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How Often Should You Vaccinate
Your Cat or Dog?
In part 1 of this 4-part series, Dr. Becker talks
with Dr. Ronald Schultz, a pioneer and expert
in the field of veterinary vaccines. Listen as
the doctors discuss the history of dog and cat
vaccines, and the real reason behind why your
puppy or kitten receives so many vaccines in the
first year of life.
Dr. Becker's Comments:
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
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
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
Canine core vaccines include:
Feline core vaccines:
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
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
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.