Hypertension in cats is usually a secondary problem. Chronic renal failure is generally
regarded as the most common cause of hypertension, with studies reporting
anywhere from 20 to 61 percent of all cats with renal failure also suffering
from hypertension. The second most common cause is hyperthyroidism. About 87
percent of all cats with hyperthyroidism also have hypertension.
The normal blood pressure for a cat is about 124 mm Hg. Older cats normally
tend to run higher than this. Any cat with a reading over 150 should be checked
carefully. (Since cats have such small arteries, most techniques simply involve
taking a systolic reading. The 124 compares to the first number generally seen
in blood pressure reports for humans.)
The following information isn’t intended to replace regular
visits to your veterinarian. If you think your cat may have feline infectious
peritonitis, please see your veterinarian immediately. And remember, please do
not give any medication to your pet without talking to your veterinarian
Cats with hypertension may have damage to the eyes, kidneys, heart, and
nervous system because these organs are not receiving the appropriate blood
flow. Some cats will initially be diagnosed after retinal damage is found on an
exam or a cat suddenly goes blind. Enlargement of the heart, with corresponding
murmurs, may be noted.
Kidney failure and hypertension aggravate one another in a vicious cycle,
leading to a faster progression of kidney failure. Neurological signs, such as
ataxia or even seizures, may be secondary to
Hypertension is diagnosed by using a small blood pressure cuff on either the
forelimb or the base of the tail. An ultrasound probe may be used as an adjunct
to detecting the pulse.
Treatment: Treatment involves the use of ACE inhibitors, such as enalapril
and amlodipine, a calcium channel blocker-both medications are used in humans.
Cats with acutely high blood pressure may need a single treatment with sodium
nitroprusside, which rapidly lowers blood pressure. This must be closely
monitored or the pressure can drop too low and leave the brain without adequate
blood flow. Cats with hypertension should have regular rechecks to evaluate the
success of their medications. Once hypertension is controlled, it is possible
that some damage to the vision may correct itself.
WebMD Veterinary Reference from "Cat Owner's Home Veterinary Handbook"