HYPERTENSION IN CATS

Hypertension is the medical term for high blood pressure – a common condition in senior cats. Feline hypertension is often seen as a complication of other underlying medical conditions (known as ‘secondary hypertension’) such as chronic kidney disease and hyperthyroidism. Occasionally, hypertension occurs without any other disease being diagnosed.

Hypertension is damaging to your cat’s body. The most serious effects can be seen in the: 

Eyes – bleeding into the eyes and changes to the retina may damage your cat’s sight and even cause blindness 

Brain and nervous system – bleeding can cause neurological (nervous system) signs such as unusual behaviour, a wobbly or drunken gait, seizures (fits), dementia and coma 

Heart – over time, the heart muscle becomes thickened in cats with hypertension, and in severe cases, it can lead to heart disease. Breathlessness and lethargy/tiredness can also be seen in affected cats 

Kidneys – high blood pressure damages the kidneys and may increase the risk of kidney disease developing. In cats with kidney disease, hypertension is likely to worsen the disease over time

As hypertension is often seen as an effect of other diseases, cats with hypertension may be showing signs related to their underlying problem. For example, in hyperthyroid cats with high blood pressure, weight loss (despite eating more than usual) and hyperactivity may be the main signs of illness.

In most cats, there are no signs of hypertension until the condition is advanced, causing eye problems that can lead to sudden blindness. Making an early diagnosis can help to minimise or prevent the damaging effects of high blood pressure on the eyes and other organs.  

Where signs of hypertension are present, they can include: 

Depression 

Lethargy/tiredness 

Becoming withdrawn 

Bumping into objects 

Changes inside the eye, e.g. bleeding 

Blindness

The most common cause of secondary hypertension in cats is chronic kidney disease. It can also be seen secondary to other diseases, such as hyperthyroidism (overactive thyroid gland) in cats.

How your vet will diagnose hypertension
Measuring blood pressure only takes a few minutes using an inflatable cuff placed around one of your cat’s legs or tail. It is completely pain-free and is well tolerated by most cats. Your vet will also examine your cat’s eyes and is likely to take a blood sample to test for underlying disease.  

How is hypertension in cats treated? 
Hypertension is treated using drugs to lower your cat’s blood pressure. If your cat has an underlying disease (e.g. hyperthyroidism), this will also need to be treated, and doing so may resolve the high blood pressure. 

Ongoing Care
Your cat’s response to treatment will need to be monitored regularly. This will include repeat blood pressure measurements, along with blood and urine tests, if another disease is suspected.

What’s the outlook for cats with hypertension? 
In cats with primary hypertension (where there’s no underlying disease that has caused high blood pressure), it’s usually possible to manage the condition and prevent future complications such as damage to the eyes. 

In cats with secondary hypertension, the long-term outlook depends on how severe the disease that caused the high blood pressure is.