Mild cases of false pregnancy are a fairly common condition in which a non- pregnant bitch acts as if she were pregnant. The condition is caused by progesterone, which is manufactured by corpora luteal cysts in the ovaries. Signs appear about six to eight weeks after estrus.
A bitch with full-blown pseudopregnancy may exhibit some or all of the physical and behavioral signs of a true pregnancy, including abdominal distension, enlargement of the mammary glands, and even lactation. Some females make a nest and become attached to small toys and other puppy substitutes, occasionally guarding them aggressively. Bitches may vomit off and on and become depressed; a few develop diarrhea. The mammary glands may become caked and can be painful.
Treatment: Most cases do not require treatment. Pseudocyesis disappears spontaneously in 12 weeks or less. Bitches with aggressive behavior or severe symptoms can be treated with hormones such as Ovaban or prolactin inhibitors. These drugs have significant side effects and are therefore not routinely used.
A female with pseudocyesis is likely to have other false pregnancies. If breeding is not intended, she should be spayed. This should be done after the pseudocyesis resolves.