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Canine False Pregnancy

Issue Description
Pseudocyesis is the medical term for a false pregnancy. Pseudocyesis can cause many of the signs and symptoms of pregnancy, and often resembles the condition in every way except for the presence of a fetus.
Other Names
Pseudocyesis, Phantom Pregnancy, False Pregnancy

Dogs become pseudopregnant following an estrus phase in which the female dog is not bred, or in which it is bred by an infertile male. Most species require signals from an embryo (such as IFN-�„ in ruminants) to alert the female's body of a pregnancy. This maternal recognition of pregnancy will cause persistence of the corpus luteum and the development of characteristics and behaviors necessary to care for offspring. Limited research suggests that progesterone secretion is similar in pregnant and non-pregnant bitches, so veterinary researchers hypothesize that dogs may not require molecular factors from the embryo for maternal recognition of pregnancy, and instead the corpus luteum persists regardless of pregnancy. Since the corpus luteum is not degraded, it will cause the development of maternal characteristics in the absence of pregnancy. Pseudopregnant bitches will develop their mammary glands, lactate, and build nests to varying degrees depending on breed. Although bitches usually only cycle once (monestrous bitches) or twice (diestrous bitches) per year, pseudopregnancy in dogs is common because the bitch does not have to be bred to become pseudopregnant.

Many dogs whether they are bred or not, will develop a false pregnancy, and look, act, and even think as if they are pregnant. Some will carry small toys or pillows around and even start digging a nesting site wherever they please. When it is about the same time in which they would be delivering the puppies, usually 63 days after a mating, milk will come out on its own from the mammary glands. Some dogs become distressed because they cannot find the puppies they psychologically feel they should be nursing.

The diagnosis of false pregnancy is made by a history of a heat cycle (estrus) within the preceding 2 to 3 months of presentation to the veterinarian and the clinical signs of pregnancy. A physical examination will be done; the veterinarian will feel the abdomen (palpation). The veterinarian may want to take radiographs (X-rays) or perform ultrasound (visualization of deep body structures by ultrasonic waves) to rule out normal pregnancy or infection of the uterus as a cause of the signs.

In most animals, no treatment is necessary, because the affected female will "cycle" out of the false pregnancy on her own. This may take as long as 2 months. Surgical removal of the ovaries and uterus (spaying) may be advisable in females that have severe or repeated false pregnancies. If your pet's mammary glands become large and painful, application of alternating warm and cold compresses 3 to 4 times daily usually relieves the discomfort. You can also feed one half the normal amount of food for 2 days to reduce milk production. If she is still having pain after 2 days, contact your veterinarian. Also notify your veterinarian if there is discharge of blood or fluid from your pet's vagina or if she is depressed for more than 2 days.

Spay During False Pregnancy
It might seem like a good idea to spay the female to end the false pregnancy as spaying will remove the ovaries and the corpora lutea they carry. Unfortunately, this does not end the prolactin production from the pituitary gland so spaying may actually prolong the false pregnancy. It is best to wait until the false pregnancy is over and then spay her to prevent future episodes.

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