Phantom Pregnancy
False pregnancy, phantom pregnancy, pseudo-pregnancy or pseudocyesis can be defined as a display of maternal behaviour together with the physical signs of pregnancy following oestrus (heat) in a non-pregnant bitch. The bitch may or may not have been mated.
Many bitches show signs of pseudo pregnancy. It usually begins 4-9 weeks after the previous heat period. The signs range from mammary development with or without the production of milk, lassitude, loss of appetite and sometimes vomiting. Signs can occur at any age and do not necessarily follow every oestrus. The severity of the clinical signs also varies between individuals and from one occurrence to the next within the same individual.
Behavioural changes include nesting, mothering activity, restlessness, disinclination to exercise and sometimes aggression due to a perceived threat to an impending family. The bitch is often off her food but surprisingly seldom appears to lose weight, probably due to the amount of excess fluid she is carrying.
The hormonal changes the bitch undergoes following oestrus are similar whether she is pregnant or not. Changing levels in circulating hormones in the pregnant and pseudo pregnant animal are accentuated and the reason that this occurs in an animal that has not conceived is poorly understood.
"The hormonal changes the bitch undergoes following oestrus are similar whether she is pregnant or not."
Mild cases are frequently not treated by the veterinarian and will subside of their own accord in approximately 14-21 days.
However in some cases where the bitch appears physically ill or the behavioural changes are of such magnitude as to cause concern, treatment has to be instituted. This can range from mild tranquillisation and treatment with diuretics in order to reduce the milk production to hormonal treatment.
If the bitch is not to be used for breeding, ovariohysterectomy, (speying or neutering), should be considered.
If neutering is carried out while the bitch is showing signs of pseudo pregnancy or alternatively has been receiving hormonal treatment the signs will often persist for several weeks despite the fact she has been speyed. Should this occur treatment with a single injection of a hormone will usually suffice to bring about improvement.
© Copyright 2025 LifeLearn Inc. Used and/or modified with permission under license. This content written by LifeLearn Animal Health (LifeLearn Inc.) is licensed to this practice for the personal use of our clients. Any copying, printing or further distribution is prohibited without the express written consent of LifeLearn. This content does not contain all available information for any referenced medications and has not been reviewed by the FDA Center for Veterinary Medicine, or Health Canada Veterinary Drugs Directorate. This content may help answer commonly asked questions, but is not a substitute for medical advice, or a proper consultation and/or clinical examination of your pet by a veterinarian. Please contact your veterinarian if you have any questions or concerns about your pet’s health. Last updated on Nov 17, 2016.
