Pregnancy Termination for Dogs

By Betty Lewis

For a dog in heat and her male suitor, the time is always right for love. For her owner, maybe not so much. It may be that you had plans to breed your lady pup or maybe you didn't get her spayed in time, but the bottom line is you're not ready for puppies. Your vet can work with you to terminate her pregnancy.

Mating Doesn't Always Mean Pregnancy

Before you worry about terminating your dog's pregnancy, you'll need to confirm she is pregnant. Just because she had an intimate moment doesn't mean she conceived. According to the Merck Veterinary Manual, 60 percent of misbred dogs don't conceive. The vet can confirm a pregnancy around 20 to 22 days after breeding with abdominal ultrasound and palpation. The earlier you can confirm pregnancy the better; attempting to terminate after 40 days carries the potential trauma of delivering puppies anyway. The vet can use a test, similar to a home pregnancy test, about 30 days after mating to confirm pregnancy.

Spaying During Pregnancy

If you planned to spay your dog, spaying her and and aborting the embryos will terminate her pregnancy and ensure she doesn't become pregnant again. Normal spay surgery entails removing her uterus and ovaries; if she's pregnant, the embryos are taken with the uterus. For the dog who's not going to be bred, this is usually the best option, though it does have a few risks. The reproductive tract's blood vessels are more difficult to tie off when a dog's pregnant, making the surgery longer and more expensive. As well, recuperation time takes a bit longer than a routine spay.

Prostaglandins and Glucocorticoids

There are three types of medication available to terminate a dog's pregnancy without sterilizing her: estrogens, prostaglandins and glucocorticoids. The vet will determine the best option, based on your dog's health and where she is in her pregnancy. Prostaglandins reduce the level of progesterone to terminate the pregnancy. Pyometra, a uterine infection, is the most serious potential side effect of prostaglandins. Your dog should stay at the vet for her treatment, which will last four to seven days. Prostaglandins don't always work and sometimes only a portion of the litter is aborted, so ultrasound is necessary to confirm the entire pregnancy has been aborted. Glucocorticoids are often used for late stages of pregnancies and aren't always effective. Since these drugs are used in late stages of pregnancy, the dog often delivers dead puppies, which can be traumatic for her. Since a high dose is necessary, common side effects include increased thirst and urination, as well as panting and occasional incontinence.

The Problems with Estrogen

Estrogen is still an option but it's rarely used because it's not very effective and carries a risk of causing pyometra. Other potential side effects from estrogen include bone marrow suppression and an extended state of estrus. Estrogen is only for the earliest stage of pregnancy -- when it's too early to confirm her condition -- and works by preventing fertilized eggs from implanting in the uterus. Since the risk of side effects is so significant and there's no way to confirm the pregnancy, many vets won't use this method as it potentially puts the dog at risk for no reason.

Myths Vs. Facts

If your dog had an unwanted romantic encounter, a post-coital douche won't terminate her pregnancy. The only thing you can do is wait it out until the vet can confirm your suspicions. In the meantime, keep her contained while she's in heat so she can't entertain any more male suitors. If you've been planning to spay her, talk to the vet to make an appointment after she is out of heat. If you decide to go ahead and become a grandparent, be prepared for the prenatal and post-delivery care you'll have to take on, as well as finding good, responsible homes for the puppies. If your dog does have an abortion, talk to the vet to learn what behavior to look out for while your dog is in recovery.