The Silent Killer: High Blood Pressure in Cats
Millions of people in the United States have high blood pressure – hypertension – and many of them don’t even know it. Often described as “the silent killer” because it can be present for a long time without symptoms, hypertension is also seen in cats. It’s especially common and dangerous in older cats, whose owners usually don’t know they’re affected. Cat insurance can make it easier to ensure your cat is seen regularly by a veterinarian.
Common Causes and Symptoms
High blood pressure in cats is usually discovered as a complication of other underlying medical conditions and is therefore referred to as “secondary hypertension”. The most common causes are chronic kidney disease and hyperthyroidism. High blood pressure in cats without any underlying disease is rare and not well understood.
Hypertension is damaging to many different body systems. It can cause:
– Bleeding into the eyes
– Retinal changes such as swelling and retinal detachment, which may result in permanent blindness
– Bleeding in the brain and nervous system, causing odd behavior, a wobbly or drunken gait, seizures, dementia and coma
Damage to the Heart and Kidneys
Over time, the muscle of one of the heart chambers becomes thickened because the heart has to work harder to pump blood. In severe cases, this can lead to congestive heart failure. Affected cats may show signs of difficulty breathing and lethargy. High blood pressure also damages the kidneys and may increase the risk of kidney failure developing. In cats with existing chronic kidney disease, hypertension is likely to make the disease significantly worse over time.
Because hypertension is often seen as an effect of other disease, cats with high blood pressure may show signs attributable to their underlying problem. In many patients, though, no signs will be seen until there is spontaneous bleeding into the eye or retinal detachment. Sadly, in my experience, hypertensive cats often aren’t seen by a veterinarian until they suddenly become blind due to the detached retinas.
How to Check a Cat’s Blood Pressure
Blood pressure checking equipment for cats is similar to that used for humans, with an inflatable cuff placed around one of the legs or the tail. A minimum of 3 to 5 readings should be taken and averaged, and the cat’s demeanor must always be taken into account as it can affect the blood pressure readings. Blood pressure measurement should be performed as a part of a routine care screening for all senior cats as well as those with associated conditions such as chronic kidney disease, hyperthyroidism and heart disease.
Solving the Problem
When time allows, it’s better to treat the primary disease first, because often this will solve the hypertension on its own. In cases of retinal detachment and blindness, however, the hypertension needs to be treated first. The calcium channel blocker amlodipine is most effective, and if blindness is caught within 2 – 3 days, the retinas may reattach and vision may be restored.
Focus on Prevention
Routine wellness checks, especially for senior cats, are key in preventing serious, permanent damage caused by high blood pressure in cats. If your cat hasn’t had a routine visit in the past 12 months, schedule one today!