Definition of False Pregnancy
False pregnancy, also called pseudopregnancy, is common in intact female dogs. It usually occurs somewhere between 6 and 12 weeks after a bitch goes through her normal heat cycle and is caused by an exaggerated response to normal hormonal changes, including elevated levels of the hormone progesterone. During this time, females can develop many of the signs of pregnancy, even if they arenâ€™t pregnant and havenâ€™t even been bred. Signs of false pregnancies include appetite fluxuations, restlessness, whining, depression, anxiety and aggression. Many bitches engage in maternal behaviours, such as digging, nesting and mothering of stuffed toys, and some actually produce milk. These signs can be so convincing that even experienced breeders are fooled. Fortunately, with the help of modern technology, false pregnancies are easy to diagnosis. They usually donâ€™t require treatment and go away on their own.
Symptoms of False Pregnancy
The clinical signs of pseudopregnancy range from subtle to extreme. In some cases, they are so convincing that even experienced breeders are confident that a litter is coming. Signs include behavioural changes (anorexia or appetite fluxuations, excessive vocalization, whining, restlessness, signs of aggression, depression, or anxiety), maternal behaviours (nesting, digging, mothering or â€œadoptingâ€ of toys, stuffed animals or other inanimate objects), mammary problems (engorgement, lactation, licking of the mammary glands/self-nursing), vomiting and abdominal distention.
There is no known age or breed predisposition for this condition, although some experts indicate that Dalmatians, Basset hounds and Pointers may be more frequently affected. Interestingly, the phenomenon of non-pregnant bitches developing milk and actually lactating may have had some functional importance in evolution, when mature canine bitches (such as wolves) without puppies had to nurse orphaned litters in the wild.
It is not difficult to diagnose false pregnancy in dogs. If the animal went through a heat cycle 6 to 12 weeks before the onset of clinical signs of pregnancy, whether or not she was known to be bred during that time, a veterinarian will take a thorough history of her recent physical and behavioural conduct and will perform a complete physical examination. Radiographs and ultrasound can be used to conclusively confirm the presence or absence of pregnancy, and no additional blood, urine or other tests should be necessary. Of course, since a dogâ€™s gestation period is only roughly two months, if 3 or more months have passed since the end of a bitchâ€™s previous heat cycle it is highly unlikely that she is truly pregnant.
Radiographs and ultrasound are also useful to rule out the possibility of a serious condition called â€œpyometra,â€ which is an accumulation of pus inside the uterus from bacterial infection. Pyometra can be life-threatening and must be treated as an emergency. It is uncommon, but still possible, that signs of false pregnancy will appear in a bitch who actually became pregnant and then either aborted or reabsorbed her puppies, in which case the risk of developing pyometra increases dramatically.