Can you vaccinate pregnant dogs? This is something many dog breeders may wonder about. A dog’s health after all depends on an efficient immune system. This system recognizes and destroys any foreign or damaging object inside the body, including rogue body cells. The system can be activated by physical or psychological causes and should turn on and off as necessary. Simply put, a healthy immune system recognizes and destroys both external disease-causing microbes, such as viruses and bacteria, and internal dangers such as cancer cells. It is constantly vigilant and occupied with these tasks.
Maternal Immunity and Vaccination
Antibodies conferring immunity to infectious organisms are passed from a mother to her young in the first milk called colostrum. At birth, the pup’s intestines are permeable enough to absorb these antibodies into the blood. After a few days, any remaining antibodies settle on the tonsils and the lining of the intestines. Maternal antibodies drop to low levels after about 10 to 12 weeks of age. Therefore, pups should be fully inoculated against major diseases between eight and twelve weeks.
Vaccination can be a highly effective way of preventing many killer diseases. Until a few decades ago, serious viral illnesses such as canine hepatitis and the highly contagious canine distemper were feared, but now they are relatively rare particularly in places where efficient vaccination protocols are routinely used.
Vaccines work by sensitizing the immune system to a particular disease-causing bacterium, bacterial toxin or virus. Most vaccines contain the organism or toxin against which protection is sought. However, this organism has been killed, genetically modified or weakened so that it does not cause illness, but still stimulates the body to produce antibodies against it. Later on, if the vaccinated dog encounters the disease, it remains healthy because it already has the antibodies to destroy the disease-producing agent.
Most vaccines are administered by injection, but some, such as the bordetella vaccine (which prevents kennel cough) are given by aerosol in the nose. The effectiveness a vaccine provides can vary. Some vaccines give lifelong immunity while others give only partial protection against a particular disease. This is mainly due to the fact that certain viruses are capable of modifying their form.
Basically, the vaccine can be effective against one form but not another. Although not dramatically, the canine parvovirus is capable of transforming and changing its form.
Sadly, vaccines can sometimes fail. These errors occur in the following situations:
- If the pups have high levels of maternal antibodies which may neutralize the vaccine
- If the dog is already infected with the disease, but does not show clinical signs yet
- If the dog has a faulty immune system
- If the vaccine has been handled, stored or administered incorrectly.
A Sample of a Vaccination Schedule
Your vet will recommend a vaccination protocol specific for your area and your dog. Strains of virus differ from one location to another. Additionally, some vaccines offer better protection than others. In an urban area, where the incidence of rat-transmitted disease is high and the vaccine quality is excellent, it is recommended to use the following protocol:
- 8 weeks – parvovirus and leptospirosis
- 10 weeks – parvovirus, leptospirosis, distemper and hepatitis
- 16-18 weeks – rabies, with boosters every 1-3 years
- 15 months – parvovirus, leptospirosis, distemper and hepatitis
- 1 year later – leptospirosis for dogs that swim or hunt rodents
- Every 3 years – parvovirus and distemper.
When vaccination should be skipped? There are certain situations in which it is better to avoid vaccination. Generally speaking, do not vaccinate your dog if it is:
- Under 8 weeks old
- Within 30 days of estrus or in estrus
- Pregnant or lactating
- Undergoing or within 30 days of corticosteroid treatment
- Injured, ill or under any severe stress.
Can You Vaccinate Pregnant Dogs?
At birth, pups gain protection against diseases to which their mother has been exposed, because maternal antibodies against diseases are passed on to the pup in the first milk or colostrum. However, boosting this natural protection through vaccinating the mother while she is pregnant is a quite controversial topic.
In a nutshell, vaccination should be avoided since the mother’s immune system is already compromised because she is carrying foreign protein (her own pups) in her womb. What is more, some experts go so far to forbid vaccinating any housemates of pregnant females, because vaccine virus can be shed by these dogs and then passed on to the mother-to-be.
On the other hand, if you have a non-vaccinated mother the chances of her puppies contracting communicable disease before they are old enough to receive their own vaccines is considerably high. All in all, when it comes to vaccinating your pregnant dog, there is no easy answer.
Generally speaking, if your dog has had all of her vaccinations and boosters there is no need to even consider vaccination during pregnancy. If your dog’s vaccinations and boosters have lapsed but not for long (less than a year or two) it is recommended to delay the vaccination until after the puppies are born and weaned. In both cases, thanks to the previous vaccines, the mother has certain level of protection.
However, if the mother has never been vaccinated, it is highly advisable to talk to your vet and examine all the options. In a small but yet significant number of cases, vaccinating a pregnant dog with a live vaccine can lead to spontaneous abortion. This is because the vaccine triggers the immune system to produce antibodies without actually making the dog sick. This principle works fine for adult dog but pups in the uterus are vulnerable and sensitive to the live components. To avoid the risks associated with live vaccines, you can ask your vet for special vaccines that lack the live component (killed vaccines).
Killed vaccines contain inactivated viruses or bacteria. Consequently, they do not replicate within the recipient’s body and are therefore unable to harm the puppies in the womb. Sadly, since these killed organisms do not replicate in the body, the immune response they trigger is not as strong and the immunity does not get significantly reinforced and amplified. Simply stated, when compared to live vaccines, killed vaccines are much safer but tend to promote immunity of a shorter duration and magnitude.
About the Author
Dr. Ivana Crnec is a graduate of the University Sv. Kliment Ohridski’s Faculty of Veterinary Medicine in Bitola, Republic of Macedonia. She currently practices as a veterinarian in Bitola and is completing her postgraduate studies in the Pathology of Domestic Carnivores at the Faculty of Veterinary Medicine in Zagreb, Croatia.Ivana’s research has been published in international journals, and she regularly attends international veterinary conferences.