It's heartbreaking if puppies in a litter are born dead, but it's also important to find out why it happened. The reason affects the future breeding health of your dog and possibly surviving littermates. Getting to the bottom of the problem requires veterinary testing of the mother and a necropsy of the dead puppies. The vet should also examine any surviving puppies. Avoid potential heartbreak by having the female dog thoroughly examined before pregnancy and issued a clean bill of health.
Dystocia is the term used for difficulties during delivery. Common causes of dystocia include oversize puppies stuck in the birth canal, abnormalities of the vagina or vulva, and uterine infection. If labor is prolonged, veterinary intervention is necessary to save the puppies and the mother. Bring the mother and any surviving puppies to an emergency veterinary hospital.
For a successful pregnancy, the mother should be in good condition. A pregnant dog who doesn't receive sufficient food, or who is in poor physical condition, can easily lose her puppies. Older dogs, even those in good condition, are predisposed to having puppies develop abnormally in the womb and die.
Brucellosis in Dogs
If a pregnant dog carries the bacterium Brucella canis, she will generally abort the puppies late in the pregnancy. Sometimes, the mother might actually deliver the puppies, but they are stillborn. Any puppies born alive die a short time later. There's no cure for brucellosis, which affects both male and female canine reproductive organs. Infected dogs are often asymptomatic, so have the vet conduct a blood test for these bacteria before breeding. The mother should be spayed, as she'll never deliver a live litter.
Certain canine viruses can cause fetal death, including the herpes virus, parvovirus, adenovirus, coronavirus and the distemper virus. Bacterial culprits include E. coli, streptococcus and staphylococcus. The protozoal parasite Neospora caninum infects the brain and spinal cord of fetuses and newborns, eventually killing them. In most cases, the mother shows no signs of illness.
Genetic and Physical Defects
Fetuses with genetic or physical defects, such as abnormal organ development or chromosomal abnormalities, will likely die in utero or shortly after birth. The mother's reproductive system could also suffer from physical defects, such as scar tissue that doesn't allow proper placental development, resulting in fetuses not receiving sufficient nutrients for growth.
During your dog's pregnancy, do not give her any medications or supplements before checking with your vet. Some common drugs, relatively safe to use in non-pregnant animals, can cause abortion or kill puppies in utero. These include dexamethasone, often prescribed as an anti-inflammatory.
As difficult as it is, collect dead puppies and put them in a plastic zip-lock bag to take to the vet for testing and necropsy. Include the placenta, if possible. If necessary, put the remains in the refrigerator if you can't get to the vet immediately. Wear gloves when picking up the puppies and placenta, since certain diseases are transmissible to people. You have to work fast, even through your grief, because it is the nature of dogs to consume dead fetuses.