Dog: False Pregnancy

What is a false pregnancy?

False pregnancy (also known as pseudocyesis, phantom pregnancy or pseudopregnancy) is the term used to describe the condition whereby a non-pregnant dog undergoes bodily and behavioural changes similar to those you that would expect if she was pregnant. She may produce milk and start displaying nesting behaviour and in some cases she may guard objects such as toys or bedding as if they were her puppies. The condition results from the normal physiological changes that occur in an entire dog if she does not become pregnant after her season but can be exacerbated by changes in her environment and internal physiological sensitivities. On rare occasions false pregnancy signs can also occur in females which have been neutered, especially if surgery was performed during the phase of their sexual cycle when a low level of progesterone (a steroid hormone) naturally stimulates a surge of prolactin (the hormone that acts on the mammary glands to encourage milk production). False pregnancy can be prolonged if the dog is neutered whilst she shows signs of the condition, since the dog then potentially becomes fixed in this hormonal state because the necessary feedback mechanisms are no longer possible.

It has been estimated that as many as 75% of non-pregnant intact dogs may show some of the overt signs of false pregnancy, but they vary greatly in their severity.

What are the signs associated with pseudopregnancy?

Common initial behavioural changes may be lethargy and loss of sparkle. Later your dog may become more aloof and you may see nest building behaviour around the time you would expect her to whelp. She may start to collect stuffed toys, slippers and other objects and take them into her bed and begin guarding them. She may also show signs of being nervous and anxious at this time and may show aggressive behaviours, such as growling and snapping at anyone who approaches. It is important to recognise the cause of these behavioural changes and not respond punitively to your dog in the mistaken belief that she is being deliberately difficult or naughty. It is obviously also important to make sure that your dog is not genuinely pregnant.

Why does false preganancy occur?

In the wild, dogs often live in packs and frequently only the highest ranking female is allowed to breed and rear offspring. However, other females may be allowed to serve as nursemaids and help to rear the young. This might not only be of benefit if the two females are related but may also help the nurse to learn parenting skills so she becomes a better mother when she gets the opportunity to breed. In the domestic situation these dogs can also be used as very effective foster mothers if the mother of a litter has died or for some reason the pups have had to be removed.

What can be done?

False pregnancy is normally self-limiting and may require no treatment. Behaviour returns to normal once prolactin levels have fallen, but this can take some time and if behavioural changes are extreme, especially when aggressive displays are involved, intervention should be considered necessary. 

• When the mammary area is very swollen it can be tempting to milk the dog or to stroke the mammary area to ease the discomfort. This should be avoided as it can unintentionally continue the process and make the condition last for longer. Some authors report that it can help to wrap the dog’s belly to try to reduce her milk production but this can be difficult in a practical sense and dangerous if she is very protective and showing signs of aggression. 
• Medication is available from your veterinary surgeon which will help to resolve both the lactation and the behavioural signs of the condition. If there are overt behavioural signs you may need to use a slightly longer course of the medication but your veterinary surgeon will advise you.
• It is important to avoid any confrontational interaction with your dog and to remember that her behaviour is caused by anxiety and a feeling that she needs to defend herself.
• It can help to limit your dog’s access to items that she may chose to defend so try to remove toys and soft furnishing from the area that she is living in. Removing access to an established nesting area may be useful but it is important to assess every case on an individual basis and to avoid inducing problems of frustration in a dog that is highly motivated to nest. If you notice her starting to engage in nesting behaviour or gather up objects you can try to distract her away from this activity in a positive manner by offering an alternative activity such as a game or walk.
• It is important that your dog does not inadvertently learn to use aggression to resolve her anxiety about people or other dogs approaching her, as she may continue to use such behaviours once the false pregnancy has been resolved. It can therefore be beneficial to seek behavioural advice especially in cases where aggressive behaviour is a major feature of the false pregnancy.

Will it come back next time?

Many dogs have recurrent episodes of false pregnancy and it is therefore advisable to consider having such dogs neutered. It is very important that the surgery is carried out at the right time, so your vet may recommend a blood test first to ensure that her hormonal levels have returned to normal levels. Alternatively, they may suggest a course of medication prior to the surgery. If you have any questions about the implications of neutering and whether it is the correct course of action for your dog you should talk to your veterinary surgeon.