False Pregnancy in Female Dogs

Key takeaways

False pregnancy is a very common condition where female dogs produce hormones which prepare them for pregnancy, regardless of whether they actually mate.

  • This leads to symptoms which mimic pregnancy, including weight gain, lactation, and behavioral changes such as nesting, lethargy, and aggression
  • Diagnostics including bloodwork and diagnostic imaging help determine whether a dog is actually pregnant
  • False pregnancies pass on their own, usually within two months, although medication may be indicated to reduce symptoms
  • Spaying an animal prevents false pregnancies from reoccurring
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A closer look: False Pregnancy in Female Dogs

A dog’s reproductive cycle occurs once or twice per year, and has multiple stages. During the proestrus a dog’s vulva enlarges and excretes a bloody discharge. Female dogs become attractive to males during this phase. During the estrus stage, vulval discharge becomes straw-colored, and females allow males to mount.

Diestrus is the third phase, during which hormones prepare the dog for pregnancy. In pregnant dogs, hormonal production continues for the duration of the gestation period. Otherwise, production tapers off within two months, returning the dog to the beginning of their cycle.

It is during the diestrus phase that a dog may appear to be pregnant- a ‘false pregnancy.’ False pregnancies may have had an evolutionary advantage during pack lifestyle, as nonpregnant females would be available to nurse the puppies of pregnant females.

False pregnancies are very common. While symptoms may be initially alarming or surprising, they represent a normal part of a dog’s reproductive cycle and are not cause for medical concern.

Dogs showing symptoms of false pregnancy benefit from veterinary attention to determine whether a pet is actually pregnant, and establish next steps and management.

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Risk factors

Alongside physical changes, pregnancy also brings about behavioral changes, including:

  • Nesting behavior
  • Aggression
  • ‘Mothering’ of objects or other animals

Lactating dogs have a risk of developing mastitis. Monitoring symptomatic dogs for signs of heat, pain, or abnormal discharge allows for timely veterinary intervention.

Possible causes

The underlying trigger for developing false pregnancy is often unknown, but can occur in any nonpregnant female during the diestrus phase of her cycle.

False pregnancy can also occur if a female is spayed during diestrus.

Main symptoms

Symptoms of false pregnancy are similar to normal pregnancies.

Testing and diagnosis

Diagnostics include:

  • A physical examination
  • Bloodwork, including measuring progesterone levels
  • Diagnostic imaging, such as ultrasound or X-rays to determine pregnancy status

Steps to Recovery

A false pregnancy is a normal part of a dog’s reproductive cycle, and does not require a “cure.”

When indicated, treatment reduces symptoms until the diestrus period naturally passes. This may include:

  • Icing mammary glands to reduce their activity
  • Increased exercise, to reduce energy available for lactation
  • Changes to the diet
  • Hormone-reducing medication

A spaying operation prevents false pregnancies, but does not halt symptoms if the surgery occurs during the diestrus period.

A false pregnancy lasts 4-6 weeks, and typically passes on its own. An unspayed dog goes through their reproductive cycle once or twice per year, although cycling becomes less regular as they age.

False pregnancies do not have any impact on a dog’s future fertility.


Spayed dogs do not go through a reproductive cycle, preventing future false pregnancies.

False pregnancy is not contagious.

Is False Pregnancy in Female Dogs common?

False pregnancies are very common.

Typical Treatment

  • Medication
  • Exercise
  • Dietary changes


Wendy Brooks, DVM, DABVP - Writing for Veterinary Partner
Malcolm Weir, DVM, MSc, MPH; Ernest Ward, DVM - Writing for VCA Animal Hospitals
Purina Pro Plan - Writing for The American Kennel Club
Clare M. Scully , MA, DVM, MS, DACT - Writing for Merck Veterinary Manual

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