Veterinarians typically recommend that pregnant dogs not receive any vaccines, including rabies, until they have whelped and weaned their puppies, to avoid possible effects to the litter. Your vet may also recommend avoiding other medications and treatments, such as flea and tick repellents, until the dog gives birth.
Rabies is a dangerous disease that can be contracted by dogs, other animals and humans from the bite of an infected animal. Rabies vaccines for dogs are required by law in every state and are usually given every three years, although some locales require yearly vaccinations. Some states allow dogs who experience serious reactions to the vaccine exemptions, which must be obtained through your vet.
Avoid introducing any chemical substance to a dog who is pregnant, including vaccines. Medications and vaccines can enter the placenta and damage the unborn puppies. Vaccinating a pregnant dog will not pass any protection on to her puppies, and can result in death or defects in the litter. It takes about a week for a mother dog's body to receive immunity to the disease from the vaccine, which can produce additional stress to her body. She must also produce colostrum and milk for the puppies, who receive immunity from her colostrum in the first 36 hours of life.
When you plan a breeding, check that the dog's vaccines are up to date and administer any vaccines needed at least four weeks before breeding. Never administer another vaccine at the same time as the rabies vaccine to avoid adverse reactions. Space vaccines two to four weeks apart.
Killed vs. Live
If a pregnant dog must be vaccinated, a killed vaccine should be used. Years ago, modified live, or active, rabies vaccines were given. But in the 1970s, the protocol was changed to killed, noninfectious vaccines. Killed vaccines are more powerful and effective for longer durations. Because they don't contain the active virus, they are considered safer. It is not recommended that pregnant dogs be vaccinated until their litter is weaned.
If you are vaccinating a pregnant dog, ask your veterinarian to check with the pharmaceutical manufacturer to be sure it is safe for pregnant and lactating dogs.