Blood Pressure Is Important in Pets Too.

You can't measure blood pressure in dogs and cats like nurses do in humans, with an inflatable cuff and a stethoscope. The sounds the nurse listens for are inaudible in dogs and cats. For years we have used a cumbersome Doppler machine with an electronic amplifier instead of a stethoscope, but that was noisy and finicky to use. But in recent years the automatic machines have been adapted and refined so they are fairly consistent and accurate in dogs and cats.

Hypertension, high blood pressure, is not the common nemesis of old age in dogs and cats that it is in humans but blood pressure is an important piece of information in managing many diseases and procedures.

Josie is a little Boston Terrier. During her hysterectomy last week we noticed that even though she seemed to be handling the anesthesia fine, and her electrocardiogram and blood oxygen monitors were normal, her blood pressure was low. We increased the rate of her intravenous fluids and her blood pressure came right back up to normal. She probably would have done all right without that added safety measure, but better safe than sorry.

Woody is one of our geriatric patients, an elderly black cat. He had hyperthyroidism several years ago and we removed his thyroid glands. On his annual physical we found Woody to have slightly elevated blood pressure. Woody probably has extra thyroid tissue growing in his chest cavity. Hypertension is common in cats with hyperthyroidism and can cause them to go blind. Woody does not need to be on blood pressure pills now, but we will check his blood pressure regularly in the future.

Brandy, a Springer Spaniel, is another geriatric patient. She has congestive heart failure. She is on two different medications for that, and they both can cause low blood pressure. By checking Brandy's blood pressure regularly, we can do a better job of keeping the dose of her drugs at the optimal level, to keep her from coughing without causing dangerously low blood pressure.

Kidney failure is very common in older dogs and cats. It is incurable, but if it is managed properly the patient can live comfortably for years. High blood pressure is a possible complication that should be avoided but on the other hand it is very important to take special care to avoid low blood pressure if anesthesia is required in a patient with bad kidneys.

Until the use of the MRI in veterinary medicine, strokes were thought to be extremely rare in dogs and cats. Doing an MRI has become an almost routine part of the diagnostic workup for dogs and cats with disorders of the central nervous system and they are finding that strokes are more common than previously thought. It is not known if hypertension causes strokes in pets.

Monitoring blood pressure is especially important in dogs and cats that are critically ill or suffer major trauma. A drop in blood pressure can indicate shock or internal bleeding. Dogs that are hit by cars often develop abnormal heartbeats that can be fatal if unrecognized. A drop in blood pressure may be a warning signal.

Managing life threatening abnormalities in blood pressure may require, beside intravenous fluids, drugs that change the heart rate and the force of heart contractions, and drugs that dilate or constrict the arteries and veins. To use these drugs safely and effectively continuous monitoring of blood pressure is crucial.

Blood pressure is an important "vital sign" in human medicine. The development of automatic instruments to conveniently measure and monitor blood pressure has been a welcome improvement in veterinary medicine.