Blood pressure

Blood pressure is the pressure of blood in the arteries. In cats, high blood pressure, or hypertension, is nearly always secondary, which means another disease causes it. The usual causes are chronic kidney disease and hyperthyroidism. It is uncommon in young healthy cats and becomes more likely with age.

Persistently high pressure can injure organs. The eyes are especially at risk: bleeding or detachment of the retina can cause sudden blindness, with wide pupils or bumping into things. Other effects include thickening of the heart muscle, kidney damage, nosebleeds and, in some cats, nerve signs such as disorientation or seizures. Often the first clue is a problem with the eyes, and sudden loss of sight needs a vet at once.

Vets measure blood pressure with a cuff on a leg or the tail and a Doppler probe or a monitor, much as in people. Stress at the clinic can push readings up, so the vet may repeat them in a quiet room, with the owner present. Cats over about ten years old, and those with kidney or thyroid disease, should be checked regularly, ideally at each wellness exam. If pressure stays high, the vet treats the underlying disease and may prescribe a blood pressure medicine. Ask your vet about checks and treatment targets.