Cats don’t smoke, don’t consume excessive amounts of salt, and generally have stress free lives; so why do we need to worry about their blood pressure?  For a long time, most veterinarians didn’t know that feline high blood pressure, or hypertension, existed because they didn’t think about it and didn’t know how to check for it.   Subtle signs of high blood pressure in cats are increased vocalization throughout the day and more “spacey” behavior.

We now know that based on routine screening, high blood pressure is a somewhat common finding in senior cats, and fortunately a very treatable condition.  Getting good blood pressure measurements in cats is tricky because very few cats are totally calm and relaxed when they visit the vet.  There are several types of instruments that are used to measure blood pressure, and they all utilize a cuff and a mechanism for detecting when blood is able to flow through a partially occluded blood vessel.  3-5 readings are needed to make an accurate assessment of the systolic blood pressure.  A systolic reading above 180 is considered to be a risk for organ damage and problems.

High blood pressure causes heart problems and problems with circulation throughout the body.  In cats, one of the main sites affected by high blood pressure is the eye.  The tiny blood vessels in the eye can burst when too much pressure is exerted on them.  When this happens, retinal detachment, hemorrhage, and blindness can occur.  If an owner is able to detect sudden blindness in their cat and high blood pressure is diagnosed, immediate treatment can lead to regaining vision.  If high blood pressure is not treated for several days, the chances that the retina will heal and vision restored are poor.

In humans, most hypertension develops without a specific underlying health problem.  In cats, most high blood pressure is secondary to either chronic kidney disease or hyperthyroidism (overactive thyroid).  If you have a cat with either of these conditions, his blood pressure should be checked at least once if not twice a year.  When hypertension is diagnosed, blood tests to look for potential causes should be performed.

The initial treatment for high blood pressure in cats is with a medication called amlodipine.  It comes as a tablet for humans, and it isn’t that easy to cut, so many veterinarians have it compounded into a smaller dose and made into a flavored liquid.  Amlodipine is a calcium channel blocker.  Cats are typically treated orally once or twice a day.  If amlodipine and regulation of underlying conditions does not control blood pressure, other medications are added in.

Diet has not been shown to have a significant impact on feline blood pressure, but senior diets or diets designed for cats with kidney disease tend to have lower sodium and are recommended.  Blood pressure generally stabilizes within 1-2 weeks of treatment, and cats almost always need treatment for the remainder of their lives.  The exception might be a cat whose high blood pressure resolves when his hyperthyroidism is controlled.

It’s good for owners to be aware that cats develop hypertension.  Checking blood pressure should be part of a routine visit for senior cats and for younger cats with suspicious clinical signs.

Written by Dr. Wexler-Mitchell of The Cat Care Clinic in Orange, CA
Copyright © 2011 The Cat Care Clinic