False pregnancy is also called phantom pregnancy or pseudocyesis. It is more common in dogs than in cats, according to veterinarian Debra Promivic. False pregnancy only happens to unspayed female cats. The only way to permanently cure a female cat of false pregnancy is to get her spayed, which removes her ovaries and uterus.
Cats with false pregnancy have swollen nipples and breasts, a much larger appetite than usual, and will look for a nesting site. This nesting site can be any warm place where the cat feels safe. The cat may also take toys and small objects, like washcloths or brushes, to the nest and curl up around them as if they are kittens. She may attack anyone that tries to take the "kittens" away. "Cat Owner's Home Veterinary Handbook" notes that, unlike dogs with false pregnancy, cats with false pregnancy usually do not produce milk.
Dr. Primovic notes that false pregnancy in cats is caused by a surge in hormones, including progesterone, that prepares the cat's body for pregnancy. Cats with hypothyroidism (an overactive thyroid gland) may trigger false pregnancies. VetInfo.com notes that females that mate with infertile male cats usually develop false pregnancy.
Symptoms of false pregnancy begin about five weeks after the cat stops her heat cycle. Symptoms usually disappear on their own in 30 to 40 days, according to "Cat Owner's Home Veterinary Handbook." If the cat does produce milk, even a little bit, the false pregnancy may go on longer than 40 days if the cat drinks her own milk in order to relieve any pain or pressure, according to Dr. Primovic.
Cats that were pregnant, but lose the kittens before the seventh week of pregnancy through spontaneous abortion or reabsorbing the foetuses, will show all of the signs of false pregnancy, according to "Cat Owner's Home Veterinary Handbook." These events happen often to cats with a lack of taurine in their diet or if the cats have been infected with feline leukaemia virus.
Although false pregnancy in cats is rare, cats that experience one false pregnancy are more likely to keep on developing false pregnancy unless they are spayed. Cats that were spayed while they were ovulating may go into false pregnancy once they recover from the anaesthesia, but they will never have another episode again.