Estrogen injections should not be recommended by the veterinarian. While this was once a common treatment, the doses used can have a serious and sometimes fatal effect on dogs. The levels of estrogen used predispose the dog to a urinary tract infection called pyometra that can be fatal. The injection may cause suppression of bone marrow. The effectiveness of the estrogen injections is also doubtful as many of the dogs who were administered this treatment were probably not pregnant in the first place.
An unwanted dog pregnancy (or "mismating," as it is called in veterinary practice) can be ended in a number of ways. A vet must verify the dog is pregnant before a termination is considered as many dogs who are brought in to end mismate pregnancies are not actually gestating. It is important to bring a dog to the vet as soon as possible to end the pregnancy as a dog's gestation period (length of pregnancy) is only nine weeks and late-term abortions are often unreliable and distressing for the dog and owners.
Get the dog spayed if you do not plan on breeding her in the future or if she is not healthy enough to give birth. Spaying (ovariohysterectomy) is one of the safest ways to terminate a dog pregnancy and is not likely to have long-term side effects. As the pregnancy advances, the risk to the dog's health becomes greater. During spaying, the developing fetuses are removed with the uterus. The ovaries are also removed.
Giving the dog prostaglandins to inhibit progesterone in the pregnancy. Progesterone is vital to maintaining pregnancy so blocking it will terminate the dog fetuses. Prostaglandin F2 alpha, which is commonly used in canine abortions, can cause bad side effects for the dog such as vomiting, diarrhea, nausea and trembling. Because of its side effects and because of the risk it poses to pregnant women and asthmatics, this treatment must be administered in a veterinary clinic. The drug has to be administered twice daily: for four days in the first half of pregnancy or until abortion occurs in the second half.
Injecting a dog with dexamethasone will also end a pregnancy. Dexamethasone is advantageous as it does not require hospitalization of the bitch and is completed over a course of 9 to 12 days. Depending on how far along the dog is in gestation, the unborn pups will be either reabsorbed or aborted. Because of the high doses used, side effects such as frequent urination, strong thirst and panting may occur.
- Labrador retriever litter image by crazy.nataly from Fotolia.com