Ocular lesions associated with systemic hypertension in cats: 69 cases (1985-1998)

Objective-To characterize clinical and clinicopathologic findings, response to treatment, and causes of systemic hypertension in cats with hypertensiv e retinopathy. Design-Retrospective study. Animals-69 cats with hypertensive retinopathy. Procedure-Medical records from cats with systemic hypertension and hyperten sive retinopathy were reviewed. Results-Most cats (68.1%) were referred because of vision loss; retinal det achment, hemorrhage, edema, and degeneration were common findings. Cardiac abnormalities were detected in 37 cats, and neurologic signs were detected in 20 cats. Hypertension was diagnosed concurrently with chronic renal fail ure (n = 22), hyperthyroidism (5), diabetes mellitus (2), and hyperaldoster onism (1). A clearly identifiable cause for hypertension was not detected i n 38 cats; 26 of these cats had mild azotemia, and 12 did not have renal ab normalities. Amlodipine decreased blood pressure in 31 of 32 cats and impro ved ocular signs in 18 of 26 cats. Conclusions and Clinical Relevance-Retinal lesions, caused predominantly by choroidal injury, are common in cats with hypertension. Primary hypertensi on in cats may be more common than currently recognized. Hypertension shoul d be considered in older cats with acute onset of blindness; retinal edema, hemorrhage, or detachment; cardiac disease; or neurologic abnormalities, C ats with hypertension-induced ocular disease should be evaluated for renal failure, hyperthyroidism, diabetes mellitus, and cardiac abnormalities. Blo od pressure measurements and funduscopic evaluations should be performed ro utinely in cats at risk for hypertension (preexisting renal disease, hypert hyroidism, and age > 10 years). Amlodipine is an effective antihypertensive agent in cats.