How Long Are Dog Pregnancy Trimesters?

If you're a dog enthusiast or planning to adopt a pup, understanding your pet's gestation period can help prepare for their delivery.

On average, dogs undergo 63 days of gestation from when they are bred. This number may differ due to ovulation timing.

Veterinarians can determine the date of ovulation by monitoring progesterone and luteinizing hormone levels. This test is commonly done.

The first trimester

The initial trimester of dog pregnancy lasts 21 days, beginning when a female dog ovulates her eggs. During this period, there are few outward signs that your pup is pregnant; however, hormonal changes take place as the egg develops into a foetus.

At this stage, your dog's nipples may begin to change color and her breast tissue may begin to swell. She may also start leaking a milk-like fluid called colostrum from her nipples.

Your dog's weight may rise as her uterus expands to accommodate growing puppies. Make sure you measure her regularly to ensure she is growing at a healthy rate; losing weight could endanger either her health or that of any unborn puppies.

You may notice your pup is less interested in eating than usual. It's common for dogs to experience decreased appetite during this stage due to the discomfort and pressure from developing puppies, so if she's not getting enough food, try offering her several smaller meals throughout the day instead of two larger ones.

She may also become unwilling to eat for several days in a row or throw up occasionally, but these are not cause for alarm. However, if she starts refusing food more than three or four days consecutively, contact your veterinarian for advice and an examination.

At around this time of the month, your pup's nipples usually turn from light pinkish-gray to red or even rosy in color, especially the last four to six closest to her hind legs. This change is caused by increased blood flow to that area.

Your dog's nipples will appear more prominent and dark, and she might even leak some of her "first milk" from them. This is an encouraging sign that her fetus is developing properly.

As your dog's fetus develops, it may be appropriate for her to receive an ultrasound examination from your veterinarian. Ultrasounds detect fetal heartbeats and provide a safe and accurate way to confirm pregnancy.

The second trimester

In the second trimester of dog pregnancy, puppies begin to emerge. To ensure her safe delivery, it is essential for you to notice any changes in your pup as soon as possible.

It is also a good time to accustom her to being pregnant and begin to limit rough play or high-intensity exercise that could put your pup's unborn puppies at risk. While several short walks per day are acceptable during this period, be mindful not to push her into activities she feels uneasy with.

At the same time, you may start to spot the first signs of baby development in your dog's belly: rounded fetuses visible on ultrasound scans and mother's breast tissue swollen and her nipples becoming prominent and dark as they become engorged with milk (colostrum).

If you believe your dog may be pregnant, the easiest way to confirm it is with physical examination by palpation. This can be done between days 21 and 35 of gestation (three-to-four weeks) by your veterinarian using their hands and fingers.

When your vet performs a palpation on your dog, they can feel the fluid-filled sacs that form around the embryos inside her uterus. Additionally, they test for relaxin, which is only released during dog pregnancy.

As your dog's fetuses develop, their weight will begin to increase and they may feel much more uncomfortable. While her appetite should decrease during this period, she still requires plenty of calories in order to maintain herself and her puppies' health.

Monitor her weight regularly by measuring her and taking any changes seriously if needed. Your vet can check the state of her womb and treat any complications, and may suggest feeding her a higher protein diet or adding supplements to help with recovery from this illness.

The third trimester

In the third trimester of dog pregnancy, her uterus begins to expand. At this stage, she'll start eating smaller meals more frequently so it is essential that you feed her high-quality puppy food during this stage.

At this stage, you may notice your dog's nipples becoming enlarged; this indicates she's producing milk (lactation). She may also start to urinate more frequently than usual - a sign her body needs extra milk to help deliver its puppies safely.

At this stage, you may notice your dog is gaining weight. If she has been exceeding 10 percent of her normal weight, contact your veterinarian right away for advice on a diet to keep her healthy and strong during this time; however, do not start feeding her higher-calorie food until after the third trimester has ended.

As your dog enters her third trimester, you may notice fetal membranes (female reproductive organs). These are the first signs of growing puppies inside her belly; therefore, if you haven't already, take her to the vet now for further assessment.

At this stage, your vet can palpate your dog's uterus to check if she is pregnant. This should be done between days 25 and 28 of gestation and should only be done by an experienced professional.

Your veterinarian will be able to tell how many babies are on the way and if they are viable. They also know if a c-section is necessary, which is when your veterinarian extracts the puppies from your dog's uterus.

Once your vet confirms your dog is pregnant, they can arrange an ultrasound to detect the heartbeats of her puppies. Although this is a complicated procedure, it's the only way to confirm if her babies are healthy and ready to be born.

If your dog is in the last trimester of her pregnancy, expect her to give birth within a week or two. The delivery process can take up to 24 hours but it's possible the puppies could be delivered early - in which case, both your pup's lives and those of their unborn siblings could be put at risk.

The last trimester

In the final trimester of a dog's pregnancy, their belly will get significantly larger and you may even be able to spot puppies beginning their development inside her.

At this stage, your dog's mammary glands will begin to enlarge and produce milk for her growing puppies. You may also observe a small amount of fluid which may appear milky or reddish-brown in hue.

These changes in your dog's nutritional needs are completely normal and don't necessitate any adjustment in her diet. You can continue feeding her the same high-quality food she was on before pregnancy; there will be no need for additional supplements unless your vet has prescribed them.

In the third trimester of your dog's life, their bones and claws will continue to develop rapidly. They will also begin to harden.

Around day 30 on an ultrasound, you will be able to spot the heartbeats of the puppies. They should be approximately the size of walnuts and spaced evenly along their uterus (shaped like a letter V).

In the early stages of pregnancy, embryos move to a part of your dog's uterus known as a "horn." Here they become embedded within its lining and protected from external influences.

These horns look somewhat like the letter V and contain two halves of each embryo. By week three, all of the eggs will have been securely attached to their respective horns and spaced evenly throughout the uterus.

It is essential to avoid touching your dog's uterus during this trimester. Any kind of contact or pressure that does not belong to the mother can lead to complications in the puppies.

If your dog's uterus begins to bleed, this is an emergency and you should contact your veterinarian right away. Additionally, keep a close eye on her weight as this could also be indicative of an underlying issue.

The final trimester of dog pregnancy is an exciting and important time for both you and your pup! To prepare, set up a secure area away from foot traffic so that she can rest peacefully during her delivery. With this set up, it should be easier for both of you to feel safe as she brings her puppies into the world safely.