Hypertension is usually known as high blood pressure.  It is a common condition in older cats and can cause serious health problems including blindness and stroke.

What causes hypertension?

Fat tabby cat drinking water outsideIn most cases (about 80%) hypertension is caused by another health problem.  These include:

  • Kidney disease
  • Hyperthyroidism (overactive thyroid gland)
  • Adrenal tumour (rare)
  • Anaemia (rare)

In about 20% of cases, hypertension seems to have no underlying cause.

Why is hypertension a problem?

High blood pressure can cause small blood vessels (capillaries) to burst.  Depending on where these bleeds occur, problems can develop.  These bleeds can happen very suddenly without warning.

If the bleeds occur in the brain, the cat will have a stroke.

If the bleeds occur in the back of the eye, the cat may become blind.

High blood pressure can also lead to kidney disease, or make existing kidney disease worse.  It can also cause heart problems.

How is hypertension diagnosed?

Blood pressure machineRegular blood pressure monitoring is advised in all older cats (over 7 years), at least annually.  Blood pressure is measured in a very similar way to people, with a cuff around the front leg or tail.  It is not painful but can feel a bit strange.

Some cats have ‘white-coat syndrome’, which means their blood pressure is high due to stress.  In these cats, allowing them to calm down or giving a light sedative or anti-stress medication can help to get an accurate reading.  If a cat’s blood pressure is high, but they are otherwise well, it is worth checking that the high blood pressure is repeated on a few occasions before starting on any treatment

Looking at the back of the eye can show small bleeds which may have occurred due to high blood pressure.  If these are present, along with a high blood pressure reading, treatment is needed.

If your cat has high blood pressure, further investigation will be needed to assess the underlying reason.  This will usually involve a blood test and urine sample in the first instance.

How is hypertension treated?

There is a very effective medication to treat high blood pressure called amlodipine.  It comes in a tasty tablet especially formulated for cats and is usually accepted very well.  It is usually given once a day.

If this medication is not sufficient on its own, there are other treatments that can be added in.  If the blood pressure is only slightly high, some of these treatments may be used instead of amlodipine.

Related pages

Chronic kidney disease