My cat has high blood pressure? You have to be kidding!
(Feline Hypertension)

No, we are not kidding. Many cats are living longer these days due to the availability of better health care specifically aimed at our feline companions. However, their increased longevity is also allowing them to acquire diseases that were not seen as commonly in the past and that we have traditionally related to geriatric humans. Hypertension (high blood pressure) is one of these diseases.

We have only recently begun measuring blood pressures in cats, thus we are at the beginning stages of understanding if an elevated blood pressure is the result of a disease, a cause of a disease, or has no bearing on a disease. High blood pressure may be primary, where the cause is unknown or possibly genetic or it may be secondary to another disease process.

Abnormally high blood pressure causes blood vessel damage, particularly in the eye, kidney, heart and brain. These damaged blood vessels will bleed, cause clots, fluid buildup, and tissue death. The mechanism for this is complex. Hypertension also places excessive strain on the cardiac (heart) muscle. The heart has to pump against more pressure (vascular resistance), causing further deterioration and as it progresses the heart enlarges and a murmur may sometimes be heard with the stethoscope.

There is no specific set of symptoms of high blood pressure. That is why it is sometimes called “the silent killer” in people. An increase in blood pressure will affect many organs, particularly the liver, eyes, kidneys and heart. Hypertension may hasten the progress of disease in these organs and may substantially predispose your cat to detached retinas and subsequent blindness.

What you might note in your cat however are the disease symptoms that hypertension itself causes. These symptoms may include a sudden onset of blindness, with one or both pupils showing abnormal dilation. Your kitty may begin ‘missing’ jumps on to chairs or the bed. Perhaps you notice your cat is bumping into things or moving very tentatively through the house. Some cats will appear to be disoriented and fail to respond to the sound of your voice, as he or she normally would do. Prior to the onset of blindness an owner might notice other symptoms. These might include weight loss, excess drinking and urinating, vomiting, change in appetite (up or down) and fast heart rate.

Feline hypertension is often to secondary to Feline Hyperthyroidism and/or Chronic Renal Insufficiency (kidney disease.) Any cat that has been diagnosed with one or both of these diseases should be monitored for hypertension every 3-6 months. Blood pressure may also be monitored routinely during any anesthetic process to be sure there is adequate perfusion of blood to tissues, especially the brain, heart and kidneys. Thus an important tool in the diagnosis of hypertension is a blood pressure monitor designed specifically for small pets.

Hypertension may be controlled with appropriate medications prescribed by your Veterinarian. A diagnosis of ‘high blood pressure’ should never be ignored or treated lightly. A routine blood pressure check indicating Hypertension may be the first clue that there is underlying disease that needs immediate attention.