False pregnancy, phantom pregnancy, pseudo-pregnancy or pseudocyesis can be
defined as a display of maternal behavior together with the physical signs of
pregnancy following estrus (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 estrus The severity
of the clinical signs also varies between individuals and from one occurrence
to the next within the same individual.
Behavioral 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 estrus 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.
Mild cases are frequently not treated by the veterinary surgeon and will subside
of their own accord in approximately 14-21 days.
However in some cases where the bitch appears physically ill or the behavioral
changes are of such magnitude as to cause concern, treatment has to be instituted.
This can range from mild tranquilization 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, (spaying
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 neutered. Should this
occur treatment with a single injection of an hormone will usually suffice to
bring about improvement.
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