What is
high blood pressure?
High blood
pressure (hypertension) is something that most people associate
with humans. It is also described as 'the silent killer' as
often high blood pressure may be present for a long time without
any symptoms, and the problem may only be
discovered when a doctor (or veterinarian) checks the blood
pressure.
The heart pumps
blood around the body via the arteries. Blood pressure is the
force in which the pumping blood is exerted against the walls of
these arteries. Think of your arteries as a pipe, in high blood
pressure, the blood is pumped through these 'pipes' at a higher
pressure than normal.
Most of us have
had our blood pressure routinely taken by a doctor, and will be
aware that there are two readings. The first number (the highest
one) is known as systolic pressure, and is the pressure in the
arteries as the heart contracts & sends the blood into the circulation.
The second number (the lower one) is known as diastolic pressure
& occurs as the heart relaxes & fills with blood.
Primary
hypertension (essential hypertension) is extremely rare in cats.
Most hypertensive cats have secondary hypertension, which is a
result of an underlying disease. Common causes of high blood
pressure in cats are hyperthyroidism,
Cushing's
disease & kidney disease.
What are the
effects of high blood pressure?
Eyes: Swelling & bleeding into the eyes can result in
blindness. Detachment of the retina can also occur & cause
blindness.
Kidneys: The kidneys act as filters to rid the body of
wastes. Over time, high blood pressure can narrow and thicken
the blood vessels of the kidneys. The kidneys filter less fluid,
and waste builds up in the blood. The kidneys may fail
altogether.
Arteries: Over time, the arteries may harden, this, in
turn, causes the heart and kidneys to work harder.
Brain: High pressure can cause a break in a weakened
blood vessel, which then bleeds in the brain. This can cause a
seizures, stroke or coma. If a blood clot blocks one of the narrowed arteries, it
can also cause a stroke.
Heart: The
heart has to pump harder & over time this can cause the
heart muscle to become enlarged & thickening of the left
ventricle, and increase the risks of developing congestive heart
failure.
What are the
symptoms of high blood pressure in cats?
As stated above,
often there are no signs your cat has hight blood pressure. If
your cat is suffering from an underlying condition such as
hyperthyroidism for example, regular blood pressure monitoring
should be performed.
Visual impairment
or blindness are usually the first sign of high blood
pressure. The pupils are often dilated & fixed.
Other symptoms may
include, lethargy, depression &
seizures.
Symptoms relating
to underlying disease such as hyperthyroidism & kidney
disease.
How to test for
high blood pressure in cats?
High blood pressure should be suspected in any cat who has a
pre-disposing condition such as kidney disease or
hyperthyroidism.
As
is used on humans, in cats an inflatable cuff is placed on the
cat's front leg or tail. In humans, a stethoscope is also used,
this isn't possible in cats & a Doppler or oscillometric
device is used instead.
Your
veterinarian will also do a complete physical exam to determine
how much damage has been done to the organs as a result of this
condition. This will involve examining the eyes, the heart,
neurological system & the kidneys.
How is high
blood pressure in cats treated?
-
Identifying &
controlling the underlying disease which is causing high
blood pressure such as hyperthyroidism or kidney disease.
-
Medication which
helps reduce blood pressure,
these are usually calcium channel blockers, beta blockers,
ACE inhibitors & diuretics. The calcium channel
blocker amlodipine is most often prescribed.
Medications won't cure high blood pressure, but will assist
in controlling it.
-
Your veterinarian
may also recommend a low sodium diet.
-
Your cat will have
to have it's blood pressure regularly monitored by a
veterinarian.
Prognosis:
If the underlying
condition which has caused the high blood pressure can be
identified & brought under control some of the damage caused
may be reversed. It is possible to cure hyperthyroidism, however
kidney disease is progressive & cannot be cured. However, it
can be managed.
Close monitoring
is vital, and even when the blood pressure has been stabilised
it should be regularly checked. If you notice any changes in
your cat seek medical assistance immediately.
Please
note:
The
medical articles on this site have not been written by a
veterinarian & should not be considered a replacement for a
veterinarian visit. The articles are provided for informative
purposes only.
Always
seek immediate veterinary advice for any problems (health or
behavioral) in your pets.
While
great care has been made in the creation of these articles, we
cannot guarantee the accuracy or omissions on these pages. If in
any doubt whatsoever, seek professional medical advice.
