How to Determine if Your Dog is Pregnant

If your female dog mates with a male dog and neither of them has been spayed or neutered, it's highly probable she will become pregnant. However, mating alone does not guarantee pregnancy, particularly if the mating does not align with her ovulation cycle. So, if your female dog has mated, how can you confirm if she is pregnant? Here are ways to determine whether your dog is in heat or pregnant.

Check if the Dog Has Been Spayed If you've had the dog since she was a puppy, you should know whether or not she has been spayed (or had her ovaries removed). However, if you adopted her from a rescue center, you may not be certain. A dog that hasn't been spayed will go into heat twice a year, so if you've had her for over 9 months and she hasn’t shown signs of being in heat, it’s likely she has been spayed.

• The duration of heat varies by dog, but it typically lasts about 18 days. Dogs usually go into heat between 6 and 24 months of age.
• Read the following steps to identify signs of heat.

Look for abnormal signs at the vaginal area. When a dog is in heat, you may notice changes in her vaginal area.

• Swollen vulva: The external vaginal area will swell for about 4 weeks, starting shortly before the heat period and continuing until it's over.
• Vaginal discharge: During the first 7-10 days of heat, the female dog may have slight bleeding. You can place a white towel where she rests and check for blood spots. If your dog is meticulous, she will lick up the blood, making any spots hard to see. The discharge will decrease around the middle of the heat cycle (this is when the dog is ovulating and may become pregnant) and will intensify again in the last 7-10 days of the cycle.

Observe changes in behavior. When a dog is in heat, hormonal changes will lead to behavioral shifts. These changes vary depending on the dog's personality. If your dog is normally calm, she may become more irritable and agitated, or if she’s typically docile and stays at home, she might try to escape and wander off.

• In addition to these changes, your dog should maintain her health. If she appears lethargic, loses her appetite, vomits, or drinks excessively, contact the vet immediately. Uterine problems (like a pyometra infection) can cause symptoms similar to those of heat and may pose a serious risk to the dog’s life if left untreated.

Remember if your dog mated with a male dog. Clearly, for a dog to become pregnant, she must mate with a male. Think back to whether she mated with any male dogs, or if she managed to escape and wander off with one during her heat cycle?

Check if the male dog has been neutered. A neutered male dog can still mate but will not produce sperm necessary for conception. Only an intact male dog can impregnate a female. If possible, contact the male dog's owner to confirm.

• An exception would be if the dog was recently neutered, within 4 weeks of mating. In this case, sperm may still be present in the ducts and released during mating. While the likelihood is low, it cannot be completely ruled out.

Record the date of mating. This step helps you track important information about the likelihood of pregnancy. If the mating took place 3 months ago, it’s too late for the dog to be pregnant. The average pregnancy duration for dogs is 62-65 days (ranging from 57-72 days). If your dog were pregnant, she would have given birth by day 90.

Record the date of the dog's heat cycle. This helps the veterinarian determine the best method for pregnancy testing. Diagnostic methods for pregnancy are based on identifying hormonal changes, physical signs, or detecting the embryo in the uterus. The choice of method depends on the mating date.

• If the female dog has mated but has not yet finished her heat cycle, it’s still too early to determine if she’s pregnant.

Watch for lethargy and other behavioral changes. Many dog owners notice changes in their dog’s behavior during pregnancy: becoming sleepier, more sluggish, and starting to nest. However, these can also be signs of a false pregnancy, where the dog behaves as if she's pregnant but isn't. Some dogs with false pregnancies even produce milk, so enlarged mammary glands are not a reliable indicator of actual pregnancy.

Notice the development of the dog's nipples. One of the more reliable signs of pregnancy is when the dog's nipples grow larger. They will typically become larger and take on a pinkish color.

• A pregnant dog won’t produce milk until late in her pregnancy (or sometimes after giving birth).
• It’s important to take your dog to the vet for a proper pregnancy test. Pink nipples for 4 weeks or even a few weeks after mating is a suspicious (but not conclusive) sign of pregnancy.

Watch for a growing waistline. Similar to humans, a gradually expanding belly is a red flag during pregnancy – but this should be monitored carefully. For a healthy, well-balanced dog, you may not notice any significant changes until day 50-55 of the pregnancy, when the uterus has grown enough to push the belly outward.

• Your dog does not need extra calories until the third trimester (after 40 days). If you suspect she is pregnant and start increasing her calorie intake, she might gain weight, but it could be fat, not puppies.

Understand the concept of false pregnancy. If your dog is having trouble carrying a pregnancy, you might need to assist her; however, it's possible that she’s not actually pregnant but is experiencing a false pregnancy along with a pyometra infection. False pregnancy (typically caused by hormonal imbalance) isn't life-threatening, but pyometra is a serious concern. If left untreated, the uterus can fill with pus, leading to blood poisoning, organ failure, and death.

• Symptoms of pyometra may resemble those of pregnancy, such as a bloated belly and lethargy. However, pyometra also causes a loss of appetite and increased thirst. If your dog shows these signs, call your vet immediately.

Palpate the dog’s abdomen for initial signs. Vets will first palpate the dog’s abdomen to detect the presence of puppies. This can only be done at least 21 days after mating. If the exam is done too soon, the vet will only feel the enlarged, thickened uterus, but no puppies yet (the embryos are still tiny, like jelly pieces at this stage).

• The ideal time for manual palpation is day 28 of the pregnancy. At this point, the puppies are large enough to ‘kick’ the uterus, and it will feel like touching a string of beads.
• By day 35, each puppy is surrounded by its own amniotic sac, and the vet will be able to feel the long, sausage-like fluid sacs in the uterus.

Be aware that manual pregnancy testing can be inaccurate. Remember, on day 28, the vet can only feel small lumps, around 25mm in size, which are difficult to differentiate from food or feces in the intestines. Also, if the dog is tense or stiff, it will be hard to detect anything – it’s like trying to see through a window that’s been painted shut. Similarly, the puppies could be mistaken for other organs such as the bladder, kidneys, or even feces.

• Don't be disappointed if the vet suggests another method of testing when manual palpation doesn’t provide a clear result.

Blood test after 28 days. A blood test is used to measure the levels of pregnancy hormones. For accurate results, the test should be performed after day 28. Testing earlier can lead to false positives, as high hormone levels might be caused by the slow breakdown of hormones during the estrus cycle. However, after day 28, the pregnancy hormone levels will confirm if the dog is pregnant.

Get an ultrasound to detect pregnancy early. Ultrasound is a common method for determining pregnancy, as a skilled vet can detect even small changes in the uterus as early as day 18. Another advantage is that the vet can also determine the number of puppies in the litter, which helps the owner monitor the birth process.

• Embryos can be seen from day 18, and by day 28, a heartbeat can be heard.
• Note that ultrasound is a non-invasive procedure performed while the dog is awake. The ultrasound device directs high-frequency sound waves at the uterus, and the reflected sound creates an image. This is considered a safe procedure. The fur on the dog’s abdomen will need to be trimmed for the probe to make contact with the skin.

Understand why X-rays are not recommended. Most ultrasound methods have replaced X-rays for pregnancy diagnosis in dogs. X-rays are typically only used once the puppies have developed bones, usually after day 49, which delays the diagnosis. From a safety perspective, while the radiation doesn’t harm the puppies, the mother dog must be sedated during the procedure. According to health and safety regulations, the operator must leave the room when the X-ray is in use. Since dogs, especially later in pregnancy, often cannot remain still when left alone, the only option is to sedate them.

• Sedating a pregnant dog is strongly discouraged due to the risk of low blood pressure in the puppies. For these reasons, X-rays are no longer commonly used in pregnancy diagnosis.