If your female dog is showing signs of pregnancy when she has not mated, you may be surprised to learn that this is actually a common occurrence in the canine world. False pregnancy in dogs presents with symptoms including nesting behavior, lactation, swelling of mammary glands, distended abdomen, and even signs like anxiety or loss of appetite. This condition mimics pregnancy in dogs that are not actually pregnant. There is no definite cause for false pregnancy, although it is common in intact (not spayed) dogs that have recently experienced a heat cycle and related to these hormonal changes that occur. When left untreated, false pregnancy usually resolves on its own within a few weeks, but veterinary care may be necessary in some cases that present severe symptoms.
What Is False Pregnancy in Dogs?
False pregnancy (pseudopregnancy) is a common condition of the reproductive system that causes signs of pregnancy in dogs that have not been spayed and are not actually pregnant.
To understand canine false pregnancy, it's important to learn how the female dog's reproductive system works. The heat cycle of female dogs has four stages:
- Proestrus: This is the start of the heat cycle when the body is preparing to mate. The vulva may swell, and there may be a bloody discharge. Hormone changes begin in this stage. Males will be drawn to the female (but the female will not yet be receptive to mating).
- Estrus: This is the mating stage. The female emits pheromones that attract males, and she becomes receptive to mating. Blood flow from the vulva decreases or stops. Ovulation occurs during this phase.
- Diestrus: During this stage, hormone changes prepare the body for pregnancy if mating has occurred. If there is no pregnancy, the hormones rebalance and the signs of estrus subside.
- Anestrus: This is a recovery phase where the reproductive system is inactive. No signs of heat are displayed at this time.
Female dogs naturally experience a hormonal state of pregnancy towards the end of the diestrus stage of the canine heat cycle. These changes prepare the body for pregnancy if she has mated. If she is not truly pregnant, the hormones should taper off within a week or two as the dog's body enters anestrus.
In some cases, the hormonal changes of diestrus can cause extreme symptoms or last too long. This is when false pregnancy occurs, as the female's body acts as if there is a real pregnancy when there is not.
Symptoms of False Pregnancy in Dogs
False pregnancy in dogs closely mimics an actual pregnancy—and thus, the symptoms are very similar. While physical symptoms may be easier to notice, owners may also observe behavioral changes in female dogs during a false pregnancy. The following signs are common:
Swelling of Mammary Glands
The mammary glands swell during a false pregnancy in the same way as during a true pregnancy. This is due to increased levels of hormones that do not decline normally.
As the mammary glands swell, lactation may begin. This can become uncomfortable for dogs. When milk production is excessive during a false pregnancy, your veterinarian may recommend treatments to reduce it. Do not touch or attempt to relieve milk from the glands; this can actually increase milk production and lead to further discomfort.
The abdomen may even appear distended as a result of false pregnancy. This is caused by fluid retention in the dog's body, which may make the dog appear to maintain its weight even during periods of minimal appetite.
Vomiting in dogs undergoing a false pregnancy is typically periodic. This may or may not lead to weight loss, and it's important for owners to prevent dehydration by ensuring the dog drinks plenty of water. Severe dehydration should be treated by a veterinarian with antibiotic fluids.
False pregnancy can cause female dogs to perform nesting behaviors similar to a true pregnancy. The dog may act as if she is about to whelp puppies (or as if she already has had puppies). She may begin attempting to "mother" inanimate objects during the nesting process.
Loss of Appetite
Pregnancy—both true and false—can change a female dog's appetite. The dog may stop eating or eat significantly less. Your veterinarian may recommend fluid treatments and supplements to balance your dog's nutrients until the false pregnancy resolves.
Similar to changes in appetite, false pregnancy can cause behavioral changes that include anxiety. This may be accompanied by restlessness or lethargy, and owners may even notice aggression if guarding behaviors develop.
Causes of False Pregnancy
There is no specific known cause for false pregnancy in dogs, however, it is believed that this condition is related to the hormone production that occurs after a dog's heat cycle.
Diagnosing False Pregnancy in Dogs
Contact your veterinarian if your female dog is showing signs of false pregnancy. Your vet will likely recommend that you bring the dog in for an exam to make sure she is not actually pregnant. Tests to confirm a canine pregnancy can be done around two to three weeks after conception, which may include bloodwork, X-rays, and ultrasounds. If you are not absolutely certain if your dog has mated, it's best to visit the vet about three weeks after the signs of estrus subside to determine whether pregnancy has occurred.
If your dog is not pregnant, your vet may recommend watching and waiting for a few weeks to see if the signs go away on their own. However, if the signs of false pregnancy are severe or prolonged, your vet may recommend various treatments. One option is the use of diuretics in an attempt to reduce the dog's milk production. Veterinarians may also administer a hormone treatment to slow milk production.
Tranquilizers may be recommended if behavioral changes are severe. Other hormones may be used to stop false pregnancy, but each case is unique. You and your veterinarian can work together to decide which treatments are best for your dog.
Prognosis for Dogs With False Pregnancy
Thankfully, false pregnancy often resolves on its own within one to three weeks (even without treatment). Your veterinarian may need to intervene if signs persist or are extreme, but many dogs do not experience significant issues. If your dog does experience more severe symptoms, veterinary attention can help relieve anxiety or any discomfort until the condition has cleared up naturally.
How to Prevent False Pregnancy
Since there is no known cause for false pregnancy, owners of intact female dogs cannot prevent this condition from developing if the dog will be bred in the future. However, any dog that is not intended for breeding can have its chances of false pregnancy limited through surgery.
The only permanent method of preventing false pregnancy in dogs is an ovariohysterectomy, which is commonly known as a spay surgery. Ovariohysterectomy is generally recommended for female dogs not suitable for breeding. However, dogs should not be spayed during the false pregnancy, as it may prolong the symptoms of the condition for several weeks. When deciding if you should spay your dog, keep in mind that the surgery should wait until all symptoms of false pregnancy have resolved.
False Pregnancy or Pseudopregnancy in Dogs. VCA Hospitals.
Reproductive Disorders of Female Dogs. Merck Manual Veterinary Manual.
Vomiting in Dogs. VCA Hospitals.
Singh, Kipjen L., et al. Canine pseudopregnancy and its treatment strategies. Journal of Entomology and Zoology Studies. 2018;6(3):1076-1078.