Vaccinations / rabbies shots for dogs

How Often Should You Vaccinate Your Cat or Dog?

**** PART ONE OF FOUR ***
Today I'm interviewing a very special guest at his facility, Dr. Ronald Schultz, Professor and Chair, Department of Pathobiological Sciences, School of Veterinary Science at the University of Wisconsin – Madison.

Some Background on Dr. Schultz
Dr. Schultz has been at University of Wisconsin – Madison for 29 years.

He explained there are about 150 faculty staff and students in his department, which is one of the four largest departments at the university, and a very important element of any veterinary school. The Department of Pathobiological Sciences is involved in a variety of scientific subjects, including bacteriology, immunology, virology, parasitology, public health, epidemiology and clinical and anatomic pathology.

Dr. Schultz's specialty is veterinary immunology. One of the reasons I'm excited to interview him for MercolaHealthyPets.com is because as readers here learn to make better decisions about vaccinating their pets, they will undoubtedly come across Dr. Schultz's name and his work in the field.

The doctor is involved in every aspect of the topic of veterinary vaccines – he has worked alongside vaccine manufacturers, developed vaccination protocols, and tested protocols.

Dr. Schultz is a hands-on researcher in the field of veterinary vaccines, and it's an honor to be able to speak with him today.

A Little Veterinary Vaccine History
Vaccination is one of the most hotly debated topics in veterinary medicine today. The reason is because while on the one hand we want to protect companion animals from deadly infectious diseases, we are also very concerned with the problems created by over-vaccination.

When humans are vaccinated against diseases like measles, mumps, rubella and DPT, the immunizations given in childhood provide lifetime protection. They are not given again in that child's entire life, much less repeated every year.

When I worked at a humane society 20 years ago, our protocol was to give puppies a five-way combination vaccine at 6, 8, 10, 12, 14 and 16 weeks, followed by an annual booster every year for the rest of their lives.

When I got to veterinary school and learned vaccines never wear off, I became quite confused about why vets recommend yearly re-vaccinations. So I asked Dr. Schultz how dogs and cats develop immunity.

Dr. Schultz explained that my questions were the same ones he asked back in the 1970s – how often do dogs and cats need to be vaccinated, and what vaccines are really required?

In the 1970s there weren't a lot of vaccines available for pets, so according to Dr. Schultz, every time a new one became available, it was added to the syringe.

By the 1980s, there were 12 or 14 different vaccines being delivered as combination products. As an immunologist, Dr. Schultz knew that was not a good idea. And vaccinated pets were beginning to develop adverse reactions, so their bodies also knew the combination vaccines were a bad idea.

In 1978, Dr. Schultz and a colleague, Dr. Fred Scott developed and published a vaccination protocol. It called for pets to receive puppy or kitten shots, be vaccinated again at a year of age, and then be re-vaccinated every three years or less frequently thereafter.

Change is often a very slow process, and it wasn't until 1998 that the American Association of Feline Practitioners issued guidelines very similar to what Dr. Schultz and Dr. Scott published 20 years earlier.

Core vs. Non-Core Vaccines
There are a lot more vaccines available today than there were back in the 1970s, but we now know there are certain vaccines, called the 'core vaccines,' that every dog and cat should receive.

Canine core vaccines include:

•Distemper
•Parvo
•Adenovirus
•Rabies
Feline core vaccines:

•Panleukopenia
•Calici
•Herpes
•Rabies
The diseases these vaccines protect against are very serious, with mortality as high as 60 to 80 percent in young animals. That's why every kitten and puppy should receive these core vaccines very early in life.

All other vaccines are known as non-core, or optional. Only certain animals need non-core vaccines, as opposed to every animal needing the core vaccines.

I next asked Dr. Schultz for his thoughts on what vaccines are necessary for indoor-only cats that never come into contact with outdoor cats.

Dr. Schultz recommends only the core vaccine panleukopenia for indoor kitties. He explained the last dose should be at 14 to 16 weeks, because by that time the kitten will no longer have the protection passed from the mother cat.

Litters from immunized cats and dogs have some protective antibodies from their mothers at birth. These antibodies are systemic, but they have a finite life. They ultimately die off, but the level of immunity in the mother determines when that die-off occurs in the kittens or puppies. It is only when the antibodies from the mother die off that a vaccination actually immunizes the puppy or kitten.

Vaccination vs. Immunization
I asked Dr. Schultz to expand on the difference between being vaccinated and being immunized. According to Dr. Schultz, and I certainly agree, we tend to do a lot of vaccinating, but at times we don't do much immunizing – especially when it comes to kittens and puppies.

The maternally-derived antibodies passed to puppies and kittens can actually block vaccines from working. It's one of the reasons we give a series of vaccines to young animals.

In the 1960s and 1970s when we first started using vaccines, vets would create a nomograph for litters to determine when they could be effectively vaccinated. The nomograph was based on the antibody titers of the mothers. Using half-life to predict when the mother's antibodies would wear off in her babies, we could determine exactly when the puppies or kittens should be immunized. Maternally-derived antibodies wear off between about five and a half and nine weeks.

The time period between when the maternal antibodies die off and the baby's immune system is strong enough to protect it provides a window of opportunity in which if the puppies or kittens are exposed to a virus it can kill them.

The purpose of vaccines is to stimulate the immature immune system to make antibodies so if in the event a puppy or kitten is exposed to an infectious disease, it will be able to mount an immune response to fight it off.

The beauty of the nomograph is it provides the information needed to vaccinate a puppy or kitten only once, because it predicts pretty much exactly when the litter will no longer be protected by maternal antibodies. This allows you to give the kitten or puppy the correct vaccines at the appropriate times, and avoids giving unnecessary vaccines.

A drawback to use of the nomograph method is that it takes a fair amount of time to get the results. Another drawback is the maternally derived antibodies for the various viruses die off in the puppy or kitten at different times. For example, a puppy might respond to distemper at 8 weeks, but not to parvo until 12 or 14 weeks.

If you work with a holistic vet that uses single vaccines, this is a perfect way to custom formulate an ideal vaccine schedule, however, the majority of people don't, and that's why the puppy or kitten series of vaccinations became popular – there was no waiting and it was much less expensive as compared to titering.

Stay tuned next week for part 2 of this 4-part interview with Dr. Ronald Schultz. Next week Dr. Becker talks with Dr. Schultz about recommended vaccination protocols and vaccine non-responders



*** PART 2 OF 4 ***

Today I'm continuing my interview with Dr. Ronald Schultz, Professor and Chair, Department of Pathobiological Sciences, School of Veterinary Science at the University of Wisconsin – Madison.

Last week in part 1, Dr. Schultz and I talked about core and non-core vaccines and the difference between vaccinating and immunizing. Today we continue our discussion of core vaccines for puppies and kittens and the length of immunity received from these vaccinations.

Core Vaccine Recommendations for Puppies and Kittens
Dr. Schultz recommends not starting a puppy or kitten vaccination program before 6 to 8 weeks of age, with re-vaccinations no more frequent than every four weeks. For example, if you start the program when a puppy is 8 weeks old, you would give another dose of the core vaccines at 12 weeks, and the third dose at 16 weeks.

What I do at my Natural Pet animal clinic is a first round of the cores before 12 weeks of age, like at 9 to 10 weeks. Then we boost between 15 and 16 weeks. Then we titer two weeks after the last round to see if there's been a response.

Dr. Schultz points out that we want to make sure the vaccinations have actually induced an immune response in the puppy or kitten. The best way to make that determination is with antibody titer tests for distemper and parvo in puppies, or panleukopenia in kittens, done between two to four weeks after the last vaccination.

When a puppy or kitten is between 14 and 16 weeks, the maternally-derived antibodies have dropped off, so there's no need to worry about residual antibodies left over from mom. If there's antibody present in the titer test, we know the baby's immune system has responded to the vaccine. This means we've not only vaccinated, but we've actually immunized as well.

Achieving immunity is the goal. We can put a lot of vaccines into pets, but if the dog or cat doesn't have a functional immunologic response, it's useless. Which means the animal has received all the toxicity of the vaccines and none of the benefit. The reason for vaccinations is to provide protective immunity against life-threatening diseases.

Vaccine Non-Responders
I asked Dr. Schultz at this point to briefly explain the rare circumstance in which there's a non-response to vaccination.

Unfortunately, there are genetic non-responders, which are animals that won't be immunized through vaccination no matter when they are injected.

Dr. Schultz estimates that about 1 in 1,000 puppies in the general population of dogs is a parvo non-responder. But because this is a function of genetics, certain breeds and more importantly, certain families (lineages) of dogs will have a much higher ratio than 1 in every 1,000. It might be 1 in 100, or even 1 in 10 that have no response.

Fortunately, animals that don't respond to one vaccine usually respond beautifully to the others. The non-response seems very strictly defined to a specific vaccine for a specific disease.

For distemper, the non-responders are about 1 in 5,000 in the general population. Dr. Schultz thinks this is probably due to the fact distemper has been in the canine species for much longer than parvo. Parvo didn't become a problem for canines until the late 1970s.

Puppy and Kitten Shots Often Provide Lifelong Immunity
Back to the subject of core vaccines and establishing immunity in puppies and kittens …

After we've established protective immunity with a modified vaccine protocol and titers to insure an immune system response to the vaccines, those pets are protected for life.

If we follow the protocol as laid out above, titering two to four weeks after the last round of vaccines at 14 to 16 weeks of age, and we confirm the babies' immune systems have responded to the vaccinations, there is no reason to continue to re-vaccinate those animals.

There's no reason to re-vaccinate, because giving a dog or cat boosters of the same vaccines doesn't mean he's more protected. Many pet owners are led to believe -- often by the reminders sent by their veterinarian's office -- that the vaccines 'expire.' It's frustrating, because these reminders are intended to provoke fear in responsible pet owners.

Dr. Schultz points out that like the MMR vaccine for children, the three core vaccines for puppies and kittens have the potential to provide lifelong immunity. We're not positive that every animal receives lifelong immunity, which is why we vaccinate a few times during that animal's life.

It depends on whether you want to take a minimalistic approach to vaccinating, which both Dr. Schultz and I take with our pets. But a lot of pet owners aren't comfortable with that approach.

What Dr. Schultz recommends for puppies and kittens that don't receive antibody titers two or more weeks after the last puppy shot, re-vaccination should be done in a year, which is what the American Animal Hospital Association and the American Association of Feline Practitioners recommend.

Going forward, Dr. Schultz recommends re-vaccination after 3 years or longer, but not more often than 3 years. Since the majority of these pets will have received immunity for life, many pet owners end up opting to titer at three years rather than to automatically vaccinate. The option with the 3-year guideline, then, is whether to titer to test immunity or go ahead and vaccinate.

Most visitors to MercolaHealthyPets.com aren't interested in vaccinating their pets when it's not necessary, so that's when titering becomes a great option to have. At my animal hospital, we don't automatically revaccinate every 3 years for animals that were not tittered 2-4 weeks after their last puppy/kitten vaccine, we titer instead (to see if additional vaccines are needed).

Titering Methods
Next I wanted to talk with Dr. Schultz about the different methods of titering, as there are several.

The 'gold standard' titer tests are performed only in diagnostic labs associated with veterinary schools, whereas the commercial tests that are available use different methodologies. The commercial test results are correlated with gold standard test results so they can be understood.

Diagnostic labs report results in terms of numbers which they attach great importance to. Dr. Schultz believes the specific numbers don't mean anything as long as they're positive – which indicates the presence of an immune response. It's important to note that any measurable titer means the immune system responded. Some some labs recommend revaccination when a titer is present, but low. This is not what Dr. Schultz or I recommend.

If you have results on one of the gold standard tests -- like the Virus Neutralization Test for distemper – of, say, a 4 or an 8 or a 16 or a 32 or a 64, that means that animal's immune system has developed antibody, it is primed. And if the animal is exposed to distemper, if the distemper isn't immediately neutralized, there will be a secondary memory response and the animal will be protected.

Just like with you or I, if we encounter a flu virus we haven't been exposed to in 10 or 20 years, our immune system will retain memory to produce an adequate immunological response to the virus.

Stay tuned next week for part 3 of this 4-part interview with Dr. Ronald Schultz. Next week Dr. Becker talks with Dr. Schultz about rabies vaccines and recommendations for pets that have had a vaccine reaction.




** PART 3 OF 4 ***
Today I'm continuing my interview with Dr. Ronald Schultz, Professor and Chair, Department of Pathobiological Sciences, School of Veterinary Science at the University of Wisconsin – Madison.

In part 1 of this series, Dr. Schultz and I talked about core and non-core vaccines and the difference between vaccinating and immunizing. In part 2 we continued our discussion of core vaccines and the length of protection they offer.

The next subject I wanted Dr. Schultz to talk to us about is the vaccine that is mandatory in every state in the U.S. – the rabies vaccine. I want to talk about why some states have 1-year and 3-year vaccination options.

Some of my Natural Pet clients think the 3-year vaccine is 3 times stronger. Others think it has been researched 3 times longer. So I asked Dr. Schultz to shed some light on the subject of rabies vaccines.

Rabies Vaccines
Dr. Schultz points out that the rabies shot is a good example of a noninfectious vaccine.

Prior to the mid-1980s, all canine and feline rabies vaccines were what is known as 'modified live.' One dose was adequate to immunize a puppy or kitten. We generally gave those vaccinations at 12 weeks or older, when there was no maternally-derived antibody left to interfere.

Back in those days, with the modified live vaccine, we re-vaccinated each year because we didn't know whether immunity lasted longer than a year.

In the late 1970s – early 1980s, some kittens given rabies vaccines in California actually acquired the disease. That situation caused the USDA to rethink the wisdom of the modified live rabies vaccine. In reality, though, rather than the modified live vaccine turning virulent, it could have been that the kittens were severely immunosuppressed. They might have been infected with feline leukemia and/or feline immune deficiency viruses, which made them susceptible to the rabies virus.

Whatever the cause of the kittens developing rabies, it was decided modified live or infectious rabies vaccines were no longer advisable. At that point, we moved entirely to a non-infectious, killed, inactivated rabies vaccine. Inactivated vaccines are not as potent as modified live products.

However, we never changed the rabies vaccination one-dose protocol, even though we changed the vaccine. My recommendation back in the mid 1970s when we made the switch to an inactivated product, was to give two doses, 2 to 4 weeks apart, and then re-vaccinate in a year. But that's not what happened.

Fortunately, the rabies glycoprotein antigen in the killed vaccine is very powerful. And an adjuvant was added, which is the case with most inactivated vaccines.

An adjuvant is a very strong immuno-stimulant, and the one added to the killed rabies vaccine provided enough boost to the glycoprotein that one dose was enough to immunize most pets for a year.

As a general rule for killed vaccines, if we go much beyond 6 to 8 weeks between the two doses, we're providing essentially no protection at all. The leptospirosis vaccine is a good example – we could never go beyond 6 weeks between the two doses, because immunity would not be established. The lepto antigen is very weak compared to the rabies antigen.

Adjuvants in Pet Vaccines
I asked Dr. Schultz to discuss the use of adjuvants in veterinary vaccines. We know that thimerosal, an adjuvant included in human vaccines, has been removed due to health concerns.

Dr. Schultz points out there are a number of substances commonly added to vaccines, for example preservatives. Thimerosal, which contains mercury, is a very effective preservative. It has been added to human vaccines for many years, however, it hasn't been used in many veterinary vaccines.

Thimerosal is a concern because it contains the heavy metal mercury, which can cause adverse reactions and is very neurotoxic at high levels. The majority of human vaccines no longer contain thimerosal, and Dr. Schultz is not aware of any veterinary vaccine that contains it.

Aluminum is commonly found in human vaccine adjuvants. It is also used in some veterinary vaccines, but according to Dr. Schultz there are many other options for adjuvants in veterinary medicine. Veterinary vaccines are actually far ahead of the curve as compared to human vaccines. There are veterinary vaccines with new technology that have yet to be approved for use in human vaccines.

Veterinary medicine has an edge over human medicine when it comes to research and application of new vaccine technologies, including adjuvants. One of the reasons for this is studies can be done on the animals for whom the vaccine is being developed rather than on, for example, rodents which is how initial studies are conducted in human medicine.

Adverse Reactions to Pet Vaccines
I next wanted to talk to Dr. Schultz about vaccine reactions. It happens, unfortunately. We see pets die from adverse reactions to veterinary vaccines.

There are different types of allergic reactions, for instance anaphylaxis and also long-term, progressive, degenerative auto-immune disease. I asked Dr. Schultz if he sees a correlation between over-vaccination and an increase in autoimmune conditions in pets.

Dr. Schultz agrees autoimmune disorders are more prevalent in both pets and humans than they were 20 or 30 years ago. He thinks there are a number of reasons for the increase, and without question, vaccines are among them. Dr. Schultz also blames the presence of intoxicants, environmental pollutants and chemicals in our world today.

He believes there are a lot of factors in the environment that in a genetically predisposed individual can trigger immune-mediated disease. He stresses the key role genetics plays in immune-mediated and hypersensitivity-type diseases.

Recommendations for Pets That Have Had a Vaccine Reaction
At my clinic, I follow a very minimalistic vaccination protocol which includes titering to insure immunity has been achieved. But when I see animals that have had vaccine reactions, under no circumstances will I continue to vaccinate. I simply won't do it.

I asked Dr. Schultz about his recommendations for pets that have had a reaction to a vaccination. He agrees my approach is the best one under most circumstances.

If the reaction is to a core vaccine and the pet is successfully immunized, Dr. Schultz recommends titering. If there's any measurable antibody in the titer, that vaccine should not be given again. If there's no antibody for one of the cores, he feels we have an obligation to make sure the animal is protected because the diseases the cores protect against are so deadly.

Dr. Schultz points out a few options, including pre-treating the pet depending on what the reaction has been, but that won't provide assurance the animal won't have another reaction.

We can also switch products and hope something in the prior vaccine that isn't in the replacement product is what caused the reaction. But that's also no guarantee there won't be another reaction. An animal may be, for example, hypersensitive to bovine serum albumin, which is very likely contained in every vaccine manufactured for a particular disease.

In terms of risks vs. benefits of re-vaccinating an animal that has had a reaction to a vaccine, I'm not personally comfortable with the risk and would not re-vaccinate due to the potential for a more severe reaction.

Dr. Schultz says we want to make sure the animal is immunized against the core diseases. If the adverse vaccine reaction is to a non-core product, which it very often is (core vaccines are much safer than non-core vaccines in terms of adverse reactions), Dr. Schultz's position to is forget about that optional vaccine, whether it's the lepto vaccine or the Lyme vaccine or injectable bordetella, for example.

And I agree. If your pet has had an adverse reaction to a non-core vaccine and your vet is still recommending it, refuse it.

Stay tuned next week for part 4 of this 4-part interview with Dr. Ronald Schultz. Next week Dr. Becker and Dr. Schultz return to the topic of rabies vaccines. The doctors also discuss the protocols they follow in vaccinating their own pets.


***** PART 4 OF 4 ****

Today I'm wrapping up my 4-part interview with Dr. Ronald Schultz, Professor and Chair, Department of Pathobiological Sciences, School of Veterinary Science at the University of Wisconsin – Madison.

We're returning to the subject of rabies vaccines and Dr. Schultz's fascinating work in this area.

Are Rabies Vaccinations Really Needed Every Year or Three Years?
I asked Dr. Schultz to explain why there are 1-year and 3-year vaccines, but not, say, 7 or 12 or 20-year rabies vaccines.

Dr. Schultz explains he's conducting studies at the moment to successfully demonstrate a minimum duration of immunity for rabies at 7 years. This could enable us to extend the time between re-vaccinations. Up to now, no one has done the research to prove we can go beyond 3 years.

Part of the reason is because the studies are very expensive and take a lot of time. Currently Dr. Schultz is in year 4 of his 7 year study. You can read more about the study at the Rabies Challenge Fund. He is looking to be able to recommend that after an animal is vaccinated at from 12 to 24 weeks of age for rabies, it doesn't require a re-vaccination every 3 years.

Every state in the U.S. now has a 3-year rabies law, however, depending on what city or municipality you live in, the laws may be more restrictive, requiring every-year or every two-year rabies vaccines.

Dr. Schultz reminds every pet owner that you are the one with the ability to get the laws changed if you live in a location that requires your pet be vaccinated more frequently than every 3 years for rabies. There is absolutely no scientific reason for anyone to vaccinate an animal more often than every 3 years with products that are licensed by the USDA to be given at 3 year intervals.

Re-vaccinating that animal more frequently will not enhance herd immunity or protection against rabies. Animal owners who never have their pets vaccinated will continue to avoid doing it, so the requirement for more frequent rabies vaccines is nothing more than a penalty handed out to pet owners who do get their animals vaccinated per the law. It is those pet owners who are potentially causing harm to their animals because they are complying with the every 1 or every 2 year vaccine mandate.

Is There a Difference Between the 1-Year and 3-Year Vaccines?
I asked Dr. Schultz if the 1 and 3-year rabies vaccine products are the same. His opinion is most of them are. There is also a 1-year feline rabies vaccine that has no adjuvant, but there is not at this time a similar 3-year product.

I asked Dr. Schultz why there isn't a 3-year non-adjuvanted product. His answer is the adjuvant-free 1-year feline rabies vaccine is new technology. It is a recombinant vaccine that is similar in nature to a modified live vaccine, but there's no live rabies in it. The cat's immune system sees this vaccine as live. The company that developed the adjuvant-free 1-year vaccine did studies that showed vaccinated cats were still protected 100 percent from rabies 3 years later.

However, a problem in the control (non-vaccinated) group of cats (not enough of them died) prevented the USDA from issuing a 3-year license for the vaccine. In a second round of studies, even fewer non-vaccinated cats died, so again, the USDA refused to issue a 3-year license for the product.

With regard to vaccine-associated sarcomas (VAS) in cats, Dr. Schultz believes it's preferable to give the non-adjuvanted 1-year rabies vaccine over the 3-year vaccine containing adjuvants. Whereas the non-adjuvanted 1-year vaccine created no inflammatory response at the injection site (a marker for tumor development), adjuvanted rabies vaccines are known to cause more VAS. So even in genetically predisposed kitties, it is assumed the non-adjuvanted product, even given yearly, is less harmful than the adjuvanted vaccine.

Since it is known that cats are more likely to develop vaccine injection site sarcomas, the direction for feline vaccines is toward non-adjuvanted products.

Adjuvanted products are more likely to cause adverse reactions in general, across all species.

So the overall goal in future vaccine development is to 1) have fewer adjuvanted vaccines and 2) to develop new adjuvants that are less likely to create adverse reactions.

The Vaccine Protocol Dr. Schultz Would Use with a New Puppy or Kitten in His Family
The last question I had for Dr. Schultz was how his vaccination protocol has changed over the years for his own pets and those of family members.

Dr. Schultz feels very confident about the effectiveness of vaccines. He is also a risk taker in his personal life (he rides motorcycles, has a pilot's license), and not everyone (including me) is as comfortable taking risks as he is. So his choices for vaccination of pets must be put into that context.

With that said, there are very few people who know more about veterinary vaccines than Dr. Schultz, so he is really not taking much of a risk with his pets, his children's pets, or his grandchildren's pets with the vaccine protocol he follows.

He does antibody titers on the mother to know the right time to effectively immunize (not just vaccinate) the puppy or kitten for the 3 core viruses. He titers the puppy or kitten 2 or more weeks post vaccine to make sure the animal responded, and as long as the response is adequate, he would probably not re-vaccinate for the rest of the dog's or cat's life. This is a protocol he has followed since 1974.

He would also give a rabies vaccine (which is technically also considered a core vaccine), the frequency of which is not dictated by Dr. Schultz's knowledge of immunology, but is dictated by the law. He gives the first rabies vaccine sometime after 4 months of age, re-vaccinates in a year, and then again in 3 years and every 3 years thereafter. Dr. Schultz reiterates his rabies vaccine protocol is because of the law, not because every 3 year vaccines are necessary immunologically.

The law is not interested in when an animal actually needs another rabies vaccine to be protected – the law simply demands every 1, 2 or 3 year vaccinations with no consideration for whether the animal's body is already immune to the rabies virus thanks to a prior vaccine.

If you choose not to re-vaccinate your pet for rabies, it is your choice, but you should be aware it is also against the law. Neither Dr. Schultz nor I are suggesting you do anything illegal. However, if you choose not to re-vaccinate, be aware your pet is probably protected for life from the virus anyway due to prior rabies vaccination.

If Dr. Schultz's 7-year rabies study can prove the vaccine is good for at least that long, prompting a change in current vaccination laws, then a dog might only receive 2 rabies vaccines in a lifetime.

My Sincere Thanks to Dr. Schultz
I want to point out to all of you that Dr. Schultz is single-handedly changing the face of immunologic veterinary medicine. I am so grateful for the work he does – his effort and his passion – and for helping all of us make better decisions for the animals in our care.

Dr. Schultz, in turn, thanks the veterinarians who've been willing to make changes to their vaccination programs, as well as the vaccine companies that conduct their own studies with their products. Every major veterinary vaccine manufacturer has completed a minimum 3-year vaccine study with the core vaccines, and they have all demonstrated their products provide a minimum of 3-years duration of immunity.

This should say something to any veterinarian out here who is wondering if it's really safe to go 3 years between vaccinations -- as well as any pet owner with similar concerns -- that yes, they can confidently go 3 years, regardless of the product used.