeks.

Week Six – Puppies start developing their skin color and markings and this is when the mother’s energy requirements will be at their highest. High-quality puppy food is recommended during this time so that the puppies can get the nutrition they need.  

Dogs Have Periods | Dr MartyWeek Seven – Don’t be alarmed if your dog starts shedding belly hair in week seven. This is normal. The puppies are almost completely formed and their skeletons will now solidify.

Week Eight – Your dog could go into labor at any time now, so make sure you’re prepared. She may begin ‘nesting’ and you may even be able to see or feel the puppies moving about. Towards the end of week eight, she’ll start producing colostrum, then milk. Continue to let her eat as much as she will take.

Week Nine – Your dog should be nice and familiar with her whelping (birthing) bed in a quiet place of the home. An area that’s also easy to clean. Don’t be concerned if she becomes quiet, introverted, or if her appetite diminishes.

The Last Word

Menstrual cycles are a natural part of life for your female dog – just as they are for female humans. So, there’s no reason to let your dog’s cycle stress you out. Just take a few simple precautions and you and your precious pup will get through it just fine.

When answering the question, “Do dogs have periods?” it’s important to remember that dog’s who have been spayed do not have periods. And, if you don’t plan to breed her, there is always that option to spay your dog. Spaying is the removal of the female’s reproductive organs (ovaries, fallopian tubes, and uterus) and prevents her from falling pregnant. Spaying will also eliminate her heat cycle.

Article updated: June 22, 2018

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