What Causes a Female Dog to Die During Pregnancy?

Female dogs are pregnant for 56 to 66 days before giving birth. Multiple complications can occur throughout the gestation period. Prenatal care is very important to the health of your dog and her puppies. Schedule a prenatal visit with your veterinarian two to three weeks after breeding; the vet can alert you to potential problems and give you instructions on how to care for your pregnant dog and her unborn puppies.

All dogs have parasites in their bodies at some point in their lives. However, most dogs develop immunity that keeps the parasite population to a minimum. This immunity can falter during pregnancy and activate the dormant larvae of parasite like ascarids, hookworms and threadworms in the female dog's tissues. The parasites can cause a range of problems, including serious infections and deadly diseases. Your veterinarian can test your pregnant female for parasites and may even be able to safely treat her with some medications.

There is always a chance your dog could lose her puppies while she is pregnant, and this sometimes contributes to the mother's death, too. Miscarriages, or spontaneous abortions, are caused by a number of things, including bacteria, fungi and parasites, but the most common cause is hormonal imbalance. A pregnant dog will usually recover after a miscarriage, life-threatening infection or internal hemorrhaging can occur if she is unable to expel the fetus, placenta or other pregnancy matter effectively on her own.

Canine distemper is a contagious and incurable viral illness that is often fatal to dogs. Nonimmune pregnant dogs who are exposed to distemper are at risk for serious illness or death, as are their puppies. The American Animal Hospital Association and other organizations typically discourage vaccination during pregnancy but say it is preferential to vaccinate even pregnant dogs when the risk of maternal, fetal and neonatal distemper is present. This is especially true in the case of shelter dogs when isolation isn't possible or the immunity of the dog is unknown.

Uterine inertia is a condition that sometimes happens at the end of a canine pregnancy when it is time to give birth. The problem occurs because the uterine muscles cannot contract and push the puppies from the uterus. Causes can include anything from obesity and lack or exercise to hormonal balance or oversize puppies. Uterine inertia can be fatal to the mother and puppies if medical assistance or surgical treatment is not given without delay.