Systemic hypertension is elevated blood pressure. We measure blood pressure in millimeters of mercury. Systolic blood pressure is when the heart is pumping at its maximum. Diastolic blood pressure occurs when the heart is at its maximum rest. In dogs and cats, pressure is measured with a blood pressure cuff in a manner similar to that in people, but special equipment must be used to detect blood flow in their tiny arteries. An increase in blood pressure can cause damage to the kidneys, eyes, heart and other organs.
In both dogs and cats, systemic hypertension is associated with chronic kidney disease. In dogs, adrenal gland disease can cause systemic hypertension. In cats, hypertension is a cause. Hypertension is a rare complication of some medications.
Hypertension is confirmed by repeated blood pressure measurements. Once the diagnosis is established, further tests are needed to find the underlying cause. Those include routine laboratory and urine tests, thyroid tests, chest and abdominal X-rays and ultrasound exams.
Treatment is indicated in all affected animals to prevent further damage to various organs from hypertension. The goal is to reduce blood pressure. In dogs and cats, the drug amlodipine is usually prescribed. Often this drug is combined with what are called angiotensin-converting enzyme (ACE) inhibitors. Occasionally, beta-blocker drugs are used in combination with other drugs. Dogs are similar to people in that no single drug works all the time. All these drugs can cause hypotension, so notify your veterinarian if your dog acts weak after starting them.
If a cause of an increased blood pressure is found, then it is also treated. If the underlying cause can be cured, such as hyperthyroidism or Cushing’s disease, then the increased blood pressure will eventually disappear, and anti-hypertensive drugs may be discontinued. Patients with hypertension should be monitored carefully, as their increased blood pressure can cause blindness, strokes and death. Talk to your veterinarian about this occult and dangerous disease.
Dr. Karsten Fostvedt is a veterinarian at St. Francis Pet Clinic in Ketchum.