A phantom (false) pregnancy is the term used when a bitch is not pregnant but shows signs of pregnancy, lactation, nursing and nesting. Phantom pregnancies are not uncommon. Some figures show that up to 60% of bitches experience them to some extent during their life time.
An intact female dog will experience changes in their reproductive hormones during their natural oestrus cycle. Individual dogs vary in the length of time between seasons, and this is to some extent inherited from the mother. The text book period of time from one season to the next is 6 months.
Phantom pregnancy is commonly thought to be a natural phenomenon, dating from the days of when dogs lived in packs. All bitches in the pack would come into season together even though only the alpha (dominant) bitch would mate. The alpha female’s pups would be cared for and suckled by the rest of the females in the pack. Pseudopregnancy (phantom pregnancy) made this possible as all the other bitches would have milk to give to the alpha female’s offspring.
Some owners wonder if mating their bitch will stop the occurrence of phantom pregnancies but the opposite has been shown to be true. Bitches who have whelped may in fact be more likely to have phantom pregnancies.