The heart is stimulated to pump faster and more forcefully, much like hypertrophic cardiomyopathy. This results in a greater output of blood and high blood pressure. Hyperthyroidism is a fairly common disease of older cats. If any of these are diagnosed, the cat's blood pressure will be checked, if the equipment is available. If a sudden onset of blindness occurs and the blood pressure is found to be abnormally high, the other conditions are considered as possible underlying causes.
Blood pressure is determined with a device that can detect blood flow in arteries.
However, the cat has very small arteries compared to humans. Therefore, the standard blood pressure equipment used on humans will not work on cats. Only two blood pressure machines have been found reliable in cats. One costs several hundred dollars and the other several thousand. Thus, the expense in purchasing this equipment, coupled with the relative infrequency of hypertension, makes ownership of blood pressure equipment prohibitive for many veterinarians.