High Blood Pressure in Cat's: High blood pressure is one of the top 5 most common conditions in older cats, it frequently has no noticeable signs early in the disease. Longer term high blood pressure can cause sudden and serious onset of signs including vision loss. Can high blood pressure affect my cat's behaviour? Cats with high blood pressure may sleep more and appear to be slowing down, they may be more vocal, they may appear confused but often there will be no noticeable signs of high blood