If your cat was bred accidentally, there are alternatives to having an unwanted litter. If you were planning to have your female spayed, as mentioned before, your veterinarian will usually go ahead with the surgery.
Usually this is the best and safest step to take. Particularly in the early stages of pregnancy, surgery is not much more difficult than for a female in heat and the fee may be the same. In the later stages of pregnancy the surgery becomes more difficult and the fee usually increases accordingly.
If you have not yet decided on the question of spaying, and if you can get your cat to a veterinarian soon after breeding (within the first twenty-four hours or so, assuming you know your cat has been bred), injections of an estrogenlike compound can be used to prevent pregnancy. The compounds used for this purpose work by preventing implantation of the fertilized ova into their “beds” in the uterine wall. These drugs should be used to prevent pregnancy only if you are unwilling to choose another alternative and are willing to accept possible side effects. Their use in cats is not usually recommended by veterinarians since they may cause uterine changes leading to infection or death of the bone marrow (followed by death of the patient), and most owners cannot be sure when breeding has actually occurred.
Some drugs will induce abortion in cats. Ask your veterinarian for information if you think your cat needs such treatment. A surgical abortion can be performed late in pregnancy if absolutely necessary. Methods similar to those used in humans are not used in cats. Surgical abortions in cats consist of cesarean sections in which the kittens are removed through uterine and abdominal incisions. This procedure usually results in blood loss, is stressful on the female, and is not encouraged by most veterinarians.