High blood pressure is well known in humans, but few owners know that cats can also suffer from hypertension. It is most commonly found in older animals with kidney failure or hyperthyroidism. It is important to monitor cats' blood pressure because hypertension can cause serious damage such as sudden loss of vision.
What is hypertension?
Blood pressure varies over time between two values: systolic blood pressure (maximum blood pressure) and diastolic blood pressure (maximum blood pressure).
Hypertension occurs when the systolic blood pressure is persistently higher than 140 mmHg.
High blood pressure can be :
- primary or idiopathic: no underlying disease is identified.
- secondary to diseases most frequently (in 80 to 90% of cases). The two main causes are renal failure and hyperthyroidism. But other conditions can lead to high blood pressure: cardiac, endocrine diseases...
- due to the "white coat effect": increase in blood pressure during the consultation with the veterinarian linked to stress.
Because high blood pressure is often secondary to disease, the finding of high blood pressure can lead the veterinarian to an underlying condition such as renal failure.
How to measure blood pressure?
Blood pressure can be measured by the veterinarian with a measuring device. A cuff is placed on the animal's leg. No anesthesia is required and the blood pressure measurement is relatively quick and painless.
To avoid an increase in blood pressure due to the "white coat effect", it is necessary to leave the cat quietly in its transport cage for about ten minutes. The measurement of the blood pressure must be done in the presence of the owner. Handling of the cat should be kept to a minimum.
Because blood pressure is more common in older cats, it is recommended that cats over the age of 8 years have their blood pressure measured once a year as part of their health check. When underlying diseases are diagnosed (such as renal failure and hyperthyroidism), more frequent blood pressure checks are recommended.
What are the consequences of high blood pressure?
High blood pressure can lead to damage to the eyes, brain, kidneys and heart. The higher the blood pressure, the greater the risk of damage to these organs.
High blood pressure can result in sudden loss of vision due to bilateral retinal detachment. It can also be responsible for retinal hemorrhages, glaucoma... Hypertension can therefore be detected following the appearance of a sudden blindness in the cat, without any warning sign. Generally, the lesions are too advanced during the consultation and the cat keeps sequels.
Lesions in the brain can lead to convulsions, loss of vision, loss of balance...
High blood pressure can also cause worsening of kidney failure.
What are the treatments?
There are treatments for high blood pressure in cats. They must be associated with the treatment of the underlying disease (renal insufficiency for example).
A follow-up of the blood pressure is necessary following the implementation of the treatment.