Dog Pregnancy – Signs, Symptoms, and How Your Unborn Puppy Develops
Another great article from Sarah Holloway
Sarah Holloway takes a fascinating look at dog pregnancy and the secret world of the unborn puppy!
Today we are going to be looking at the journey your puppy made from conception to birth.
You’ll learn about the early signs that a female dog is pregnant, find out how long dogs are pregnant for and discover how the puppies develop week by week.
We’ll also consider the steps that need to be taken in looking after your pups’ mom in the weeks before birth. We’ve also included a brief look at what causes phantom pregnancies, and why some pregnancies sadly fail.
Dog pregnancy – do you want to breed from your dog?
If you’re thinking about breeding from your own Labrador you’ll find some interesting information here too. But the best place to begin that journey is with this article : Should you let your Labrador have puppies.
There’s a lot to keep in mind if you’re considering breeding your Labrador, and there are issues you must think on carefully before you make a decision. The above article will help you.
A lot of preparation goes into planning a mating – from choosing the right mate, getting the right health tests carried out, to making sure the mating goes smoothly. These are all topics in their own right.
But today, we are going to focus on the pregnancy itself. So we’ll pick up the dog’s pregnancy story from right after mating. First let’s look at how long we can expect dog pregnancy to last.
How long are dogs pregnant?
Dog pregnancy is often considered to last for around nine weeks. So that’s one week of dog pregnancy for every month of human pregnancy.
But it’s not quite that simple. Let’s take a closer look.
If a Labrador’s pregnancy is planned to the smallest detail, and her owner knows exactly when she ovulated, then her gestation period can also be predicted with uncanny accuracy.
The majority of litters across all breeds of dog are born on the 63rd day after ovulation.
In 2001 a team at Utrecht University in the Netherlands included 31 Labrador retrievers in a study of how breed and litter size affects dog pregnancy length.
They found that because Labradors tend to carry large litters they also have slightly shorter pregnancies – 61.5 days on average.
But what if you took a more fateful approach to mating your girl, and you don’t know exactly when she ovulated?
In this case, expect her to give birth 55 to 64 days (eight to nine weeks) after mating.
Why the wide range? Let me explain…
Predicting the gestation period of dogs
As for all mammals, dog pregnancy begins when sperm fertilizes an egg.
Dog sperm can live inside a dog for up to ten days, and whilst it does gradually degrade and become less likely to fertilize an egg, it still means that a girl mated ten days before she ovulates could still get pregnant.
At the other extreme, a female dog’s eggs can survive for up to six days after ovulation, although they will also decline in quality over this period, so that late breeding is more likely to be unsuccessful or result in smaller litters.
So in theory, there’s a sixteen day window during which a female dog can get pregnant.
Now if you’re doing the sums, that’s a sixteen day window for getting pregnant, but a nine day window for giving birth.
How is that possible?
Ongoing research at Nippon University in Japan suggests that eggs which are fertilized late then progress through the early stages of development more quickly, so that the puppies are still born a predictable amount of time after ovulation.
Amazing. Now you may be wondering how many babies you might expect.
How many puppies is my dog likely to have?
In 2010, scientists at the Norwegian School of Veterinary Science conducted a retrospective study of over ten thousand dog litters, to find out what factors influence litter size.
Their study included 223 Labrador litters, which ranged from one to thirteen puppies, and an average of seven.
They found that litter size is closely linked to breed size: Labradors are large breeds, so they tend to have large litters.
(By comparison, toy breeds and small breeds had an average of three or four puppies in a litter.)
They also found that litter size decreased as the mother got older, and that litters conceived by artificial insemination produced fewer puppies than natural mating.
Studies have also shown that litter sizes decrease when dogs are more closely related.
So now your dog has mated but you’re still not sure whether she is pregnant. So what happens next?
Recognizing signs of pregnancy in dogs
A female dog is unlikely to show any signs of pregnancy in the first couple of weeks.
In this time, the fertilized egg divides into a round ball of cells called a blastocyst, which travels through a female dog’s reproductive system until it reaches the uterus and finally anchors to the lining of her womb (the technical term for this is “blastocyst invasion”, how lovely!).
Only once the embryo attaches to the lining of the womb do the cascade of hormone changes associated with pregnancy begin, and bring with them their tell-tale symptoms of pregnancy.
What dog pregnancy symptoms might you expect to see? Do dogs suffer from morning sickness for example?
Do dogs get morning sickness?
Well, just like in humans those pregnancy hormones might can make a female dog feel a bit nauseous.
So she might go off her food, and even vomit a little.
Everything happens in fast forward compared to a human pregnancy through, so morning sickness in dogs only lasts a few days.
Other signs of pregnancy
Some female dogs show signs of tiredness or listlessness in very early pregnancy because of all the hormones being released. At around 30 days you might notice that her nipples have started to change in color and size.
At this time you might also see a discharge of thin clear mucus from her vagina. As long as the mucus is clear you don’t need to worry – this is quite normal.
You should have your dog checked out by your vet if a discharge has blood in it, or if the mucus is not clear or has a bad smell.
But just like in the first two months of a human pregnancy, the first couple of weeks is often outwardly fairly uneventful. And despite their best efforts at symptom spotting a Labrador might not show any early signs to those who are watching her closely.
Confirming signs of pregnancy in dogs
Unless a Labrador’s owner has had a lot of breeding experience, they will need a vet to confirm whether mating has resulted in pregnancy.
Confirming pregnancy in dogs early on (rather than waiting until it’s plain to see), is vital for planning the best care for a female dog and the best outcome for her puppies.
There are several ways of confirming pregnancy in dogs – vets are happy to discuss these if necessary. Let’s look at some of the diagnostic tests available
Dog pregnancy test: abdominal palpation
Abdominal palpation means very carefully massaging the dog’s tummy to feel for puppies growing in her uterus.
It’s a completely no-tech approach, and the one vets and breeders have relied on since time immemorial.
Abdominal palpation is most effective for detecting pregnancy in the fifth week after mating, when the embryos are a little over an inch long (three centimeters), but not yet cushioned by amniotic fluid.
Someone with a lot of experience might be able to detect embryos by palpation as early as three weeks after mating and as late as six weeks.
Abdominal palpation is not always conclusive, for example if a dog is nervous during the examination and tenses her stomach muscles, if she is overweight, or if she’s only carrying one or two pups and they are tucked right up inside her abdomen.
When this happens, the vet might recommend one of the following alternatives for confirming pregnancy.
Using ultrasound to confirm pregnancy in dogs
Ultrasound scans are seen by vets as the “gold standard” for finding out if a dog is pregnant. They are reliable and you can be reassured from as early as three weeks after mating.
Many breeders now use these scans routinely.
Depending on how sophisticated their ultrasound equipment is, a vet might also be able to predict a girl’s due date using the scans.
Using radiography (x-rays) to confirm pregnancy in dogs
Your dog’s pregnancy has usually been confirmed by physical signs and symptoms, palpation or ultrasound by the time the puppies they show up on an x-ray.
This only happens once the unborn pups’ bones have started to calcify after six to seven weeks and sometimes even later.
The great advantage of an x-ray is that different skeletal structures, for example the skull, the spine and the teeth, become visible in a very specific order and at very predictable times.
If the pregnancy wasn’t planned, and no-one is sure when mating took place, x-rays can confirm, sometimes to the day, how far along the pregnancy is.
Radiography is also the most reliable way of counting how many pups a dog is carrying.
Can you give a dog a pregnancy test?
So there are multiple of ways of finding out if a dog is pregnant, but is it ever as simple as getting them to pee on a stick?
I’m afraid not.
Since 2010 Pfizer have produced a pregnancy test for dogs called the Witness Relaxin test,
which detects elevated levels of relaxin hormone secreted by the placenta during pregnancy.
However, the test needs a sample of blood plasma, so requires a visit the vet to have blood drawn and the plasma separated.
The tests are widely available online, but don’t seem to have gained much following with vets, so it’s wise to ask ahead whether a vet keeps them in stock.
These tests can usually detect pregnancy from about 22-27 days after mating But be warned – they can also produce a false negative result. If you are pretty sure your dog should be pregnant the test should be repeated after a week.
At $20-$30 a test in a box of five they don’t come cheap. But they don’t need to be refrigerated and have a shelf-life of around 18 months.
And finally, just in case you’re tempted to try: human pregnancy tests detect the presence of human chorionic gonadotrophin hormone – they cannot detect pregnancy in dogs!
But there’s no time to rest on your laurels, because dog pregnancy is short, and those puppies are going to be here before you know it.
Next we’ll look at the stages of a dog’s pregnancy, and caring for the female dog during her pregnancy.
The stages of dog pregnancy
Let’s rejoin our unborn puppies four weeks after fertilization.
They’ve anchored to the lining of the uterus, and the placenta now delivers nutrients from mum to pup.
The 4 week pregnant dog: days 21 – 27
The fourth week of pregnancy is an exciting time to be a dog embryo.
They’re only 15mm long, but their nervous system is developing, and other cells are differentiating into tissues, organs and bones.
If your dog has an ultrasound scan in this week, you’ll be able to make out the puppies’ heartbeats for the first time.
This also the week when embryos are most vulnerable to damage which could impair their development later.
The 5 week pregnant dog: days 28 – 34
The mother Labrador to be, and her pups, have made it past the halfway mark!
The puppies’ limbs are beginning to form, and most puppies which are healthy at this point will remain so for the rest of the pregnancy.
The 6 week pregnant dog: days 35 – 41
As the puppies grow inside her, you’ll finally begin to notice your girl’s tummy begin to swell, and her nipples will get noticeably darker. Mom might also start to become uncomfortable and want to rest more.
A clear discharge from her vagina at this stage is also no cause for concern. Meanwhile, her puppies are beginning to produce the pigments in their skin which will determine the markings in their coat when they’re born.
The 7 week pregnant dog: days 42 – 48
In week seven the bones of the puppies’ skulls and spine harden and become distinct on an x-ray. If you’re lucky you could even feel the puppies moving in her tummy.
Some female dogs might also begin shedding their hair on their tummies this week as well. And the development of her breasts will be clear to see. This is a completely normal part of the body preparing for birth.
The 8 week pregnant dog: days 49 – 55
The puppies’ limbs and pelvic bones are calcified and discernible on an x-ray too now.
As her due date draws near, mom starts to produce colostrum – the nutrient rich first milk her puppies need in their earliest days.
The 9 week pregnant dog: days 56 – 63
This week an x-ray will even pick up the puppies’ teeth.
They are ready to come out into the world, and the nine week pregnant girl will be nesting in preparation for the impending birth.
Your vet may suggest that you to start taking her temperature several times a day: when it drops to below 100°F, birth usually follows within 24 hours.
You can start watching for the signs that mom is going into labour.
Going into labor
There are a few behaviors which indicate that birth is imminent. This can last for six to twelve hours, or even longer, while the cervix dilates and prepares for delivery.
Human moms even show some of the same signs like being restless and losing their appetite. Even nesting behaviour – an urge to clean and tidy up the house.
Watch for the following signs:
- restless and pacing, followed by falling asleep
- panting and shaking/shivering
- returning often to the place where she plans to give birth
- licking herself
- becoming quiet and introverted
- going off her food
- possible vomiting.
Caring for a pregnant dog
Pregnancy is a time to treat your Labrador with more love and care than ever, and it’s vital to include your vet in planning her care as early on as possible.
Book her in for a checkup around three weeks after mating to confirm the pregnancy.
In the meantime, don’t administer any flea or worming treatments (if she falls due for one, call your vet for advice).
Remember that her puppies will be at an especially delicate stage of development around weeks four and five, so start limiting strenuous exercise and rough play at this time to keep mom and pups safe.
However, you’ll want to prevent her from getting fat and make sure the her muscles keep in tone. This will help her to be strong during labor.
She can enjoy normal activities and you can take her for regular walks. Once she is about six weeks pregnant she’ll tire more easily – let her set the pace.
Around this time she’ll also be starting to think about where to give birth. Prepare somewhere warm and enclosed with lots of blankets, and encourage her to start sleeping there.
If you don’t have an experienced mentor to help you through whelping and lactation (and even if you do) you’ll need a copy of the dog breeder’s bible – it’s called The Book Of The Bitch (in the UK the word bitch is a commonly used term for female dogs).
Feeding the pregnant dog
The first vet’s appointment is the time to discuss what food the pregnant dog should be eating during pregnancy, and if she needs any supplements.
For the first couple of weeks after mating, you can simply continue feeding her normally.
If she has morning sickness try to tempt her with smaller meals at more frequent intervals. Don’t worry, her appetite with return soon, and the puppies aren’t in any danger if she doesn’t seem to eat much for a few days.
As the pregnancy progresses your girl’s appetite will increase – especially from week 6 onwards. She does need extra calories to support her pups’ growth – but watch her weight. A pregnant dog should not gain more than 50% of her original weight.
The mom’s growing uterus might not leave much room in her tummy for extra food. To get round this, your vet may recommend feeding her a suitable brand of puppy food. Puppy foods are high in calories and quick and easy to digest: perfect for supporting a pregnancy.
There’s a lot of contradictory advice out there, so let your vet guide you as to how much food she needs at each stage of pregnancy, and whether she would benefit from additional vitamins.
You might have heard people talk about giving pregnant dogs calcium supplements.These are for during and after labor.
Do not give your dog calcium supplements during pregnancy because they can cause problems during labor and lactation The mum does need more calcium for the pups developing inside her, but her own body takes care of this.
She produces a hormone which naturally increases calcium levels in the blood. When supplements are given too early not enough of the hormone is available after birth to ramp up calcium for lactation, even with supplementation.
Dogs and pregnancy: when things don’t go to plan
Hopefully when your dog gets pregnant it will be the result of careful planning and culminate in the arrival of a healthy litter of puppies.
But life does not always run thus, so this article wouldn’t be complete without information about the other possible outcomes.
Phantom pregnancy in dogs
Phantom pregnancy, or pseudopregnancy, is the appearance of dog pregnancy symptoms in a female dog who isn’t pregnant.
It’s a peculiar phenomenon – whilst it’s not unheard of in other animals, it is rare outside of the dog world.
A dog experiencing phantom pregnancy may gain weight, have enlarged, darkened nipples, display nesting behavior and even produce milk.
A recent study among vets also reported changes in behavior. The most common were collecting and mothering objects, and aggression. The most usual physical signs were enlarged breasts and milk production.
A phantom pregnancy can either be a puzzle if you know for a fact your girl didn’t mate while she was in season, or a heartfelt disappointment if you thought a carefully planned mating had been successful.
Phantom pregnancies are usually self-limiting and the symptoms end of their own accord.
It’s important to stop your dog from stimulating her milk production by licking her nipples though, as this can prolong the phantom pregnancy.
If you are at all worried about your girl during a phantom pregnancy, it’s always best to see your vet, who may recommend using synthetic hormones to bring it to an end.
Mismating: managing unwanted dog pregnancy
Just like in our human lives, even when we try our best to do everything right, accidental pregnancies still happen.
Mismating is the term we give to unplanned breeding between two sexually intact dogs.
Your vet will be able to discuss your options with you if your Labrador has mismated.
Pregnancy loss in dogs
Happily, miscarriage – known as spontaneous abortion – isn’t very common in dog pregnancies.
Embryos which are lost early in pregnancy are reabsorbed by the mother, so we don’t know very much about how often it happens.
Spontaneous abortion in the later stages of pregnancy is rare. When it happens it is usually the result of either an imbalance in the hormones supporting the pregnancy, or an infection of the uterus.
If your girl loses a puppy in the later stages of pregnancy you’ll notice abnormal bleeding from her vagina, and possibly find the lost puppy.
Always take your Labrador to the vet if she loses a pregnancy. She’ll need a checkup to make sure she’s healthy. If the loss was the result of an infection then she will need to be treated.
It is also possible to miscarry one or more puppies, and carry the rest of the litter to term. Your vet will be able to tell you if your dog is still pregnant with other puppies.
Dogs and pregnancy
Phew, we’ve made it through this potted digest of dog pregnancy, and there was a lot to take in!
Your Labrador’s pregnancy can be a time of mixed emotions, both exciting and nerve-wracking.
By planning the pregnancy in advance and consulting with your vet from the very beginning, your dog’s pregnancy should be happy and healthy.
Pregnancy and childbirth is a natural process for all mammals. Dogs are mostly able to manage quite well on their own and instinctively know what to do. During whelping your role is to be there, offer comfort, and to notice when things don’t go according to plan.
Of course you can arrange for help and support from someone with experience in caring for a dog while she’s giving birth. Definitely be sure to have phone numbers to hand in case of an emergency.
The book I mentioned above will give you all the information you need about the whelping process and caring for your new babies.
This article has been revised and updated for 2019.