Hypertension in cats with chronic renal failure or hyperthyroidism

Area of Science:

• Veterinary Medicine
• Cardiology
• Nephrology

Background:

• Hypertension is a recognized complication in feline medicine.
• Both chronic renal failure and hyperthyroidism are conditions associated with elevated blood pressure in cats.

Purpose of the Study:

• To investigate the prevalence of hypertension in cats with naturally occurring renal failure and hyperthyroidism.
• To compare blood pressure measurements in affected cats to those of clinically normal cats.
• To assess the reversibility of hypertension in hyperthyroid cats following treatment.

Main Methods:

• Doppler ultrasonic technique used for indirect measurement of systolic and diastolic blood pressures.
• Study included 28 cats with renal failure, 39 with hyperthyroidism, and 33 normal cats.
• Blood pressure was re-evaluated in a subset of treated hyperthyroid cats.

Main Results:

• Cats with renal failure showed significantly higher systolic (146.6 mmHg) and diastolic (96.6 mmHg) pressures than normal cats (118.4/83.8 mmHg).
• Hyperthyroid cats exhibited significantly higher systolic (167.9 mmHg) and diastolic (111.6 mmHg) pressures compared to normal cats.
• Hypertension was present in 61% of renal failure cats and 87% of hyperthyroid cats.
• Successful treatment of hyperthyroidism led to a significant decrease in systolic blood pressure.

Conclusions:

• Mild to moderate hypertension is prevalent in cats suffering from chronic renal failure.
• Untreated hyperthyroidism is frequently associated with significant hypertension in cats.
• Hypertension in hyperthyroid cats appears to be reversible after effective treatment of the underlying condition.