Vaccines for
Cats: We Need to Stop Overvaccinating
Lisa A.
Pierson, DVM
Please
click on the links below to read more
about the key issues associated with
vaccines.
Overview
General
suggestions
Side
effects
Vaccine types
Decision-making criteria
- including comments on titers
Conclusion
Supporting
research
Overview
A vaccination is a
preparation of microorganisms
(pathogens), such as
viruses or bacteria, that is
administered to produce or increase
immunity to a particular disease.
There can be no disputing that vaccines
save lives but they also have some
serious side effects which will be
discussed on this webpage.
Please
note that the diseases we most commonly
vaccinate cats for are caused by viruses
- not bacteria. While it is
difficult to induce long-term immunity
to bacterial infections, vaccines
targeted toward viruses are much
more efficient at conferring
long-term immunity in the recipient.
There
are 5 viral diseases that cats are
commonly vaccinated for:
-
herpes (rhinotracheitis) - the 'R'
in FVRCP
-
calici - the 'C' in FVRCP
-
panleukopenia ("feline distemper") -
the 'P' in FVRCP
-
feline leukemia - FeLV
-
rabies
Please
DO NOT vaccinate for FIV (Feline
Immunodeficiency Virus - aka "feline
AIDS"), FIP (Feline Infectious
Peritonitis), bordatella, giardia, or chlamydia.
The
subject of vaccine administration is one of the
most controversial topics in human and
veterinary medical literature, making it
a common area of debate - and
stressful decision-making - among
parents and pet owners.
Given that
this is an area of controversy, I want
to start with a 'food for thought'
question:
How often
are you getting vaccinated for measles,
mumps, chicken pox, tetanus, etc.?
Yearly? Every 3 years?
I doubt
it.
So why aren't more people questioning
the reminder cards that
veterinarians send out asking for the pet
to be brought in for yearly vaccines?
Taking it
one step further, why aren't more
questions being asked about the 'newer'
suggestions to vaccinate cats for FVRCP,
and in some cases, FeLV, every 3 years -
given that we have plenty of data to
show that it is not necessary to
vaccinate cats for these diseases even this frequently?
A cat's immune system is not any more
'forgetful' than a human's immune
system. In other words, there is
no reason to believe that they need to
be vaccinated so often. Their
immune system, to the contrary, has a
very good memory.
For many
years, humans have thought of vaccines
as 'all good and no bad' but that line
of thought cannot be further from the
truth. Given the serious side
effects that can manifest themselves
after a vaccine has been given, people
need to start applying more critical
thought - including a risk-benefit
analysis - when making decisions
about vaccination protocols.
It is very
important to understand that no vaccine
is 100% safe.
However, it is also very important to understand
that vaccines save lives and there can
be no debating that fact.
These two facts, along with other
factors discussed on this page, enter
into every decision we make regarding
how we vaccinate our cats.
I wish
that I felt comfortable saying "ask your
veterinarian for the best advice
regarding the vaccination of your cats"
but I don't.
Unfortunately,
many of my colleagues are simply not
taking the time to carefully peruse the
scientific literature that provides
'duration of immunity' (DOI) data
showing that we are over-vaccinating
many of our pets - even with the
3-year protocols in the case of FVRCP
and FeLV. (Rabies will be
discussed separately.)
This
webpage is not intended to be a
comprehensive discussion on all matters
involving vaccinations but, instead,
will cover some vaccine basics, current
(2010)
WSAVA-VGG (World Small Animal
Veterinary Association - Vaccine
Guideline Group) suggestions, current (2007)
AAFP (American Association of
Feline Practitioners) suggestions,
and my personal views on the subject -
including how I vaccinate my own cats.
Please
note that even some (all?) of the experts who
sat on the panel that came up with the
AAFP suggestions, as well as one
veterinarian who is head of the vaccine
division of a major vaccine-producing
company, do not vaccinate
their own animals as frequently as their
guidelines/suggestions/package label states. (source:
personal communication)
These
veterinarians
acknowledge that the current suggestions/package
labels
do not reflect the fact that
challenge studies have shown a very long
duration of immunity (DOI) -
lifelong, for some
diseases - from just a single,
properly-timed, vaccine.
Unfortunately, it has been hard enough
to get veterinarians to switch from
annual vaccines to the current 3-year protocol
so it is going to be an uphill battle to
get them to vaccinate even less
frequently. Therefore, I do not
see changes in the AAFP suggestions
coming anytime soon.
To put this in perspective, note that
the recommendation to go to a 3-year
vaccine protocol came out of Colorado
State University more than 15 years
ago, yet there are still many
veterinarians administering annual
vaccines.
This
reluctance to change is especially true
of the older generation veterinarians
(myself included having been involved in
this profession for over 30 years) who lived through a
time when the mortality rate from
rabies, distemper, etc., was very high.
Vaccines came along and saved lives - no
question - but it is time to start
paying more attention to the current DOI
studies - some of which have been
available for many years.
I urge the
reader to take the time to do their own
research into this area and not
necessarily rely only on your veterinarian's
recommendations. It will be
up to the reader to decide how they want
to handle vaccine administration in
their own kittens and adult cats for
FVRCP and FeLV.
My goals
in writing this page are to get the
reader to:
-
stop
blindly over-vaccinating their cats
-
apply
more critical thought - including
reading the studies
-
NEVER ALLOW AN ADJUVANT TO BE
INJECTED INTO THEIR CAT
Yes, I am
shouting about the last issue.
There is no good reason for any
veterinarian to inject an adjuvanted
vaccine into any feline patient.
Adjuvants are substances that are
added to vaccines to purposely cause
inflammation at the vaccine site in
order to alert the immune system to its
presence. They are used with
killed vaccines to stimulate a more
robust immune response but can also
cause fatal, aggressive tumors at the
site of vaccine injection. (See
below for a
picture of "Chicken" - a sweet cat who
is battling this cancer.)
DO NOT
assume that your vet is using the safer,
non-adjuvanted vaccines. ASK
before allowing any vaccine to be
administered to your cat.
To repeat
much of what I have said above: There is
nothing in the scientific literature to
support annual vaccination with the FVRCP and Feline Leukemia
(FeLV) vaccines.
It is well-known that:
-
the
vaccines commonly used for cats
confer immunity for much longer
than 1 year - and actually provide
lifelong immunity in most instances
for panleukopenia;
-
adjuvants
contained in killed vaccines put cats
at risk for fatal tumors
(sarcomas);
-
even
the non-adjuvanted FVRCP vaccines
have caused sarcomas, as have the
PureVax vaccines;
-
natural immunity to feline leukemia
is very strong by the time the cat
reaches ~1 year of age; and
-
there may be a link between the
FVRCP vaccine and kidney inflammation.
Please
note that kidney disease is the most
common subject that I consult on and
it is considered by many to be the
number one cause - or at least a very
common cause - of death in our older
cats.
General Vaccine Suggestions
(Please
note that I cannot offer individual
vaccine advice outside of a
phone consultation
to discuss the details of your
situation.)
At the end
of this webpage, please see:
Age and Long-term Protective Immunity in
Dogs and Cats
and
Membranoproliferative glomerulonephritis
possibly associated with
over-vaccination in a cocker spaniel.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Keep in
mind that a vaccine protocol is not a
'one size fits all' issue and that the
medical community is lacking in
definitive research in many areas of
vaccinology. This is why the
WSAVA-VGG, the AAFP, and myself make
suggestions regarding vaccine
protocols - versus etched-in-stone
statements.
To repeat,
there
are 5 viral diseases that cats are
commonly vaccinated for:
-
herpes (rhinotracheitis) - the 'R'
in FVRCP
-
calici - the 'C' in FVRCP
-
panleukopenia ("feline distemper") -
the 'P' in FVRCP
-
feline leukemia - FeLV
-
rabies
Please
DO NOT vaccinate for FIV (Feline
Immunodeficiency Virus - aka "feline
AIDS"), FIP (Feline Infectious
Peritonitis), bordatella, giardia, or chlamydia.
Keep in
mind that if you do decide to vaccinate
for FIV (a very ineffective and
adjuvanted vaccine), your cat will now
test 'positive' since the FIV test
cannot tell the difference between an
infected cat and a vaccinated cat.
FVRCP:
Most
people are familiar with the
abbreviation 'FVRCP' which stands for
Feline Viral Rhinotracheitis (herpes), Calici,
Panleukopenia. FVRCP is a
combination vaccine that includes 3 out
of the 5 vaccines that will be discussed
on this webpage.
This
vaccine can either be modified live
(NON-adjuvanted) or killed (adjuvanted).
The route of delivery can be either
injectable or intranasal.
Only use a modified live (NON-adjuvanted)
- never a killed (adjuvanted) - FVRCP
vaccine, with injectable (not
intranasal) being the preferred route of
administration in most, but not all, instances.
To clarify
- all modified live vaccines (MLV) are
NON-adjuvanted.
Herpes
and calici: These are the upper
respiratory viruses that can
cause watery/swollen/ulcerated eyes
(mainly herpes), sneezing, nasal
congestion, and oral ulcerations. The severity of
illness ranges from very mild to
severe but the mortality rate is
very low.
Unfortunately, as is true for the 'common cold'
in humans, there is no 100% effective
vaccine for herpes and calici in the
cat. One reason is that these
viruses mutate (change) frequently and
there are many different strains.
The vaccine will not prevent infection
but will, hopefully, lessen the severity
of clinical signs.
Panleukopenia:
This is a highly contagious virus that
infects the intestines causing
severe bloody diarrhea and vomiting.
This disease has a very high
mortality rate.
Do not
let your kitten go
unprotected from panleukopenia.
This virus can cause a very cruel death.
My
suggestions:
Kittens:
Vaccinate
kittens with FVRCP twice starting at 8-9
weeks of age with the second, and final
kitten
vaccine, administered when the kitten is
no younger than 16 weeks of age.
The AAFP
guidelines state that you can start this
vaccine when the kitten is as young as 6
weeks of age but, unless there is a very high
index of risk, I would definitely not vaccinate a
kitten this young.
We wait
until the kitten is at least 16 weeks
old to receive his last kitten shot
because the antibodies he got from
nursing on his mother will have
decreased to a low enough level that his
own body can respond to the vaccine in
order to make his own antibodies.
(Maternal antibodies within the kitten
can
'tie up' the vaccine before his body has
a chance to respond to it.)
The AAFP
and WSAVA-VGG
guidelines suggest giving the FVRCP every 3-4
weeks until the kitten is 16 weeks of
age. This is to try to vaccinate
the kitten the minute his maternal
antibody level wanes to a low enough
level to allow him to respond to the
vaccine. That way, there will be a
minimal gap between the time his mother's
antibodies stop protecting him and the
time when he can start making his own
antibodies.
That
said, I would rather not give this many
vaccines to a kitten. Unless there
is a high index of risk, I prefer to limit it to 2
vaccines total for the kitten series.
If you read the AAFP
guidelines, there is the potential for
administering 4 vaccines in the kitten
series. Given the fact that the FVRCP vaccine has been
proven to cause
kidney inflammation (nephritis), I am not
comfortable following their suggestions.
See Membranoproliferative glomerulonephritis associated with
over-vaccination in a cocker spaniel
puppy at the bottom of this webpage.
The above
case involved an owner who, without
veterinary supervision, vaccinated his
puppy 7 times - 1 time per month.
The puppy died at 7 months of age from
kidney failure due to kidney
inflammation. The two most
striking facts/comments in this case
report are:
"In addition, antigens
in the complexes were similar to the
vaccine antigens in the DHLPP vaccine,
suggesting
that the glomerulonephropathy in this
puppy
was secondary to frequent and
unnecessary vaccination."
and....
"Further studies are
required at
this time to determine the role, if any,
that recent
past and current vaccine protocols play
in the
development of protein-losing
nephropathies."
The last
statement is very important considering
the fact that chronic kidney disease is
the most common subject that I consult
on and that 2/3 of the kidney cells must
be non-functioning before we see any
elevation in blood markers such as BUN
and creatinine. Therefore, we
certainly may be damaging kitten
kidneys by giving them 4 vaccines by the
time they are 4 months old but not be
aware of it.
Put
another way - if 7 vaccines in 7 months
resulted in the death of a puppy, then I
am not comfortable with 4 vaccines
within 10 weeks for a kitten.
Young
adults:
The AAFP
and WSAVA-VGG
guidelines suggest giving a booster FVRCP 1 year
after the last kitten vaccine - i.e. -
when the cat is ~ 16 months of age.
However, if the kitten responds as he
should to the kitten series, this
booster should not be needed. The rationale behind the
1 year booster shot is to cover any
kitten that did not properly respond to
the kitten series.
Reasons
why a kitten may not fully respond to a
series of vaccines as a kitten and would
benefit from a 1 year booster are:
1)
The last kitten shot was given when he
was younger than 16 weeks of age.
2)
Maternal antibodies hung on longer than
16 weeks and interfered with his immune
system's ability to respond to the last
vaccine. (We have good studies
showing that the maternal antibody
levels are low enough in most kittens to
allow them to respond to a vaccine by
the time they are 8-12 weeks of age so
this is an improbable scenario.)
3) The
kitten was in poor health when
vaccinated and did not respond properly.
(Vaccines should never be administered
to sick animals but, unfortunately,
unhealthy animals are vaccinated more
often than you may think.)
4) The
vaccine was of inadequate immunogenicity
which means that the vaccine was damaged
in terms of its efficacy. This could
happen due to a problem within the
manufacturing process or because of poor
handling of the vaccine after it left
the manufacturing plant.
Note that
some cats are genetically
'non-responders' and never will respond
to a vaccine no matter how many you give
them. In these rare cases, giving
a booster vaccine 1 year after the last
kitten vaccine would be of no benefit.
Deciding
to give a booster vaccine 1 year after
the last kitten vaccine, or not, is a
judgment call.
The older a kitten
is (past 16 weeks of age) when he
receives his last kitten shot, the less
inclined I would be to give a booster
shot 1 year later.
This is because the
older he is, the more mature his immune
system is - and better able to respond - and the less chance there will
be for the maternal antibodies to be at
a high enough level to interfere with
his ability to respond to a vaccine.
Another
option would be to test his
titer
(antibody level) to panleukopenia (not
herpes or calici) to help you make a
decision. (More on
titer testing below.) This is what
I would personally opt for.
Adults:
I do not repeat
the FVRCP vaccine past the kitten shots
- or past the 1-year booster as
discussed above.
We must
stop vaccinating with FVRCP every year.
Taking it
one step further,
I also disagree with the AAFP guidelines
which suggest giving the FVRCP every 3
years since the risks outweigh the
benefits.
Why?
Consider
the facts that enter into the
risk-benefit analysis:
1) A single, properly-timed, FVRCP vaccine
confers life-long immunity to
panleukopenia (the most serious
disease among the 3 that the FVRCP
targets) in the vast majority of cats.
Those very few cats that may not be protected are
considered to be 'non-responders' and
giving them more vaccines is unlikely to
help.
2) Herpes
and calici vaccines lack the ability to induce
complete protection. At best, they
will only reduce the severity of some
symptoms but will not prevent infection
with these viruses and will not protect
the recipient from all symptoms of
disease.
3)
Herpes and calici viral infections do
not have a high mortality rate.
Death from these viruses is extremely
rare and, if it did occur, it would most
likely happen in kittenhood.
4) Even
though a non-adjuvanted FVRCP vaccine is
much less likely to cause a sarcoma,
sarcomas have been noted with these
vaccines.
5) Studies have indicated that there may be a link between the FVRCP vaccine and kidney disease.
My own cats are over 10 years of age and
have not been vaccinated with FVRCP
since their properly-timed kitten
series.
If you
rescue/adopt an altered
(spayed/neutered) adult with an unknown
vaccine history, I strongly suggest
running a titer for panleukopenia rather
than vaccinating blindly. If the
cat is spayed or neutered, chances are
she or he was vaccinated as a kitten.
However, the age at which he received
his last kitten vaccine (past 16 weeks
of age?) will not be known
so the decision to administer a vaccine,
or not, is a judgment call. This
is a situation where titer testing can
help out.
As odd as
it may sound, if I rescue a neutered
adult male cat with a fairly good size
(empty) scrotal sac, I assume (rightly
or wrongly....) that he
was most likely not neutered before the
age of 16 weeks. (Male cats that are
neutered very young have a very flat
scrotal sac.) Given that most
cats are vaccinated when they are
neutered, this gives us a hint (and
nothing more than that) that the cat may
very well have received a vaccine past
the age of 16 weeks.
Also, keep
in mind that many of these
stray cats have been 'travelling the
streets' and may have a good dose of natural
immunity to some feline diseases
although that cannot be counted on
definitively.
The AAFP
guidelines call for a series of 2 FVRCP
vaccines to be given 3-4 weeks apart to
an adult with an unknown vaccination
history but the WSAVA-VGG recommends
that only 1 FVRCP vaccine be given with
a booster vaccine 1 year later.
In lieu of
this 1 year booster, I would suggest
titer testing.
Studies have shown that cats
over 16 weeks of age
with a healthy immune system respond
very well to just 1 FVRCP vaccine.
Robbie
Feline Leukemia (FeLV):
Feline
leukemia, that results from the
feline leukemia virus, is a
complicated disease. It
typically attacks the bone marrow of
the cat but cats vary in their
response to the virus. Some
cats clear the virus from their
system and become FeLV 'negative',
some cats live for many years with
the virus in their body but are not
symptomatic, and some cats become
ill and die within a few years of
becoming infected.
FeLV is
NOT highly contagious and its
transmission requires prolonged contact
with an infected cat. Natural
immunity is very strong in most cats by
the age of 1 year. AAFP guidelines
suggest
vaccinating all kittens but the vaccine
is recommended in adults only if
they will be in contact with a known FeLV positive cat - which would be a
very rare situation.
I
disagree with the recommendation to
vaccinate all kittens. None of my
own cats have ever been vaccinated for
FeLV - not even as kittens - since they
reside indoors and will not be in
contact with a FeLV positive cat.
My
suggestions:
Do not
vaccinate kittens for FeLV unless your
kitten is going to be outside (rarely a
safe place to be for any kitten or cat)
or is going to be housed with an FeLV
positive kitten or cat.
Do not
vaccinate adult cats for FeLV - even if
they have access to the outdoors - since
natural immunity to this disease is very
strong by the time the cat is ~1 year of
age. If an adult cat is going to
be living with a FeLV positive cat, then
vaccination should be considered.
If you do
choose to vaccinate for FeLV, ONLY use
the Meriel PureVax FeLV vaccine
which is NON-adjuvanted. All other
FeLV vaccines are killed and contain
adjuvants which
should never be injected into any cat.
Willie
Rabies:
This is a very serious disease with
100% mortality in animals and
humans. (There is only 1 known
human survivor and I don't know of
any animal survivors.) Since
humans can contract rabies from
animals, including cats, vaccinating
cats for rabies is required by law
in some areas of the country.
Any cat that is exposed to the
outdoors, or any indoor cat that
could possibly come in contact with
a bat, should be vaccinated for
rabies.
Bat rabies
is the most common strain to infect
humans. Bats can live in attics,
fly down chimneys, come in through
windows, and 'indoor-only' cats have
been exposed to rabid bats on balconies.
There is
only one suitable rabies vaccine and
that is Merial's PureVax rabies
vaccine. This is a NON-adjuvanted
vaccine.
DO NOT ALLOW AN ADJUVANTED RABIES
VACCINE TO BE USED.
Unfortunately, the PureVax rabies
vaccine only carries a 1-year rating
even though 2 studies have shown that it
protects cats for much longer.
This is in contrast to the more
dangerous adjuvanted rabies vaccines
that carry a 3-year rating.
Merial conducted 2 well-run studies
showing that their PureVax rabies
vaccine protected all study participants
from a challenge with the rabies virus 3
years later. However 1 'control'
(non-vaccinated) cat in each study did
not die from the rabies challenge.
Therefore, Meriel was not granted a
3-year license for this vaccine.
Good science shows that this vaccine is
protective for at least 3 years but
legally, it is only labeled for 1 year
protection.
Because
rabies is such a serious disease and is
transmissible to humans, the laws are
very strict in this area. If your
cat bites someone and it has been longer
than 1 year since receiving a PureVax
vaccine, legally he is considered to be
'not current' on his vaccines and he may
have to go into a quarantined
environment for 10 days. This is
often done in a veterinary clinic but,
occasionally, the cat is allowed to
spend the time in his own home.
If your
cat is not vaccinated at all and he
comes in direct contact with a wild
animal that is not available for rabies
testing, quarantine for up to 6 months
may be required. How strictly this
is enforced varies from state to state.
As
counter-intuitive as it may sound, it is
much safer to administer a PureVax
vaccine yearly than it is to inject an
adjuvanted rabies vaccine every 3 years.
That said,
I do not recommend yearly PureVax
administration unless your local
laws mandate rabies vaccinations for
cats, or your cat is at risk
for rabies infection, or your cat is an
aggressive biter and you fear having to
deal with a quarantine situation.
My own cats are
not vaccinated for rabies since I live
in an area where rabies is not common,
my cats have never been outside and
never will step 'paw' outside, and I am
confident that a bat cannot enter my
home. My cats are also not allowed
out on a balcony due to 'high rise
syndrome'...ie...it is very common for
cats to fall off of balconies resulting
in death or severe injury.
If your
cat has health issues and you live in an area where
rabies vaccination for cats is
mandatory, ask your vet for a health
waiver. Keep in mind that only healthy cats are to receive
vaccines and it states as such on
every bottle of every vaccine.
The
PureVax literature states that you can
administer 1 vaccine as early as 8 weeks
of age, followed by a second vaccine 1
year later.
Keep in
mind that the older the kitten is when
he is vaccinated, the more efficiently
his immune system will be able to
respond. Therefore, I would always
wait until the kitten is at least 16
weeks of age before receiving a PureVax
rabies vaccine. Of course, the
kitten needs to be kept indoors at all
times until he is properly vaccinated.
Please
note that fatal sarcomas have developed
secondary to the administration of the
PureVax rabies vaccine so this vaccine
is not without risk. However, the
chance of a tumor occurring from a
PureVax vaccine is lower than it would
be with an adjuvanted vaccine.
Dusty and Dylan
Sarcomas
These are
highly invasive, aggressive/malignant cancerous
tumors that are often fatal within
months of appearing. (See
"Chicken"
below.)
They are
most commonly associated with vaccine
adjuvants but can also form at the site
of any injection that causes local
inflammation - including
the non-adjuvanted, modified live FVRCP
vaccines, the PureVax line of vaccines,
and drugs like Program (for fleas),
Droncit (for tapeworms), and
Convenia (an
injectable
long-acting antibiotic that is being
over-used and abused).
Adjuvants are substances that are
added to vaccines to purposely cause
inflammation at the vaccine site in
order to alert the immune system to its
presence. They are used with
killed vaccines to stimulate a more
robust immune response.
Unfortunately, this inflammation can lead to sarcomas.
The
discovery that vaccine adjuvants can
cause sarcomas led to the acronym VAS
(Vaccine Associated Sarcoma). Some
people have tried to change this to ISS
(Injection Site Sarcoma) because
sarcomas can form in response to
anything that causes inflammation of the
area under the skin but the bottom line
is that sarcomas were rare prior to
the advent of adjuvants.
(That
said, I am still very careful about
injecting anything into a cat -
given their tendency to develop cancer
at the site of any inflammation - if
there is a safer alternative. See
this article on Convenia.)
Sarcomas
need to be aggressively treated - at
great expense - if one is to try to save
the patient's life.
Unfortunately, the PureVax line of NON-adjuvanted
vaccines are more expensive than the
adjuvanted vaccines. Therefore,
most shelters and many veterinary
clinics still use the more dangerous
adjuvanted vaccines.
DO NOT
assume that your veterinarian uses the
safer vaccines.
ASK - before
allowing any vaccine to be injected into
your cat.
"Chicken"
is a special kitty that ended up with a
VAS after an adjuvanted rabies shot was
given in the scruff area. In
addition to aggressive surgery, she has
had to go through radiation and
chemotherapy treatments.
This
picture was taken 12/2/10 after the bulk
of the tumor was removed. Please
note that these are very aggressive
tumors with 'tentacles' that run deep
into the tissues. Therefore, it is
almost impossible to remove the entire
tumor. Click
here to follow Chicken's blog.
Please
note: NO vaccine (adjuvanted or
non-adjuvanted) is to be
given in the scruff area under any
circumstance. They are to be given
as low in a limb as possible. This
is to allow for limb amputation if a VAS
occurs.
In 1997, the AVMA (American Veterinary
Medical Association) came out with the
strong recommendation to never use the
scruff area for vaccines.
Evidently, the veterinarian who
administered Chicken's adjuvanted rabies
vaccine either did not take this
recommendation seriously or was not
keeping up on his continuing education.
In addition to using the wrong location,
an adjuvanted rabies vaccine was
used instead of PureVax and Chicken is
paying a high price for these mistakes.
Chronic Kidney Disease (CKD)
As already
mentioned, this is the most common subject that
I consult on and it is upsetting to
see so many domestic cats end
up dying from kidney disease when it
is not that prevalent in wild cats.
I understand that cats in the
wild do not typically live as long as our
little furry buddies but I still
cannot accept that natural aging is
the only factor involved in this
disease process.
Why do so many cats end
up in kidney failure?
The answer
- or at least, part of the answer - may
lie in the fact that we have been
over-vaccinating cats for many years.
Studies
have demonstrated a possible association
between the FVRCP vaccine and
interstitial nephritis which is the
fancy term for
kidney inflammation.
Here is an
excerpt from one of those studies: (See below for a 'plain
English' summary.)
"The
Center for Companion Animal Studies at
Colorado State University has shown that
cats vaccinated with FVRCP vaccines
grown on Crandell-Rees Feline Kidney (CRFK)
cell lines can develop antibodies to
renal (kidney) proteins, and that cats
hypersensitized to CRFK cell lysates can
develop interstitial nephritis.
The
immunodominant antigens to which
antibodies are formed in these cats are
α-enolase and Annexin A2, both of
which are linked to autoimmunity and
renal disease in humans.
Recently,
we have shown that cats administered
FVRCP vaccines parenterally (i.e.
injectable) have higher levels of
circulating antibodies to these antigens
than do cats who were administered a
FVRCP vaccine via intranasal
administration."
Now...in
plain English:
The
viruses used to make vaccines need to be
grown in what is called a "cell
culture". The cells used to make
the FVRCP vaccine are feline (cat)
kidney cells.
When these
kidney cells are injected into the cat
(along with the vaccine), his immune
systems views them as foreign and makes
antibodies against them.
Unfortunately, those antibodies do not
know the difference between the injected
kidney cells and his own kidney tissue
resulting in a potential autoimmune 'attack'
on his kidneys. ('Auto'
means 'self''.)
Most
people have heard of Lupus. Lupus
is an autoimmune disease
most commonly seen in humans.
In essence, the FVRCP vaccines have the potential to stimulate
a Lupus-like reaction in the recipient. More studies are needed to determine what role vaccines may play in causing or contributing to feline kidney disease.
Monique - TLC Adoptions rescue in kidney
failure
Allergic/Anaphylactic reactions
An
allergic reaction, in simplistic terms,
it is an overreaction by the immune
system to a foreign substance that
enters the body.
An
anaphylactic reaction is a very severe
allergic reaction that affects the
entire body and is life-threatening -
even if treated promptly.
The
typical 'shock' organ of the cat is the
lungs. If the reaction is severe
enough, the signs can include coughing,
difficulty breathing, coughing up blood,
collapse, and death.
Another
'shock' organ of the cat is the
intestinal tract. Cats can exhibit
mild to severe vomiting and diarrhea -
sometimes bloody.
Other
serious reactions can involve blood
vessels (vasculitis), red blood cells
(Immune Mediated Hemolytic Anemia),
platelets (Immune Mediated
Thrombocytopenia), and any organ of the
body.
'Milder'
allergic reactions can cause a swollen
face, swollen limbs, and itching.
Foreign
substances that can cause
allergic/anaphylactic reactions include
all vaccines, all drugs, foods,
etc.
Vomiting,
diarrhea, lethargy, fever, anorexia,
lameness, neurologic abnormalities, local swelling and soreness at
vaccine site
All of
these negative clinical signs can be
seen secondary to the administration of
vaccines.
Mindy and Mikie
Vaccine Types
There are
4 main categories of vaccines:
Killed
Do not
use.
All killed
vaccines are adjuvanted
and may cause malignant
tumors.
All FeLV vaccines, except
for PureVax, are killed.
Some FVRCP vaccines are
killed.
Killed
vaccines do not stimulate the immune
system as efficiently as modified live
vaccines.
Modified live
(MLV)
MLV stands
for Modified Live Virus. They are
all NON-adjuvanted. The viruses
contained in these vaccines are not
killed but are attenuated (blunted) so
that they will replicate in the recipient but,
hopefully, will not cause disease.
Most, but not all, FVRCP vaccines are modified
live.
'Reverting
to virulence' means that the virus
contained in the vaccine is now
infective enough to cause disease. This
is a rare risk of using MLV vaccines.
Note:
In 1999, I was involved in a situation
where several kittens in a group died
from panleukopenia post vaccination with
a MLV FVRCP vaccine. The vaccine
was from a leading vaccine manufacturing
company and after speaking with their
head veterinarian, it was determined
that the vaccine may have reverted to
virulence.
This means
that the vaccine could have caused the very
disease we were trying to protect these
kittens from. Since MLV vaccines
do carry this risk, I try to limit the
kitten series to 2 MLV vaccines.
Intranasal
(IN)
Intranasal
vaccines are also modified live viruses
and all are NON-adjuvanted. They
are administered via the nose and eyes.
I do not use them for several reasons.
The following comments pertain to the
intranasal FVRCP vaccine - keeping in mind that
the most important virus among the 3
that any FVRCP vaccine targets is
panleukopenia:
1)
The route of infection for panleukopenia
is oral, not via the respiratory tract.
Intranasal vaccines are better at conferring
immunity for respiratory viruses and are
less effective than an injectable MLV
for stimulating immunity to
panleukopenia.
2)
There are no DOI challenge studies
for panleukopenia post-intranasal
vaccination like there are for the MLV vaccines.
3)
Even though they may be more efficacious
for the herpes and calici viruses, they often
cause sneezing and watery eyes and the owner needs to be aware
of this.
Our rescue group tried using these
vaccines and it was a disaster because
our kittens had to sit out from
adoptions for about 2 weeks due to
sneezing and watery eyes.
4) On a
positive note, intranasal vaccines cannot cause
a Vaccine Associated Sarcoma and
they have been shown to cause NO
kidney inflammation. However,
even in light of these 'pluses' I am not
comfortable using them to protect
kittens against panleukopenia.
5)
In some situations (catteries and
shelters with a severe herpes/calici
problem), the IN vaccine that
contains only the herpes and calici
viruses but not panleukopenia virus is
of value since it stimulates a local
mucosal (the lining of the respiratory
tract) immunity very quickly and is not
affected by maternal antibodies.
Therefore, it can be given to kittens
younger than the traditional 8 weeks of
age.
Recombinant
Merial's
PureVax rabies (1 ml dose) and feline
leukemia (0.25 ml dose) vaccines are
recombinant vaccines which means they
contain only a portion of the genetic
material of a pathogen (virus).
Therefore, reversion to virulence (able
to cause disease) is impossible.
The
PureVax FeLV vaccine uses a very low
volume (0.25 ml) and it is injected
intradermally (within the skin) versus
under the skin. No needle is used
but, instead, a special Vet Jet
transdermal injection system is used
Although I
have not seen any literature on the
negative reaction rate, I am going to
assume that the recombinant vaccines
will be less apt to cause an
anaphylactic reaction because they
contain fewer potential allergens.
They also
do not replicate in the recipient and
there is no reason to believe that they
cause kidney inflammation.
To
clarify: Merial makes a PureVax
FVRCP vaccine but it is not a
recombinant product. It is a
modified live vaccine just like other
manufactures make.
Recombinant vaccines are the safest type
available. While they can
cause sarcomas (in my reading I came
across a reference to two cases), they
are much less likely to do so when
compared to a killed/adjuvanted vaccine.
Decision-Making Criteria
(Some of
this dialog is also stated in the above
sections.)
What
are some of the factors that
influence our decisions regarding which
vaccines to use and at what frequency?
I will say
at the outset of this discussion that my
indoor-only cats (all over 10 years of
age) have not been vaccinated since they
were 4-6 months of age. They have
never set their paws outside and never
will - barring a catastrophic event.
My barn
cat (13 years of age) received his last
FVRCP vaccine at the age of 5 or 6
months and received a FeLV series at
around 6 months of age (before
we knew how dangerous adjuvants can be;
PureVax was not around at that time),
and is vaccinated with PureVax rabies
vaccine approximately every 3-4 years.
Please
note that I do not administer more FVRCP
vaccines to my barn cat than I do to my
indoor-only cats. This is because
the panleukopenia immunity from the
FVRCP vaccine lasts for life in the vast
majority of cats and I do not feel that
the minimal amount of protection the
herpes and calici fraction may
provide is worth the downsides of the
vaccine. Remember, it is all about
risk-benefit analysis.
Now,
having confessed my cats' minimal
vaccine history, I will state that what
is 'right' for me and my cats, may not
be 'right' for you and your cat(s).
Issues to
consider:
-
age of patient
-
risk of exposure to the disease in
question
-
prevalence of the disease in the
environment
-
consequence of the infection
-
overall
health of the patient
-
vaccine efficacy
-
DOI studies (Duration of Immunity)
for the vaccine
-
vaccine properties (adjuvanted/non-adjuvanted,
etc.)
-
titer
testing
-
owner's comfort level
Let's
start with the last one - the owner's
comfort level.
This
certainly does not sound like a very
scientific factor but it is an important
issue to consider. Given the fact that
all
foreign substances do have side effects
when introduced into any living being, I
would be a hypocrite if I did not
mention the owner's feelings since my
own comfort level is tested anytime I
decide to inject anything into the
body of my own cats or that of my
patients.
Now having said that, we
can't throw the baby out with the
bathwater and not vaccinate at all otherwise, our cats (and
possibly their humans in the case of
rabies) may suffer for it.
Now, for the science:
-
Age of the patient:
Maternally-acquired
immunity is an important concept to
understand. When a kitten nurses
from his mother, the first milk that she
produces (colostrum) is rich with antibodies to fight the various
diseases that the mother has been
exposed to either naturally from her
environment or from any vaccines that
she has received prior to giving birth.
(Hopefully all owned cats have been
spayed/neutered so as not to
contribute to the tremendous
overpopulation problem in this world.
Therefore, most cats that have given
birth are unowned or wild (feral) cats
that have not been vaccinated and only
carry antibodies to diseases present in
their own environment.)
Maternal antibodies acquired by the
kitten inhibit his
ability to fully respond to a vaccine.
These antibodies diminish over time and
by 16 weeks of age, are at a low
enough level in nearly all kittens to allow
their immune system to adequately
respond to a vaccine. (Most
kittens can respond to a vaccine by 8
weeks of age but we 'pad' it a bit to
cover those with longer-lasting maternal
antibodies.)
Therefore, the last vaccine in the
'kitten series' should be given when the
kitten is at least 16 weeks of age.
Current
conventional protocol states that you
can start to vaccinate kittens as early
as 6 weeks of age but it would be a very
rare situation that would cause me to
start vaccinating a kitten at such a
young age.
I find
that most kittens that are presented for
vaccination are kept indoors and are well-isolated from disease.
If the kitten resides in a protected
indoor environment, I feel comfortable
starting the vaccine series later than
the conventional protocol calls for.
This means that I may not start a
kitten's vaccines until he is ~10 weeks
of age, with the second vaccine given at
16 weeks of age.
Keep in
mind that even though my barn cat is
outside and technically has a higher
risk of exposure, given the duration of
immunity of the panleukopenia vaccine,
he is not vaccinated with FVRCP any more
frequently than my indoor-only cats.
-
Consequence of the infection:
An infection with herpes or calici
is far less serious than an
infection with panleukopenia or
rabies. Also, keep in mind that the
herpes and calici vaccines do not
protect the recipient from infection
since their efficacy is not as
strong as the vaccines for
panleukopenia and rabies. Herpes and
calici vaccines only lessen the
severity of symptoms but will not
prevent infection. This is an
important fact as it pertains to the
risk-benefit analysis. (The
risk of sarcoma, kidney
inflammation, etc., outweigh the
small, if any, benefit of
re-vaccination.)
-
Health of the patient:
Vaccines are to be administered only
to healthy patients.
-
Previous vaccine reactions:
All past vaccine reactions - no
matter how minor - must be taken
into consideration when making
future vaccine decisions. I
will not re-vaccinate any cat that
has had an allergic reaction since
the next time may bring on a more
serious reaction.
-
Vaccine efficacy:
Vaccines vary in their ability to
confer strong immunity within the
patient. Some vaccines, such
as the FIV (Feline Immunodeficiency
Virus) vaccine are not very
effective at stimulating immunity in
the recipient. In addition to
this issue, the FIV vaccine is a
killed product which means it contains
an adjuvant. Therefore, it should not be
administered to any cat, in my
strong opinion, due to the risk of
VAS.
As noted
above, Herpes
and calici vaccines are also lacking in
the ability to induce complete
protection. At best, they will
only reduce the severity of some
symptoms but will not prevent infection
with these viruses and will not protect
the recipient from all symptoms of
disease. The risks outweigh the
benefits in most situations.
-
Duration of immunity (DOI):
The duration of immunity (how long a
vaccine protects the recipient)
varies with each disease/vaccine
and, of course, with each patient. However, one vaccine
that we do have strong data for is
the panleukopenia vaccine
which is a very good thing
considering how contagious this
fatal disease is.
From two
different
studies, we know that the panleukopenia
vaccine confers immunity for at least
7.5 years (the study was stopped at that
point) and most immunologists feel
that the vaccine lasts for life in the
vast majority of cats. If a cat
falls into the rare category of not
being protected for life, it is thought
that this cat is a
'non-responder' and would fail to
respond even if further panleukopenia
vaccines were given.
-
Vaccine properties:
As I
have stated many times, do not ever
use an adjuvanted vaccine.
-
Titers: Note that
titer testing is only done for
panleukopenia and
rabies (for international
shipping) and not for herpes
and calici.
Think of the immune system as a 'gun'
and antibodies as 'bullets' for the gun.
A titer measures the amount of
antibodies for a specific disease that
are currently circulating in the
blood stream of the body. This
sounds like a great test but the
information we get from titer testing is
only part of a much bigger picture.
Notice
that I emphasized the word "current" in
the paragraph above. This is
because of 'memory cells' which are
cells in the body that titer testing
cannot measure. Memory cells are
primed by a previous natural exposure or
vaccination to a pathogen (virus,
bacteria, fungus, etc.) and are ready to
quickly (within hours) produce more
antibodies the moment the body is
exposed to the invader again.
These cells do not produce antibodies -
and therefore, do not contribute to the
titer level - until the body is attacked
by the pathogen.
Antibodies are not the only type of
'bullet' that the immune system uses.
There is another type of 'ammunition'
called cell mediated
immunity
(CMI) which is a very important arm of
the immune system that, unfortunately,
we cannot measure with any commercially
available test - including a titer test.
Given the
above, it is obvious that titer testing
has some severe limitations when being
used to assess the status of a patient's
immune system.
So when
may titer testing be helpful?
As
discussed above, two examples are:
1) to
decide if you want to give the 1-year
booster after the last kitten vaccine
2) to
decide if you want to vaccinate an
altered adult cat that came to you with
an unknown vaccine history
If an UNaltered stray cat ends up on your
doorstep, chances are that he or she has
not been vaccinated - and should receive
a vaccine now.
Titer
interpretation:
If a cat
shows any titer at all, this means that
he has either been vaccinated in the
past (and responded to that vaccine) or
he has been naturally exposed to the
disease.
According
to the World Small Animal Veterinary
Association Vaccine Guidelines Group (WSAVA-VGG),
a positive test result would lead to
the conclusion that revaccination is not
required.
Note that
a low (versus high) titer does not
necessarily mean the cat is unprotected
since memory cells and cell mediated
immunity are, in all probability,
present in full-force. This is
very important to understand because the
advent of titer-testing has led to
unnecessary revaccination of many
patients just because they came up low
on their titer test.
A negative
titer means that the cat may, or may not
be, protected. The WSAVA-VGG
recommends vaccinating these cats while
acknowledging that these patients
may be fully protected and not need to
be vaccinated. They are,
understandably, taking a 'better safe
than sorry' approach since panleukopenia
is such a serious disease.
If a cat
with a negative titer is subsequently
vaccinated (with a properly manufactured
and handled vaccine) and has his titer
re-checked with another negative result,
this patient would fall into the
'non-responder' category and should not
be vaccinated again.
Tyke
Conclusion
I wish
that I could tell you that there are a
straight-forward, clear-cut answers for
all decisions involving the vaccination
of our cats but there are
simply too many variables involved to
make this a reality.
As noted
above, please understand that I cannot
offer any advice via email. If you
wish to discuss your personal situation,
I am available for
phone consultations.
In
closing, I would like to see less money
being spent on over-vaccination of our cats
and more money being spent on dental
health care which will be the subject of
my next webpage.
Preview:
Please consider
brushing your cat's teeth since it
is the very best way to maintain their
dental health.
And please
do not subject your cat to
anesthesia-free dental cleanings which
provide very little benefit since the
problems are under the gum line
and these 'awake' cleanings only serve
to stress your cat and your pocketbook
for very little, if any, benefit.
(No cat
is going to let a human probe and clean
under their gum line.)
These
anesthetic-free cleanings simply result in is a
false sense of security leading the cat
owner to believe that they have
adequately addressed their cat's dental
needs.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Supporting research
regarding vaccinations
- 2 abstracts:
I put
some text in bold. Please note
that Dr. Ron Schultz is one of the
leading experts in immunology and is
highly respected.
J Comp
Pathol. January 2010;142S1(0):S102-S108.
R D Schultz1, B Thiel, E Mukhtar, P
Sharp, L J Larson
1 Department of Pathobiological
Sciences, School of Veterinary Medicine,
University of Wisconsin-Madison,
Madison, Wisconsin, USA.
Abstract:
Vaccination can provide an immune
response that is similar in duration to
that following a natural infection. In
general, adaptive immunity to viruses
develops earliest and is highly
effective. Such anti-viral immune
responses often result in the
development of *sterile immunity and
the duration of immunity (DOI) is often
lifelong.
In
contrast, adaptive immunity to bacteria,
fungi or parasites develops more slowly
and the DOI is generally short compared
with most systemic viral infections.
Sterile immunity to these infectious
agents is less commonly engendered.
*Dr Pierson's comment: "Sterile
immunity" refers to the immune system
preventing infection with the
offending agent. "Non-sterile
immunity" refers to the fact that the
pathogen can still infect the body
(herpes and calici, for instance) but
the clinical signs will not be as severe
in a vaccinated animal when compared to
an unvaccinated animal. End
comment.
Old
dogs and cats rarely die from
vaccine-preventable infectious disease,
especially when they have been
vaccinated and immunized as young adults
(i.e. between 16 weeks and 1 year of
age). However, young animals do die,
often because vaccines were either not
given or not given at an appropriate age
(e.g. too early in life in the presence
of maternally derived antibody [MDA]).
More animals need to be vaccinated to
increase herd (population) immunity. The
present study examines the DOI for core
viral vaccines in dogs that had not been
revaccinated for as long as 9 years.
These animals had serum antibody to
canine distemper virus (CDV), canine
parvovirus type 2 (CPV-2) and canine
adenovirus type-1 (CAV-1) at levels
considered protective and when
challenged with these viruses, the dogs
resisted infection and/or disease.
Thus,
even a single dose of modified live
virus (MLV) canine core vaccines
(against CDV, cav-2 and cpv-2) or MLV
feline core vaccines (against feline
parvovirus [FPV], feline calicivirus [FCV]
and feline herpesvirus [FHV]), when
administered at 16 weeks or older, could
provide long-term immunity in a very
high percentage of animals, while also
increasing herd immunity.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Ortloff A,
Moran G, Olavarria A, Folch H. J SMALL
ANIM PRACT
51:499-502, 2010.
This
report described a clinical case of
membranoproliferative
glomerulonephritis (MPGN) in a
young dog. The 7-month-old male cocker
spaniel
presented to the veterinary clinic with
vomiting,
diarrhea, lethargy, and anorexia. The
puppy had
been previously healthy with no prior
disease,
drug treatment, or toxin exposure.
However, the
puppy had been vaccinated by the owner
(without
veterinary direction) a total of 7 times
(once per
month) with a distemper/hepatitis/leptospirosis/
parainfluenza/parvovirus (DHLPP)
vaccine.
The puppy was severely dehydrated on
clinical
presentation and demonstrated pale
mucous
membranes, oral ulcerations, halitosis,
and
abdominal pain. Several diagnostic
procedures
were performed, and ultrasonography
revealed
loss of renal architecture, increased
cortical
echogenicity, and bilaterally decreased
kidney
size.
Complete blood count and serum
biochemical
values were consistent with renal
disease,
including anemia, severe azotemia,
hyperphosphatemia,
and hypoalbuminemia. Urine culture
was negative. The puppy was aggressively
treated for renal failure, including
peritoneal
dialysis, but died 3 days after hospital
admission.
Necropsy was authorized, and revealed ascites,
retroperitoneal and abdominal edema,
small
pale kidneys, and kidney morphologic
changes
consistent with glomerulonephritis.
Electron
microscopy and immunohistochemical
testing
demonstrated the presence of deposits in
the
glomerular subendothelial spaces and the
basal
membrane; this was consistent with
antigenantibody
immune complexes.
In addition, antigens
in the complexes were similar to the
vaccine antigens in the DHLPP vaccine,
suggesting
that the glomerulonephropathy in this
puppy
was secondary to frequent and
unnecessary vaccination.
Commentary: Although membranoproliferative
glomerulonephritis is reported as 1 of
the most
common glomerulopathies in dogs, a
definitive
diagnosis and identification of the
offending antigen
are rarely identified due to the risk
and
expense associated with renal biopsies
and electron
microscopy.
This case report
demonstrates
that injudicious use of vaccinations
may, like
other infectious or autoimmune diseases,
lead to
immune complex deposition and subsequent glomerular damage.
When possible,
appropriate
education should be provided regarding
the
rationale for current vaccine guidelines
to avoid overvaccination.
Further studies are
required at
this time to determine the role, if any,
that recent
past and current vaccine protocols play
in the
development of protein-losing
nephropathies.
Shawn Kearns, DVM, Diplomate ACVIM
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