Helpful Information on Pseudo-Pregnancies in Labradors

FALSE PREGNANCY IN THE LAB occurs when the dam produces both physical and psychological changes that are appear to show the dog is pregnant, but does not deliver any puppies. This can occasionally occur, the dam will often produce milk, engage in nesting activity and look like she’s pregnant. It’s amusingly sad to see the affected dog try to persuade a tennis shoe to nurse! These visible changes take place beginning about 4 weeks after the heat cycle begins (estrus) and can continue for a number of weeks. False pregnancies are always unpredictable and can show up whether or not a mating has occurred. Often so much milk is produced the bitch becomes uncomfortable. Once a dog has had a false pregnancy she’s likely to be afflicted again.

APPEARANCE
Most dogs experiencing a false pregnancy will begin to show some swelling in the mammary glands about five weeks after their heat cycle has ended. If you have bred your dam, you will be elated that she “is getting ready to have pups”. You might also be surprised that she “isn’t filling out much”. You will wonder why she isn’t starting to show a big belly. Many dogs whether they are bred or not, will develop a false pregnancy, and look, act, and even think as if they are pregnant. Some will carry small toys or pillows around and even start digging a nesting site wherever they please. When the time draws near to when they would be delivering the pups, usually 63 days after a mating, milk will drain on its own from the mammary glands. Some dogs are really troubled that they cannot find the pups they psychologically feel they should be nursing.

CAUSE OF FALSE PREGNANCY IN THE DOG
The exact hormonal mechanisms that must occur to trigger false pregnancy are as yet unknown. We do know that a combination of interacting hormones including estrogen, adrenal hormones, and prolactin from the pituitary gland influence milk production in the mammary glands. Prolactin levels seem to be the main culprit, but why this hormone does what it does when it shouldn’t is a subject for future research.

Fortunately 90% of false pregnancies resolve over a period of three weeks with no treatment. Since no real harm is done there’s no reason to speed up what nature will take care of in time. For about 10% of females, though, the psychological effects directing mothering behavior are so intense that the female is miserable. She’s continually searching for pups that aren’t there and seeking relief from the mammary gland engorgement that’s making her uncomfortable. Mastitis, an infection of the mammary glands, if it were to occur at this time could be particularly dangerous.

On occasion, in about 10% of false pregnancy cases, treatment is warranted. Various hormonal substances have been used to hasten the reabsorption of milk and to halt the milk production. None of these medications is entirely safe so close veterinary supervision is necessary. Most often the veterinarian will administer a hormone to interrupt the dog’s secretions of internal hormones that may be promoting the production of more milk.

BREEDING SOUNDNESS 
Any dog showing false pregnancy is apt to have a re-occurrence in the future. There is NO reason NOT to breed this bitch but it is possible she may be a poor producer. There seems to be a greater risk of pyometra, a severe infection of the uterus, in any female dog that has had false pregnancies. There’s no way of predicting the outcome of any breeding but many dogs that have had a false pregnancy have gone on to whelp normal, healthy litters. Evidence does not indicate that false pregnancies are an inherited disorder.