Phantom pregnancy in dogs: symptoms and causes

Phantom pregnancies in dogs are very common, with symptoms from mothering behaviour and lactation, to lethargy and vomiting. Find out more about signs, causes and possible treatment.
dog on a couch with a toy
dog on a couch with a toy
dog on a couch with a toy

Has your dog started acting like they are pregnant, mothering their toys and creating a nesting space? Have you noticed mammary development and even milk from their nipples? Some female dogs may display signs equivalent to morning sickness; with lethargy and vomiting. If your dog has not been mated, this may leave you scratching your head as to why they appear pregnant. If they have been mated, before you get too excited about visions of cute puppies, you need to make sure it’s not a false or phantom pregnancy.

Read on to discover what the signs are, how a false pregnancy gets diagnosed and when medical treatment is necessary.

What is phantom pregnancy in dogs?

Phantom pregnancy in dogs refers to a condition where a female dog exhibits symptoms of pregnancy, but is not actually pregnant. This is also known as false pregnancy or pseudo-pregnancy and can affect any type of female dog, regardless of age or breed.

Symptoms of phantom pregnancy in dogs

You can expect to see many of the same symptoms of an actual pregnancy to manifest in the case of a false pregnancy. Although the signs vary between individuals, these are the main physiological and behavioural changes to look out for:

  • Mammary development

  • Lactation

  • Enlarged belly

  • Loss of appetite

  • Lethargy

  • Vomiting

  • Nesting

  • Being protective of small inanimate objects

  • Restlessness or aggression

How long does a phantom pregnancy last?

The symptoms of a phantom pregnancy most commonly occur 6-8 weeks after your dog finishes her season, and should resolve within 2-3 weeks. Once your dog has had a false pregnancy after a season, it is very likely to recur at each subsequent season.

What causes phantom pregnancy in dogs?

The origins of phantom pregnancy are thought to be due to the pack behaviour of our domestic dog’s ancestors. All the females in the pack help to rear the family pups and feel motherly towards them, even when they are not their own offspring. This cooperative behaviour is driven by hormones. After a female dog has a season, she experiences a prolonged peak of the ‘pregnancy hormone’ progesterone lasting 8-9 weeks, whether she is pregnant or not (this does not occur in humans). As levels of progesterone decline levels of a second hormone, prolactin, increase.  This is what triggers the physical and psychological symptoms of pregnancy. In some dogs this may be mild – not enough to notice – but in others the symptoms can be very convincing to both the dog and her owner.

What to do when the phantom pregnancy symptoms appear

Phantom pregnancy in dogs is very common and, if symptoms are behavioural and mild, you can try distracting your dog with increased play and walks. While they’re distracted you can remove any toys they have adopted as surrogate babies, being careful not to cause distress. You should make an appointment with your vet if the symptoms persist or are severe. Remember that non-specific signs such as vomiting and lethargy may also be due to other diseases and illnesses. It’s also important to rule out a true pregnancy as your dog may have had an illicit mating!

How is false pregnancy in dogs diagnosed?

To diagnose false pregnancy your vet will take a history about your dog’s recent seasons and any matings. They will examine your dog for abdominal swelling, mammary growth and lactation. They may advise ultrasound or x-rays to check whether puppies are present.

Is there a treatment for phantom pregnancy in dogs?

Mild symptoms can usually be managed by distracting your dog from nesting and mothering. In more persistent or severe cases, the vet might recommend a treatment to help restore the hormonal balance. You should also consider discussing with the vet about spaying your female dog after the false pregnancy has subsided, to prevent recurrence.

dog being checked at the vet

Is spaying a good solution for phantom pregnancies in dogs?

Spaying (ovariectomy or ovariohysterectomy) is a long-term solution that will prevent future episodes of phantom pregnancy. However, a dog should not be spayed during a phantom pregnancy as this can cause the symptoms to persist. The changes that occur to the womb during phantom pregnancies increase the risk of uterine infection (pyometra), which can be life-threatening. If your dog has phantom pregnancies and you are not planning to mate from her, it is advisable to have her spayed to reduce this risk. Other benefits of spaying include reduced risk of developing mastitis, mammary, uterine or ovarian cancer, and removing the possibility of unplanned pregnancies.

Discover more about puppy neutering and spaying from our in-depth article, such as what does the process involve, recovery tips as well as what changes to expect.