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Cardiovascular Disorders of Cats
Heartworms in cats
Congestive heart
failure and CRF
Sudden Death in Cats
Aortic
thromboemblism
Pleural effusion
- chylous or pseudochylous
Heartworms and cats
Heart disease and hyperthyroidism
Heart failure - kidney
failure
Congestive heart failure
after anesthesia
Secondary Myocarditis
Fluid on Lungs - possible pulmonary
edema
also see - Cardiomyopathy
also see Heartworm Disease
also see Heart Murmur
Congestive
heart failure and CRF - Zack
Q: Dear Dr Richards,
Thank you for your rapid and thorough responses to my questions about
Zack,
my cat with CRF and congestive heart failure. I took him in for
a followup
exam, after 2 weeks on 1 tablet Enacard, 1/2 tablet of Lasix, and decreasing
to 50 ml saline per day. His heart sounds were normal (having
been slow
and/or hesitating, previously), as was his breathing. I was thrilled
to
hear it. However, the next day, I got his blood test results, and his
BUN had
risen from 33 to 40. We're back to where we started, before starting
subq
fluids. My vet has responded by decreasing his dose of Lasix
to 1/2 tablet
every OTHER day. It seems to me that increasing his fluids would
be better,
if flushing the kidneys is what we want. Does this seem like the right
course to you? How can we know whether Enacard is doing anything
for him, as
opposed to Norvasc which I found out belatedly you prefer? You've written
that CRF cats should be followed more closely than is usually done,
to slow
the progress of the disease, how often is ideal?
L and Zack.
A: L
I would tend to continue with daily fluid therapy with a willing owner
in
the situation you describe with Zack, in most circumstances. However
there
are times when a physical examination finding changes my opinion on
this
course of action, so it would be best to ask your vet why the change
was
made. There isn't all that much difference between a BUN of 40 and
a BUN of
33. This probably falls within the normal variation for testing. So
that
may also be a factor in your vet's thinking on this. I think it is
best to
stick with either enalapril (Enacard Rx, Vasotec Rx) or amlodipine
(Norvasc
Rx) for at least 60 days once you start, because I think it takes that
long, sometimes, to see the difference the medications are making.
After
that time, if there doesn't seem to be enough benefit from the Enacard,
it
would be worthwhile to try Norvasc, probably.
Mike Richards, DVM
9/8/99
Sudden death in cats
Q: I'd like to pose a question about our cat, Mookie,
who up and died while we
were petting him this past Sunday.
I've searched the web and all pet sites about SUDDEN DEATH and have
found
this "affliction" only in the context of heartworm. I wonder if you
have
other ideas on this? Mookie was a healthy active 11-year-old Manx.
All shots
up to date. No lethargy or appetite suppression. He was purring one
moment
and the next he let out a blood-curdling scream, then died.
Thanks in advance.
A: Lisa-
Real "sudden death" is an unusual occurrence. As you noted, it can happen
in cats infected with heartworms. It is also reported to occur in cats
as
the result of cardiomyopathy. This disorder can be very insidious and
may
not be detected prior to death. Cats probably get aneurysms that rupture,
although I have only seen one report on these. Anything that causes
thromboembolism can cause sudden death -- this can be seen as the result
of
cancers, blood clotting disorders, cardiomyopathy, trauma and other
disorders. Low serum potassium can lead to sudden death, as can high
serum
potassium -- but usually there are other signs of illness making the
process seem a lot less sudden in retrospect.
I am sorry to hear about Mookie. It is unfortunate but without a necrospy
(autopsy) exam it is not possible to tell you what might have happened.
It
is hard when things like this can't be resolved.
Mike Richards, DVM
4/12/99
Aortic thromboembolism
Q: I was pleased to find your site.
I recently lost my 2 and a half year old white socked tabby (Meshach) to saddle thrombosis. I feel terrible. I want to learn
more about the disease, not because I think my vet could have done something and didn't want to,
but because it seems like such a sticky problem. I am simply eager to learn about what the cutting
edge research is. I am partly interested because I would like to know as soon as researchers
have any ideas of how to treat
it, either preventatively or as trauma. My wife and I have four
other cats, one is Meshach's brother of the same litter. If you could point me to more information
about who might be studying treatment for this, I would be grateful.
Thank you in advance,
Ken
Also thank you for your encyclopedia entry on Cardiomyopathy.
A: Ken-
I am sorry for the long delay in responding to your email. In general
we
are only responding to subscribers to the VetInfo Digest at this time
but
we did not have much information on the site about this problem and
therefore I set your mail aside to answer and have just gotten to it.
I am not sure if there is cutting edge research going on when it comes
to
this disorder. There may be, I am just not aware of anyone currently
researching this and have not seen much information in the literature
recently. Aortic thromboembolism in cats has not been very responsive
to
medical or surgical treatment in past studies, unfortunately.
In most cats aortic thromboembolism occurs secondarily to heart disease
in
cats. Blood clots form in the damaged or inefficient heart and are
sent
into the circulation. They tend to cause blockages in the aorta in
the
lower abdominal region or the area in which the aorta splits to become
the
femoral arteries of the legs (this is where the term saddle blockage
comes
from, I think). Blood clots can form due to other circulatory disorders,
infections, hyperthyroidism and probably other problems but these are
much
less common causes than heart disease.
Treatment is usually attempted using medications that inhibit or break
up
blood clots. Heparin is most commonly used in veterinary medicine but
other
medications have been used. The survival rate of cats in the initial
bout
of aortic thromboembolism is probably about 30 to 50% with treatment
for
pain, medications for blood clotting and correction of problems that
are
associated with thromboembolism, such as hyperkalemia. Some cats would
probably live that are ultimately euthanized due to inability to recover
the use of their legs even though they are stable otherwise. These
would be
reasonably good odds if it weren't for two problems. The first is that
the
underlying disease must be treated successfully (the heart problem,
infection, etc.) in order for the cat to continue to do well. The second
problem is that a lot of cats have recurrences of the thromboembolisms
even
when treatment for the underlying condition seems to be going well.
I
haven't found a figure for the recurrence rate or for survival at one
year
later for cats that suffer from aortic thromboembolism but I am pretty
sure
that both statistics would be disheartening. Due to these problems
it is
important that clients understand that treatment for this condition
involves intensive care with attending potentially high costs and that
the
odds are still not good. If that is clearly understood and a client
wants
to pursue therapy, anyway, there are published treatments.
Catching any heart conditions early and treating for them may be the
best
way to prevent this problem. Older cats should be evaluated at least
yearly
for signs of heart disease and appropriate treatment measures taken
if
heart disease is found. I don't know of any other treatment options.
If
aspirin were a little safer to give to cats it might prove beneficial
as a
preventative therapy but I would be very hesitant to start a cat patient
of
mine on long-term aspirin therapy to interfere with blood clotting
as is
often advocated for humans.
Hope this helps.
Mike Richards, DVM
Pleural
effusion - Chylous or Pseudochylous
Q: Dear Dr. Richards:
Our cat, Suggy, had a hacking cough for several months. Our vet.
thought he
had hairballs so she gave us some hairball medicine. The hacking
cough
persisted. We took him to the Vet again, and she said that maybe
it was an
allergy. So, she gave him an antihistamine shot. The cough
disappeared,
but about two weeks after, Suggy started having trouble breathing.
We took
him to the vet. again. She found milky fluid in his lungs and recommended
that we
give him Bactril and take him for a chest X-ray. Then, she said
that
what he really needed was an ultrasound.
We took him for an ultrasound. The second vet. found more fluid
in his
lung. He thought Suggy may have a mass on his right lung. He
said that all we
could do was wait two weeks and bring him back for another ultrasound.
By this time, Suggy had stopped eating and barely drank. He was
growing
weaker everyday.
Three days after the ultrasound, he was not able to breath again.
We took
him to the first vet. (our mistake, we should have taken him to the
University of Pennsylvania Veterinary Hospital) who said that he still
had fluid in his
lungs, this time of a clear color.
Two days after the first vet. sent Suggy home, we had to rush him to
the
University of Pennsylvania Veterinary Hospital. He could barely
keep his
head up, could barely breath, and had not eaten or drank in days.
At the Penn Vet. Hospital, he was placed in an oxygen cage in the emergency
room. The emergency room doctor said that she needed to run some
diagnostic
tests to find out exactly what was causing Suggy's CHYLOUS EFFUSION.
She
said that we still had a small chance of helping him recover.
The next day, Suggy had been moved to Intensive Care. The Intensive
Care
doctor said there was nothing else she could do - if she tried to do
some
diagnostic work on Suggy that he may suffer from cardiac arrest.
She
said he was too weak for her to do anything.
We had to agree to Suggy being put to sleep on Friday, July 31, 1998.
Our question now is: don't you think our first vet. should have
clearly
stated that fluid in the lungs is CHYLOUS EFFUSION, that we needed
to ASAP
find out what was causing it to treat it?
If we had had the diagnostic work done on Suggy while he was still a
strong,
otherwise healthy, cat then maybe we could have started him on treatment
before he was too weak to hold his head up.
What do you think, Dr. Richards?
We are thinking of writing a "disappointment" letter to our first
vet., with a cc: to the Veterinary Licensing Board in Harrisburg, PA,
stating how we wish
she would have given us the full picture when Suggy first started hacking
and when she first tapped the milky fluid.
Thank you for your attention to this message.
We really appreciate your concern.
Mournfully yours,
Frances
A: Frances-
I can not tell for sure from reading your email whether the effusion
was a
chylous effusion or a pseudochylous effusion. The first is a specific
condition involving leakage of chyle into the pleural space and the
second
is effusion that looks like chyle but isn't, which can occur with other
diseases.
Due to the difficulty in explaining pleural effusions I think it is
important to start with an explanation of how the pleural lining normally
functions and then try to explain what can go wrong and what the results
are. This will make it easier to understand why your question is harder
to
answer than many that are sent to our web site.
The pleura is the lining of the chest cavity and the lungs. It is a
thin
layer of specialized cells that coats the inside of the body wall (the
parietal pleura) and then in a continuous sheet also covers the lungs
(the
visceral pleura). The pleura in cats does not segment itself completely
into a right and left side so cats usually do not have pleural effusions
on
one side only as happens in some species. Dogs also have connections
between the pleura of the right and left sides of their thorax so they
are
similar in this aspect. This is really simplistic but it might help
to
think of the pleura as a bag stuffed between and adhered to the lungs
on
one side and the body wall on the other.
The pleura normally produces fluid and the fluid is normally absorbed.
When
things are working right, there is a small amount of fluid present
to
lubricate the two sides of the pleura so they can rub smoothly over
each
other. In general, the parietal pleura produces more fluid than the
visceral pleura and this produces a flow of fluid across the pleural
space
from the body wall into the lungs as the visceral pleura absorbs the
fluid
through small capillaries and lymphatic vessels. Even though only a
small
amount of fluid is present in the pleural space at any one time a lot
of
fluid crosses the space.
Fluid accumulates in the pleura space when the production and absorption
processes get out of synch. This can happen when too much fluid is
produced
by either side of the pleura. It can happen when the pleura can't absorb
the fluid as it normally would but production of fluid remains normal.
In
some cases there are disturbances in fluid production and in fluid
absorption which can lead to pretty rapid accumulations of fluid and
severe
respiratory distress as the fluid makes it impossible for the lungs
to expand.
Heart failure, usually from cardiomyopathy in cats, is one cause of
changes
in the fluid pressures. As the heart function decreases blood accumulates
in the lungs because it isn't being pumped out of them. This raises
the
blood pressure in the pulmonary capillaries which normally drain the
fluid
from the visceral pleura. The pressure in the parietal pleura vessels
may
remain the same or lessen. This makes it impossible for the fluid to
flow
from the parietal pleura to the visceral pleura so it just accumulates
between the two sides.
If the lymphatic vessels leak or if the pressure in these vessels increases
so that they can't absorb fluid then the pressure changes for a different
reason but the effect is the same. Without the help of the lymphatic
vessels to drain fluid, there is not enough movement of fluid into
the
visceral pleura and once again, the result is accumulation of fluid
in the
pleural space. True chylothorax occurs when the lymphatic vessels are
torn
or leak for some reason. Pseudochylothorax occurs as a secondary change
after another type of effusion has occurred.
Fluid accumulation in the pleural cavity can be classified several ways.
It
can be convenient to think of the fluid as either a transudate (fluid
accumulation with very few cells in it and low protein, usually the
result
of pressure changes only), modified transudates (fluid with some cells
in
it and higher protein) and exudates (fluid with lots of cells, even
higher
protein and generally too cloudy or turbid to see through).
Low blood protein levels are the usual suspect when there is fluid that
can
really be called a transudate.
Modified transudates occur with lots of diseases, including cardiomyopathy,
heart failure for other reasons, lung damage for any reason, diaphragmatic
hernias, cancer, hyperthyroidism in cats, heartworm disease, feline
infectious peritonitis, feline leukemia virus (usually due to lymphoma),
trauma, bleeding disorders and probably other stuff.
Exudates occur for most of the reasons above if the disease process
continues long enough. The modified transudate may be present for a
long
time prior to the disease worsening or may be a very brief stage in
the
march towards an exudative process. Some disorders start out as exudates.
Chylothorax due to damage to the lymphatic vessels from trauma, cancer
or
for no apparent reason is an exudate right from the start. Pleural
abscesses
and infective material from wounds to the chest are exudates right
from the
start, too.
Whether the disorder is a transudate, a modified transudate or an exudate,
it is an effusion if abnormal amounts of fluid are accumulating in
the
pleural space.
By withdrawing some of the fluid from a pleural effusion and examining
it for
cells, protein levels, color, odor and specific gravity, it is often
possible to make a pretty good guess as to the cause of the fluid
accumulation. If the fluid contains cancer cells, if it is a true chylous
exudate or if it looks like and smells like pus examination of the
fluid
gives a strong clue as to what is going on.
It is hard to differentiate between chylous effusions and pseudochylous
effusions based on appearance alone. It is possible to get some idea
of
what the fluid is by letting it sit overnight and looking for separation
of
a "cream" layer or by mixing the fluid with ether to see if it clears.
Most
practices don't have ether around anymore, though. Submitting the fluid
for
lab evaluation is helpful because true chyle is high in triglycerides
and
low in cholesterol. Pseudochyle is lower in triglycerides and higher
in
cholesterol.
I am not sure why your vet or the vet who did the ultrasound exam did
not
attempt to identify the fluid or did not tell you what it was if they
did.
I am also not absolutely certain that the vet at the University of
Pennsylvania was certain that the fluid was a true chylous effusion
at the
time that the comment was made (if it was made just after withdrawing
the
fluid as it appears to have been in your note) -- the diagnostic tests
might have been necessary to determine whether the fluid was a chylous
effusion or a pseudochylous effusion, especially with the history of
it
being clear the last time your vet took a sample.
The problem in answering your question is this: was the fluid really
chyle?
If so, then early aggressive treatment may have helped but medical
treatment for chylous effusions is pretty difficult and works best
when the
effusion is occurring due to trauma that can heal itself. Surgical
treatment isn't highly successful but can be attempted when medical
treatment isn't working well. If the fluid was a pseudochyle, why was
it
occurring? If an underlying cause could have been identified and treated
then there may have been some hope. If the cause was cancer or severe
cardiomyopathy then a good outcome was still pretty unlikely.
If a necropsy (autopsy) was done then you may know the answer to these
questions. If so, it would be best to review it and to try to make
an
assessment of the likelihood that treatment would have been successful.
There is more likelihood that the outcome would have been the same
than that
successful long-term treatment could have been achieved but it might
help
to know that for sure. I think that it would have been best if your
vet had
realized that you wanted to treat this situation as aggressively as
possible. It is easy for general practitioners in veterinary medicine
to
assume that people do not want to pursue aggressive diagnostic processes
and aggressive therapies where the potential for a good outcome is
small.
Despite this, it is important to remember that some clients do want
to go
all out and to keep an open mind about that. It is also fair to expect
your
vet to make an attempt to explain the disease process so that you can
understand it and make decisions accordingly. It is also pretty easy
to
make statements that are more definitive than the situation warrants
when
treating emergencies or in intensive care situations. It seems possible
that this happened, too. For this reason, it is equally important for
there
to be follow-up and an explanation of whatever lab tests were done
when a
patient dies.
It is too late to change the situation now, but your email reinforces
the
need for veterinary clients to to remember that there are specialists
in
veterinary medicine and that asking for referral to one when any treatment
or diagnostic process doesn't seem to be working well is a reasonable
thing
to do. It is not necessary to wait for your vet to suggest this.
I am sorry to hear of your loss. I hope that this explanation isn't
burdensome. It would be best to contact your vet, either by letter
or in
person, to discuss all of this and to help to resolve whether more
could
have been done. If there was never a definitive diagnosis, either through
the labwork done at the University of Pennsylvania or through an autopsy
exam, it may be impossible to ever know for sure whether the outcome
could
have been changed. That would be true even in most cases in which true
chylothorax was present or a disease process severe enough to cause
a
pseudochylous effusion was present due to the difficulty in treating
many
of the underlying disease processes. It is very very difficult to live
with
uncertainty in the death of a pet and I know that is making this whole
thing harder for you. I hope that you do find some resolution through
discussing this with your vet or the vets at the University of Pennsylvania.
Mike Richards, DVM
Heartworms and cats
Q: Dear Dr. Richards,
I have spoken with cardiologists at various teaching universities who
surgically remove heartworms from cats. Dr. Gavaghan (U.C.-Davis),
Dr.
Rawlings (U. of Georgia), and Dr. Eyster (Michigan State Univ.) remove
the
worms through the jugular vein. Dr. Bill Brown (Michigan Veterinary
Specialists) uses a different approach which is thoractomy and incision
into
the right atrium to lift them out. All combined the number of surgeries
using both methods totals approximately 16, so there's not a lot of
experience doing this although they seem to be successful, based on
what
they've told me.
The purpose for my note is to ask your advice regarding how to decide
which
avenue is best for the cat's survival based on the procedures described
above or to continue treating the symptoms with Prednisone and
Aminophylline. How would you recommend that a person base this decision
(removing cost as a factor)?
In my cat's case, she was diagnosed in May '98. Her symptoms became
very
serious for several days in early July - vomiting, diarrhea and gasping.
My
vet injected her with Prednisone and added Aminophylline and Furosemide
to
the menu. Of course, we don't know what happened, whether a worm died
or
not, but she suddenly stabilized and has been 100% without symptoms
for the
past 6 weeks.
A second question that I have for you is what your thoughts are regarding
the fact that she has no symptoms now and that I'd like to reduce the
amount
of medications she is taking. We recently decided, since her
lungs sound
clear now, to drop the Furosemide to once a week. I am also considering
dropping the frequency of Aminophylline (currently 25mg twice/day)
to once a
day, and perhaps removing it entirely if she continues to be free of
symptoms. The reason for this is that I travel for business and, considering
my responsibility for giving her all these meds each day, have been
unable
to leave her. She was once a feral cat who has become very attached
to me.
No one else can get near her. It's a bit of a dilemma especially considering
the long duration of this disease. That is another reason why I am
gathering
information on a surgical approach, it would bring this disease to
an end,
hopefully successfully.
Thank-you for your time.
Nancy
A: Nancy-
It might be a good idea to consider retesting for heartworms. It would
not
be unusual for a cat to have a single heartworm and the symptoms you
have
seen would be consistent with death of a heartworm. We have seen the
antigen disappear from the bloodstream in as little as two months in
one
cat. If there was a positive antigen test previously and it becomes
negative that would be a good sign. Ultrasonagraphy is another method
of
assessing whether or not worms are still present. University practices
may
offer even more sophisticated testing such as nuclear scintigraphy
using
radiolabelled antibodies against heartworms.
If heartworms are still present it would be necessary to continue to
consider which form of therapy to go with. While I don't have any personal
experience with heartworm extraction in cats to go on I do think that
I
would consider it as an option. Both the presence and eventually the
death
of the heartworm are dangerous for the cat and eliminating the worms
surgically would reduce that risk immediately if successful. Since
some
sort of imaging to identify the location and number of worms would
be a
good idea prior to surgery the testing mentioned above would probably
be
part of the work-up for the procedure.
When clinical symptoms diminish we taper off the medications. So far,
this
has worked well for us when the cat has been symptom free for 6 weeks
or
more prior to withdrawal of the medications but the number of cases
we have
treated in this manner is still only about 3 cats. We chose 6 weeks
arbitrarily.
If possible I'd base these treatment options on confirming that heartworm
disease is still present. If that is not possible and symptoms have
lessened I think it is reasonable to taper off the medications and
see what
happens. If that is not possible and symptoms remain then I think the
choice is harder. Since there are few cases to base a decision on you
may
just need to make a choice arbitrarily. Trust your instincts if it
comes to
this.
Mike Richards, DVM
Heart
disease and hyperthyroidism
Q: Dear Dr. Mike, My cat Linus is 13 years old
and was diagnosed yesterday with a heart murmur. Our vet did a blood panel
and discovered a slight elevation in his thyroid levels with low K and
phos. levels. With this info I will be starting him on Tapazole 1/2 tab
dailyin addition to K supplement. My concern lies in his dental care since
I normally have his teeth cleaned annually. I am very afraid with this
condition to expose him to anesthesia. However he does have bad tartar
build up which makes yearly cleanings necessary. I would appreciate your
advice in this matter. Do we jepordize his teeth or just take the chance
that the anesthesia will not be rough on him. Thanks Linus and Cathy
A: Linus and Cathy- Heart murmurs can occur with hyperthyroidism and
may disappear with treatment. If your cat can be stabilized and the clinical
signs improve it should be reasonably safe to use anesthesia. Choosing
an anesthetic with minimal cardiac effects (we use isoflurane gas) is helpful.
While there is undoubtedly increased risk of anesthesia when a cat may
have cardiomyopathy associated with hyperthyroidism we have not had an
anesthetic death yet while anesthetizing cats we know have hyperthyroidism.
I would work at stabilizing the problem with hyperthyroidism before considering
routine care if at all possible but if this can be done it should be OK
to consider the teeth cleaning.
Mike Richards, DVM
Part 2 - the good news
Dear Dr. Richards, I just wanted to take a few minutes to thank you
for your reply. Due to the information in your e-mail and the information
contained in your web page ( Cardiomyopathy )I talked to my vet about doing
an echocardiogram on Linus to check for any heart disease. Well the test
are in and due to early detection of his hyperthyroidism their was only
a slight thickening of the cardiac muscle. With treatment he should be
well on his way to a good 5 more years maybe more. This just proves that
yearly visits to the vet are critical in detecting these treatable conditions
that can cause so much damage. Thanks again your web page is wonderful.
Cathy and Linus.
Mike Richards, DVM
Heart failure
- kidney failure
Q: Dear Dr. Mike, My cat was euthanized one day
ago. My cat Sam (15 yrs) had been diagnosed in January with kidney disease.
After he was in doctors care for 1 week, we took him home to care for him.
His bun was brought down from the 120 range to the mid 40 range. His creatnine
levels were reduced from mid 7 to normal range. However, by March, these
levels were up again. Bun was 90's. Reading on the web about sub-q fluids,
I started administering to him 100cc daily. A further check up one month
later, still showed a high bun of 120. I proceeded to double the dosage
and was giving 200 cc daily, 100cc morning and 100cc night. He seemed to
be in fairly good spirits, up until a week ago, when we noticed he was
not eating or drinking. Then two days ago he was breathing harder. We took
him to an emergency clinic (Memorial Day) and was told he was suffering
from respiratory failure. They put him in an oxygen tent overnight and
were giving him diuretics to remove the fluid that was found by x-ray to
be around the lung cavity as well as inside the lung. They hoped that thru
the night he would urinate, which he did, and that he would breathe without
the need for oxygen. Unfortunately, he was not able to leave the oxygen
tent without gasping for air. At that point the following morning, we made
the decision to end his suffering.
My question to you, since we did not have our regular vet available
due to the holidays, is the congested heart failure, usually an end result
to renal failure? I had been ,up until a month ago, giving him epogen shots,
because he had anemia. Once that was under control, the vet said I did
not need to give them to Sam, until the next visit, which we were coming
up against almost one month later. Could the lack of epogen have caused
his sudden heart problems? The vet said his heart was enlarged at the time
we brought him into the emergency clinic. I am wondering if this could
have been prevented, in any way. I know he was old, but if I could have
prolonged his life without suffering I would have done it.I am very saddened
by my loss. Thank you for your help and advice in this matter. Faye
A: Faye- It sounds like you and your vet were making
the best possible effort to care for Sam. Epogen (Rx) is used to treat
the anemia associated with chronic kidney failure. Discontinuing use of
it should not have caused cardiomyopathy, to the best of my knowledge.
The most common cause of cardiomyopathy in older cats is probably hyperthyroidism.
Unless there were clinical signs of this, it seems unlikely that it would
have been advanced to the stage where it would affect his heart, though.
Heart enlargement is not always due to cardiomyopathy in cats. Sometimes
heart failure occurs for other reasons and still results in an increase
in the size of the heart. It really does sound to me like you and your
vet were providing Sam with good medical care. Please don't make yourself
feel guilty unnecessarily. Sometimes, the best we can do is not good enough.
Mike Richards, DVM
Congestive
heart failure after
Q: Dear Dr. Mike, I brought my eleven year old
cat to my veterinarian today for a dental prophylaxis. A few hours later,
I received a call that she had experienced congestive heart failure immediately
after she was administered anaesthesia. She was placed in an oxygen tank
for several hours. When I visited her, she was breathing quite deeply.
Tomorrow she is scheduled to undergo Ultrasound, an EKG, as well as have
blood work completed. I am extremely distressed and cannot dismiss the
notion that she had an adverse reaction to the anaesthesia. She had a normal
heartbeat during her annual examination one month ago, as well as immediately
prior to her treatment today. She has never had labored breathing or any
of the other symptoms associated with congestive heart failure. I would
truly appreciate any advice or suggestions regarding this matter. Thank
you. Sincerely, J.
A: I would be suspicious if I was in your position,
too. We have discovered cardiomyopathy in a cat in our practice with anesthesia
in much the same manner, though. This is an insidious problem and can be
hard to detect prior to the onset of symptoms or prior to a stress such
as anesthesia. The testing should help clarify this situation. It is always
hard to accept when "routine" things turn out to be not so routine. I hope
all turns out well.
Mike Richards, DVM
Congestive heart failure after anesthesia - Part 2
Q: Dear Dr. Mike, Thank you so much for addressing
my concerns regarding Tasha. Although Tasha's EKG was normal, the ultrasound
indicated that she was suffering from cardiomyopathy. My DVM still has
a number of questions for the Dr. who evaluated the ultrasound and will
contact me when he receives a more definitive answer. We brought Tasha
home on Thursday and she appears to be getting stronger each day. She just
began eating on her own today and is taking a quarter tablet of Atenolol
daily. I often wonder, had Tasha not been anesthesized, would she have
lived to age fifteen without ever having exhibited signs of heart failure.
I was always extremely fearful of anesthesia and now I am very distressed
that I may have significantly shortened Tasha's life by allowing her to
be anesthesized. I would truly appreciate any thoughts which you may have
regarding my concerns. Sincerely, J.
A: I am not sure if the episode you had will have
any long lasting effect. The cardiologist may be able to answer that more
definitively. So far, we have had pretty good luck treating cats with this
problem when we have been able to identify it. I guess I'd hope that finding
it now may save some damage that would have occurred while it continued
to develop.
It is good to have a healthy respect for anesthesia. You always have
to weigh that against the benefit of what you are trying to do. I really
think that most animals live longer if things like dental disease are taken
care of, even with the anesthetic risk factored in. It is just not entirely
safe and some pets come out on the losing end of the risk/benefit ratio.
It never seems consoling enough to say that the odds were in a pet's favor
when things have gone badly. There just isn't much to say when good decisions
have bad outcomes.
I hope that Tasha continues to improve on the medications and that she
does keep going for a number of years.
Mike Richards, DVM
Secondary
Myocarditis and Diabetes
Q: I am trying to find information about congestive
heart failure in cats. My cat is diabetic and has had a bout of kidney
disease. He is currently taking insulin and is on diet therapy. I was told
that congestive heart failure is a possibility. I am interested in knowing
what symptoms I should look out for and what the possible treatment is.
Thanks.
A: Diabetes mellitus can lead to a secondary myocarditis
(malfunction of the heart muscles). This can eventually cause heart failure.
The signs that this is happening include a decrease in activity or weakness
associated with normal activities, difficulty breathing or increased respiratory
rate, decrease in appetite and sometimes pain or paralysis of the rear
legs. Unfortunately, most of these signs can also occur for other reasons,
including other complications of diabetes, like diabetic neuropathy leading
to hind limb weakness or decrease in appetite associated with a loss of
control of insulin regulation. With diabetes, it is important to work very
closely with your vet to monitor the treatment. Teamwork makes a huge difference
in the successful maintenance of a dog or cat with diabetes.
I hope that you never have to worry about this complication of diabetes.
Mike Richards, DVM
Fluid in lungs - possible
Pulmonary
edema
Q: Dr. Mike, For the past two weeks I have been
desparately trying to find out what is wrong with my cat Miles.
For the last month, Miles (age 6) has been laying around a lot, but sometimes
he does that. Then on 2/26/97, I came home from school and
he acted, funny he meowed a lot did not eat, when he went out to potty,
he stumbled down the steps, he was also breathing fast. It looked
like his rear end was pretty shaky. I took him to the vet, they tested
for leukemia and FIV, both negative, they tried to get more blood to do
more tests and Miles got really stressed. They gave him some injections
of steriods and antibiotics and sent him home with amoxicillian.
His balance came back, but he hasn't been eating much, unhappy with the
service from my regular vets office, we took Miles to a new vet for his
continued rapid breathing. He took X-Rays, the vet said from the
x-rays he could not see a diaphragm, because of fluid build up, Miles has
been getting shots (anti-inflam., antibiotic, diruetic) almost daily from
the new vet to reduce the fluid in order to get a better xray. The
vet said it could be a torn diaphragm or any number of other things.
Tomorrow they are supposed to re x-ray him. For the past two
days Miles has had shots to increase his appetite, they have worked
so-so. Miles' breathing is much improved, but I don't know what to
prepare myself for. I feel like this is my child and want to know
what to do as quickly as possible. Any ideas, comments, or suggestions
that you may have would be greatly appreciated!
A: I am not going to be able to help you decide
which of the following conditions I list is actually affecting your cat,
Miles. There isn't enough information in your letter to tell if this is
pulmonary edema (fluid in the lungs) or a pleural effusion (fluid around
the lungs). Based solely on probability I would guess that this is a pleural
effusion because they are a lot more common - but it is a guess.
Pulmonary edema is seen with heart failure, conditions causing low blood
protein levels, cancer, pneumonia, "shock lung" or acute respiratory distress
syndrome and some other less likely problems. Identifying the cause helps
a lot. It is hard to do when there is a lot of fluid present in the lungs,
so it is sometimes necessary to treat symptomatically for a while in order
to be able to get reasonable X-rays.
Pleural effusion is more common in cats. The most common cause of pleural
effusion is cardiomyopathy (weakness of the heart muscles). Other causes
include abscesses in the pleural space (pyothorax), chylothorax (leakage
of chyle from the lymph ducts into the pleural space), other causes of
heart failure, cancer (feline leukemia causes cancer), diaphragmatic hernias,
lung lobe torsion and lots of other less common things cause fluid in the
pleural space. We like to draw the fluid off the chest if we think it is
pleural fluid. It took me a long time in practice to get comfortable doing
this, though. I'm not sure why it took me so long to quit worrying about
damaging the lungs and just do this, because it seems to help a lot in
many cases. Another advantage of doing this is that you get to look at
the fluid and analyze it. That can be really helpful in deciding how to
treat the problem. It is not possible to draw off fluid dispersed throughout
the lungs so this won't work with pulmonary edema. Many vets prefer to
treat aggressively with diuretics to get rid of fluid in that manner. We
have to do that even after drawing fluid off in most cases.
Just based on your cat's age, feline leukemia and FIV negative status
and the clinical signs you describe, this is likely to be cardiomyopathy.
X-rays after the fluid is controlled will help with a diagnosis but this
condition is best diagnosed with ultrasound exam, so you may be facing
more than one round of testing at this point. It is important to do this,
even though it is frustrating to keep having to go back over and over again
to reach a final diagnosis. As you can tell from the lists of possible
problems above, there is also a really strong possibility that this is
something else, entirely. Hope this information doesn't just make it all
the more confusing for you.
Mike Richards, DVM
Continued:
Q: Dr. Mike, Thanks for your information on Miles'
probable condition Today's xray still showed too much fluid. The vet gave
us the following options: him do surgery to try and find out what is going
on, or take Miles to the local university for an ultrasound. The vet said
given Miles' stress level that he should be considered extremely high risk
for surgery. The vet also said that getting the ultrasound would probably
cost $600. I don't know what to do. The vet said cardiomyopathy is a possibility
as is a torn diaphragm. If it is cadiomyopathy that is it treatable? For
easily stressed animals, should surgery be a last resort? Miles has not
eaten since yesterday and he looks like he is on his last leg. Any help
that you can offer is greatly appreciated. Thanks in advance.
A: I can't tell for sure from your note, but if
the local university has a veterinary school, I would definitely go and
at least get a second opinion. If this is cardiomyopathy it will be necessary
at some point to have an ultrasound exam done. I am not sure what they
cost in your area, but the ultrasound exam itself tends to be around $150
in our area. Of course, the total bill may be significantly more than just
the cost of the ultrasound exam alone. One advantage of the school is that
they will also have a clinical pathologist who can examine the fluid and
it is very likely that they will be able to give you a pretty good idea
of the prognosis before doing an ultrasound exam, based on an analysis
of the fluid.
I really think it would be worthwhile to go, if there is a veterinary
school near you.
Michael Richards, DVM