Phantom Pregnancy in Cats

Phantom pregnancy, also known as false pregnancy or pseudopregnancy, may occur in mature female cats. Cases of false pregnancy are very rare in felines. The cat presents all the signs and symptoms of a pregnancy without actually being pregnant.

Causes of Phantom Pregnancy

A false pregnancy may occur in cats after their heat cycle. The cat develops the symptoms of a pregnancy if she is bred by a tom cat that is infertile.

If the cat is bred, her body ovulates and produces a corpus luteum. A corpus luteum is a gland that is developed in the ovaries after ovulation. This gland produces progesterone, which may lead to typical pregnancy symptoms.

Once the corpus luteum is produced, the cat's body cannot make a distinction between pregnancy and non-pregnancy.

The phantom pregnancy may occur even in spayed cats, in case they were spayed during the diestrus stage of the reproductive cycle.

In very rare cases, cats with hypothyroidism can present symptoms of pregnancy without being pregnant, due to diverse blood changes.

Symptoms of False Pregnancy

The amounts of progesterone in the cat's body will cause changes that are similar to pregnancy symptoms:

  • Swollen nipples and larger mammary glands
  • Pink nipples
  • Vomiting
  • Weight gain
  • Swollen abdomen
  • Lack of heat cycle
  • Extremely affectionate behavior
  • Production of milk

The cat will start building a nest when preparing for delivery. These symptoms will occur within 6 to 12 weeks after the cat's last heat cycle.

Determining a False Pregnancy

If you notice some of these pregnancy symptoms, the easiest way to determine if the cat is really pregnant is by visiting the vet. You may also palpate the cat's abdomen after 5 weeks of "pregnancy"; if you can feel any lumps, your cat is pregnant. The lumps should increase in size if you are dealing with a real pregnancy. In the last stages of the gestation you may even notice the kittens moving inside your cat's abdomen.

Dealing with a Cat with Phantom Pregnancy

In case your cat displays signs of phantom pregnancy, you need to treat her normally. If she is seeking more attention, give it to her. All you can do is wait until the cat gets over her false pregnancy behavior. The symptoms of pseudopregnancy may persist for several months.


The incidence of phantom pregnancies in cats is very low, as the chances of a female cat being bred by an infertile tom cat are minimal. Dogs develop false pregnancy symptoms more often, as after a heat cycle dogs may ovulate and produce a corpus luteum even if they are not bred.