Features October 2016 Issue

Puppy Vaccines: Why Your Puppy Needs So Many Shots

Ever wonder why puppies need multiple “shots” in order to become fully immunized? Here are the reasons behind puppy vaccine schedules and how best to strategize your puppy's immunizations.

[Updated December 19, 2018]

The first rule of puppy vaccinations is that there are no hard and fast rules for puppy vaccinations; the best way to make sure a puppy is fully immunized against the most common contagious diseases totally depends on the health and past history of the puppy's mother, his age, and his environment. A puppy being raised by a responsible breeder may require only one combination vaccination in order to become immunized; whereas a puppy raised in a shelter might be given as many as six or seven combination vaccinations before being declared fully protected. 

There are several reasons why puppy vaccination protocols vary so wildly, but the most important one to understand is that every puppy is an individual, presenting a unique and unpredictable immunological history to his veterinarian. If you understand the reasons that veterinarians recommend multiple "puppy shots," you will be better prepared to both protect your puppy from risky exposure to contagious diseases and, possibly, help reduce the number of vaccinations the puppy receives on the road to becoming fully immunized.

Few new dog owners understand why puppies need multiple “shots." Most veterinarians recommend that puppies are vaccinated for distemper, parvovirus, and adenovirus (hepatitis) a number of times, starting when they are about four to six weeks old, and again every three or four weeks, with their last “puppy vaccination” given after they are about 16 to 20 weeks old. The most common guesses as to why puppies need all those vaccinations?

A) Because it takes at least four vaccinations for full immunity.
B) Each shot “boosts” the immunity from the first shot.

The actual answer would be C) Neither of these. Repeated puppy vaccines do not increase or “boost” the immunity in any way. Vaccines are repeated in order to make sure the puppy receives a vaccination as soon as his immune system is able to respond as we want it to – to respond by developing antibodies to the disease antigens in the vaccines. Let’s do a bit of review, to make sure all the terms used here are understood.

Dog Vaccination Terminology

Let’s do a bit of review, to make sure all the terms used here are understood.

An antigen is a substance that induces a response from a body’s immune system. In this discussion, when we talk about antigens, we mean a form of the diseases that commonly infect puppies and dogs.

A vaccine is a form of disease antigen that has been altered in some way so that his immune system will recognize it as a foreign invader and respond to it by destroying substances that resemble that antigen in the future. Some vaccinations are made with “killed” viruses; some are genetically altered so they resemble the disease antigen but cannot make the animal ill (“modified live”); and still others are highly weakened, live strains of the disease.

Antibodies are the immune system protective substances that recognize and destroy the agents of disease (antigens).

When we administer a vaccine to a puppy, we are in effect training his immune system to recognize the disease antigen and mount an immune response to it – to form antibodies that will recognize and destroy those antigens whenever the dog comes into contact with them again.

When a puppy has been vaccinated and his immune system has formed antibodies to the disease antigens in the vaccines he received, he is considered immunized against those diseases.

How Maternal Interference Affects Puppy Immunization

Immunizing puppies is a tiny bit more complicated due to a mechanism called maternal interference.

All puppies who are nursed adequately by their mother in the first two or three days after birth receive some of her protective antibodies from drinking her “colostrum” – the yellowish substance that the mother produces before she starts actual milk production.

puppy vaccination

Given their mothers’ unknown vaccination status, puppies in shelters often receive more vaccinations, with the first ones administered earlier and the last ones administered later, than puppies bred and raised by professional breeders.

The mother’s antibodies protect the puppies for a highly variable amount of time – anywhere from about three weeks to about 12 weeks. These antibodies gradually “fade” from the puppies’ systems as the puppies’ own immune systems develop.

When a puppy is vaccinated during the period of time that his mother’s antibodies are still active in his system, those maternal antibodies will detect and destroy the disease antigen in the vaccine, rendering that particular vaccine useless to the puppy. He can’t develop his own antibodies to disease antigens until his mother’s antibodies have faded from his system. Also, while some puppies may have received a whopping dose of antibodies from their mom, others may have received few or none. If the mother was never vaccinated herself, and never came into contact with those disease antigens, she would have none of these antigens to pass along to the pups in her colostrum.

So, should puppy owners just wait to vaccinate puppies, until the time when any amount of maternal antibodies are sure to have faded (12 to 14 weeks is generally considered as the outer limit of any maternal interference)? The answer is NO, because we don’t know when any given puppy’s maternal immunity is going to fade, and he would have no protection from disease in the period between the fading of his mom’s antibodies and receiving his first vaccination.

A mother’s antibodies might fade when he’s three weeks old, when he’s 12 weeks old, or any time in between. If the protection he got from his mom fades at three weeks, and we don’t vaccinate him until he’s 14 weeks old, he is vulnerable and without any protection whatsoever, until at least a few days after his vaccination. That’s too long to go without protection, unless you plan to raise him in a sterile bubble. And there are many compelling reasons having to do with his behavioral development to not just keep him home.

Why Puppies Might Receive Excess Shots

Instead, we give the puppy a series of vaccinations, about three to four weeks apart, starting when the puppy is four to six weeks old. The idea is to try to reduce the size of the “window of opportunity” when the mom’s antibodies fade (leaving the puppy unprotected) and the next vaccine is given, to reduce the chances that he comes into contact with disease antigen when he is unprotected.

It might be that the mother’s antibodies faded early, and the first vaccine was given at four weeks, and he developed his own protective antibodies. In this case, he doesn’t actually need any further vaccines, but we don’t know that, so he is given additional vaccinations every three to four weeks until he’s about 20 weeks old. It’s more than he needs, but at least he was protected.

Or it might be that the puppy was vaccinated at five weeks, again at eight weeks, and again at 11 weeks, but his mother’s antibodies were still circulating until he was about 12 weeks old. The mom’s antibodies would have neutralized all those first vaccines, so when the antibodies finally faded, he was left without protection from disease until his next vaccine was received at 14 weeks. This is actually the worst-case scenario, because many puppy owners are taking their pups into high-risk environments at this age, thinking, no doubt, “He’s had three shots already; he must have at least some immunity by now!”

There is no practical way to know whether the mother’s antibodies are still circulating in a puppy’s body or when they have faded. And each mother and each puppy is an individual; she will pass along a variable amount of antibodies, and these will fade at different times in each puppy. So we vaccinate several times, until we are past the point in time when any maternal antibodies can interfere with proper immunization. 

Dog Shelter Vaccination Protocols May Vary

Puppies who have been bred and raised by a professional, responsible breeder are likely to be given far fewer vaccines than puppies who came from a shelter environment. In a professional breeding program, the mother dog’s vaccination status will be known, and her first nursing session will be observed, so better assumptions can be made about how much protection the puppies will receive from her maternal antibodies. Further, the breeder will likely have experience with keeping the puppies from being exposed to disease antigens, by requiring visitors to remove their shoes, wash their hands, and so on. These protections may allow the breeder to administer the first puppy vaccines at eight weeks or later, and perhaps just one or two more vaccines (with the last one given after 16 or 18 weeks).

Puppies who have the misfortune to be born in or surrendered to a shelter after birth may not receive any antibodies from their mothers; if their mothers were not vaccinated or otherwise exposed to the core diseases, they wouldn’t have antibodies to pass along. Also, puppies may not have had sufficient access to colostrum. In addition, shelters are often teeming with infectious disease agents. For all of these reasons, puppies who are born and/or raised in a shelter environment may be vaccinated much more aggressively – some might say excessively – than puppies who were born with more advantages.

Shelters often vaccinate puppies for the first time at just four to six weeks of age. At four weeks, the puppies’ immune systems are just barely mature enough to develop antibodies following exposure to disease antigens; this is done in an effort to immunize puppies who didn’t receive any maternal antibodies as quickly as possible.

Another vaccination protocol common in shelters is vaccinating every three weeks until the puppies are 16 to 18 or even 20 weeks of age. In this case, it’s the possibility that the puppies received far more than the usual amount of maternal antibodies than usual that causes shelters to take this tack.

If an unvaccinated dog contracts and then survives a disease like parvovirus, she actually develops far stronger immunity to the disease than she would had she been vaccinated against the disease in the first place – and she will pass along this very robust protection to her puppies (as long as they receive an adequate amount of her colostrum). Her antibodies will likely take the longest amount of time to fade in her puppies, so her puppies need to have their final vaccines a bit later in order to prevent this strong maternal antibody interference.

Finally, there is the sad fact shelter staffers often have to guess at the age of the puppies in their care. Shelter immunization protocols are usually designed with enough overlap to ensure that a puppy has every possible chance of receiving adequate protection from contagious disease.

Finishing Your Puppy's Vaccinations

A puppy is considered fully immunized against the “core” (the most common, and most problematic) diseases of adenovirus (hepatitis), distemper, and parvovirus when he has received a vaccination for these diseases after the age of 16 to 18 weeks. (Note: Until recently, the “puppy shots” were considered complete when the last one was given at 16 weeks. New research states that final puppy parvovirus vaccine should be at or after 18 weeks of age.)

Rabies is another “core” vaccination, but it is not given to puppies before 12 weeks of age. A puppy can receive his first rabies vaccine at 12 weeks (but no sooner), and should be given another rabies vaccine a year later. A vaccination is required by most states every three years afterward. (This is a matter of state law, put in place for the protection of human health; a dog who has received two or more rabies vaccines is likely protected from that disease for life.)

Until the final “puppy” vaccines are given at 16-18 weeks, the puppy should be protected from potential exposure to disease antigens, but this doesn’t mean he shouldn’t ever leave the house until the time of his final “puppy shot.” It just means that his exposure to the outside world should be carefully considered. Do bring him to the homes of relatives and friends whose dogs are demonstrably healthy, vaccinated, and friendly. Do not take the puppy for walks in places that are highly trafficked by unknown dogs, such as sidewalks, parks (especially dog parks), pet supply stores, and so on.

Also, if someone in your home has tracked through places that are likely to be covered with agents of contagious disease – such as a dog park or veterinary clinic – keep their shoes outside the front door, and ask them to wash their hands before they play with the puppy.

If you attend puppy training or socialization classes, be sure the instructor takes the following precautions:

  • The puppy school should require each puppy’s vaccine records, to make sure all the puppies are in the process of receiving veterinary care and proper protection from either catching or spreading disease
  • A puppy with any signs of illness (such as lethargy, vomiting, diarrhea, and/or an increased temperature) should be disallowed from attending class.
  • There should be equipment on hand so that every “accident” that a puppy has in class can be quickly cleaned up with a proper antibacterial solution.

Passing the Puppy Titer Test

The vast majority of puppies will be successfully immunized after the series of vaccinations described here, but a tiny percentage will be what are called “non responders” – incapable of developing protective antibodies in response to vaccines. These dogs will be vulnerable to infection by these diseases, no matter how many times they are vaccinated, and thus should be protected from high-risk environments (wherever a lot of dogs congregate).

There is a way to determine whether the final vaccination (at least) that was administered to your puppy triggered his immune system to develop protective antibodies for the “core” diseases he was vaccinated for. At least two weeks after what is hoped will be the puppy’s final vaccination – at approximately 18 to 20 weeks of age – you can ask your veterinarian for a “vaccine titer test.” A blood sample is taken, sent to a laboratory, and tested for the presence of antibodies that protect the puppy against parvovirus and distemper. If these antibodies are detected, he’s done with his core vaccinations.

However, if the vaccine titer test comes back with a negative result, it’s recommended that the puppy be vaccinated one more time, perhaps with a different brand of vaccine than was used previously. Two weeks later, the vaccine titer test should be repeated. If the result is still negative, the puppy will be considered a non-responder, vulnerable to contracting any of the core diseases he may be exposed to.

Vaccine titer tests are being increasingly used by knowledgeable owners who want confirmation that their puppy is protected from disease, but there are still many veterinarians who are unfamiliar with the tests, and/or skeptical of their usefulness. Some clinic managers may be unable to quote a price for this test, or unsure of what test to order from the laboratory they use. We’ve heard of clinics charging as much as $200 for the test, which is ridiculous. In contrast, highly progressive clinics may offer a SNAP (in-office) test that will reveal the results within a half-hour.

Alternatively, ask your veterinarian to take a blood sample, and send it to the Dr. Ronald D. Schultz Laboratory at the University of Wisconsin (Madison) School of Veterinary Medicine. This lab charges just $25 for the test (though you will need to pay for the blood to be drawn and shipping the to lab). See Dr. Schultz's website for instructions and an order form.

Nancy Kerns is the editor of Whole Dog Journal.

Comments (20)

Dear Images47, I hear what you are saying. However, even if "shelter dogs" are being vaccinated at 4 weeks, their systems can still be overwhelmed just like any other dog. Too bad the shelters don't have enough money to titer puppies, so the new owners don't have a potential "auto-immune diseased" mess that they have to deal with the rest of the life of the dog they got from a shelter. Many people who obtain their dogs from shelters don't have the money to begin with to deal with health issues down the line, so, the dog ends up in a shelter again...

Posted by: estee | February 12, 2019 5:32 PM    Report this comment

Dear Estee, please read the article AGAIN. She said SHELTERS - Humane Societies (not ethical or educated breeders) give an over abundance of shots to puppies, BECAUSE they don't know the diseases status of other dogs they take in. I watched an episode of the Rocky Mountain vet where a person rescued a whole litter of very young puppies from Texas. They were exposed to Parvo and all DIED except one. All she is doing is warning readers that if you rescue a young puppy from a shelter expect they have may have had an over abundance of shots. Now if shelters could be given the ability to test for immune status perhaps there could be less shots given to and sick dogs put into isolation.
Not every shelter has people who will take and care for a litter of puppies. Also remember a dog that has parvo and lives still sheds the active virus into the world.

Posted by: Imajes47 | February 12, 2019 2:38 PM    Report this comment

And starting them a 4 weeks!!!!!! Let's just quadruple the damage while we're at it, yah?

Posted by: Donnasandy | October 10, 2018 7:10 PM    Report this comment

Yes, sadly, WDJ has sold out and gone completely mainstream. After subscribing for YEARS, I will not renew. And please, before you buy into this vaccination BS, look up the vital pet website to learn how negatively all these vaccines will affect your pet, and the MUCH safer alternatives. Whole Dog Journal, you're becoming a disgrace to your own name. Maybe it's time to change it.

Posted by: Donnasandy | October 10, 2018 7:08 PM    Report this comment

Im a breeder and this an article written in the middle ages.
We have our puppy's checked with the Vaccicheck titertest at age of 8 weeks and they always are high in their maternal antibodies which means vaccination at this point is useless. My Vaccicheck specialized vet writes the vaccicheck outcome in the passports of the puppy's with an advise when to vaccinate or if the antibodies are very high another appointment for a second vaccicheck. The new owners have to look for a vet also specialized in vaccicheck to follow the path we choose to follow. This way the puppy's won't be harmed by overvaccination and are fully protected. The vaccicheck is officially wordwide accepted as we show our dogs all over Europe with no problems passing borders or entering showaccomodation. Overvaccination is a very health disturbing thing used back in the middle ages but not acceptable for this time anymore with the vaccicheck available all over the world. When a vet doesn't use this the vet is not up to date! Google the vaccicheck and you'll get all the info in English with lists of vets who use it.

Posted by: Anja | October 10, 2018 5:32 AM    Report this comment

I am all for titer testing. Vets really need to be informed and volunteer the tests, but we all know that will never happen. We have to advocate for our babies.

Posted by: mimiathome | October 9, 2018 3:26 PM    Report this comment

Clearly, I am way behind on reading WDJ. I have a question—why can’t you do a titer test after first round of immunizations to check if puppy is protected and proceed based on result?

Posted by: Christy | August 11, 2018 2:24 PM    Report this comment

Dr. Schultz has retired, but Dr. Laurie Larson is the researcher to contact with regard to the antibody testing.

She can be reached at 608-263-4648.

Posted by: Calirose | October 18, 2017 3:16 PM    Report this comment

My vet is an excellent vet but he has a particular shot protocol that he uses. I brought in the shot protocol by Dr. Dodd and showed it to him. He was reluctant but eventually agreed. She just had her first set of bloodwork drawn to check titer levels for the combo shot and her levels came back way up over the minimum threshold. He was clearly surprised by the results. I also insist that no more than one vaccine be given in any 6 month period so we waited to do rabies. I refuse to do the leptospirosis shot because it is known to be problematic and not common in my area. I do however, keep her kennel cough up to date. I firmly believe that the less vaccines you can get away with the better. My girlfriend's dog got a lepto shot at the age of 4 because her vet thought somehow that a 12 lb housedog that lived in the suburbs and never went into deep grass let alone the woods, needed this shot. Suddenly the little guy became allergic to many foods and environmental triggers. He broke out in hives at the drop of a hat and would itch so intensely that he would lick the carpet in frustration because he was so miserable. The condition worsened with age and he had a very poor quality of life. I would do anything to prevent this from happening to my dogs.

Posted by: Mel Blacke | October 16, 2017 4:30 AM    Report this comment

Jennifer: This site won’t let me post an external link, but if you do a google search for “dog titer test University of Wisconsin” you will find it. Bobbie

Posted by: SophiesMom | October 15, 2017 7:24 PM    Report this comment

I agree with all, but the Doctor who uses the iron lung analogy. Good grief. Wonder if he knows High doses of IV Vitamin C were curing polio 10 years before chemical lobotomy inducing Big Pharma came up with their latest, greatest and squashed the research of Claus W. Jungeblut, like a bug. Ethical bunch they are. "Whole Dog" cannot continue down this road and expect to keep many readers that know what is going on, so quit being on the take and fly right guys.

Posted by: majk1004 | October 15, 2017 6:56 PM    Report this comment

Two highly respected researchers who provide titer tests (with reasonable fees) would be: Jean Dodds, DVM of www.hemopet.org. And Dr Ron Schultz Laboratory, Madison, Wi. Phone # 608*263*4648.
Both have worked together on the Rabies Challenge Fund.
Dr. Dodds' web site in particular is a wealth of information.

Posted by: Houndz6 | October 15, 2017 3:32 PM    Report this comment

To the physician spoken like some one schooled in western medicine only. I bet the doctor is all for giving a hep b immunization to an hours old child also. So they can either shoot it up or play in the sewer. No, not my child nor grandchildren. Nor any child in our family.

Posted by: Bunny | October 15, 2017 2:05 PM    Report this comment

Another concern is why should a 3 pound puppy get the same dose as a 30 pound puppy? And they should need none due to mothers protection if she is fully vaccinated until between 3 to 4 months. My pups receive core vaccines only and never the kennel cough. As it only protects between 4/7 of the 100 plus common colds out there. And the flu vaccine is a huge hoax. Not looking out for the health of your pup at all. Never lost a dog to any of the worried about diseases. And immune systems were very healthy. Watch out for Banfield they are needle happy. All my pups eat raw. Do only core vaccines then titer test. Yea, it costs some but what is your fur friend worth to you?

Posted by: Bunny | October 15, 2017 1:57 PM    Report this comment

Oh come on. Serious side effects of vaccines compared to the benefits? I’m a doctor and I see this all the time with humans and their babies. I show them pictures of iron lungs and ask them if they really want to see polio come back in America.

Posted by: vboisen | October 15, 2017 1:37 PM    Report this comment

Lol, that was supposed to be titer test.

Posted by: Donkette | October 15, 2017 1:23 PM    Report this comment

Can someone help direct me to the form for the tired test? The link I follow says not found.

Posted by: Donkette | October 15, 2017 1:21 PM    Report this comment

I am a breeder that has a pretty good understanding of how vaccines work (I've been to two seminars by Dr. Ron Schultz). Because of this, I think you have made some mis-statements based on "vaccine guidelines", of which Dr. Schultz was a big part of. NO WHERE has Dr. Schultz claimed or as outlined in the Vaccine Guidelines that the initial vaccine should begin between 4 to 6 wks. Vaccinating a puppy at 4 wks could overwhelm/over stress their system. in the official protocol, they state the first vaccine should be given between 6-8 wks, and Schultz himself states, preferably an 8 wk start. I don't know where you got this information. I tried to copy and paste the AAHA Vaccine Guidelines, but had not luck.

Posted by: estee | October 15, 2017 12:18 PM    Report this comment

Agree with 1st comment. This article sounds like something written by a pro-pHARMa rep. Nothing is mentioned about adverse reactions, ingredients in adjuvants, efficacy, the inserts themselves. Very disappointing considering Whole Dog Journal used to be a fairly reputable holistic wellness journal for canines. This article falls very short of that.

Posted by: UnicornDreamsFarm | October 15, 2017 11:14 AM    Report this comment

And not one word about the serious side effects of vaccines? I am very disappointed!
Vaccines are NOT the holy grail of dog health, or of anyone's health for that matter...

Posted by: Hapschaartje | October 15, 2017 10:46 AM    Report this comment

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