Most people are familiar with having their blood pressure taken during their routine physical exams with their doctor; and know that the procedure is very simple. In veterinary medicine however, blood pressure measurement is more difficult. It requires similar equipment, but has greater inherent variables, including patient resistance, so the measurements can be more difficult to obtain and harder to interpret. Because of how valuable the information can be, however, it is important to try to obtain good results. Pets may feel apprehensive about the procedure and this ‘stress level’ can adversely affect the blood pressure results. For this reason, we take a series of measurement readings and then average those readings to obtain final results. Blood pressure measurement for your pet is a much longer and more involved procedure than it is for people.

A number of problems can result in high blood pressures, including hyperthyroidism in cats and renal and heart disease in both dogs and cats. Monitoring the blood pressure during anesthesia can be valuable to alert us if the blood pressure falls, which might indicate shock associated with the anesthesia or some pre-existing medical conditions.

What do the numbers mean?

The pressures measured are the systolic pressure (the pressure from the heart contracting and pushing the blood out of the heart and always the higher and first value reported), the diastolic pressure (the pressure during the rest or filling period of the heart and always the lowest value reported) and the mean pressure which is about halfway between the high and low values.

At Ojai Pet Hospital, our blood pressure monitor is one of the most reliably accurate machines available, and unfortunately, very expensive. It measures the blood pressure much like it is measured in us, by using a cuff to stop the blood flow with pressure and by slowly releasing the pressure it measures when blood flow starts again. The sooner it starts again, the higher the pressure. This technique is called an oscillometric measurement. The machine measures the values and repeats this procedure several times then we average the results.

What are normal blood pressures for dogs and cats?

The normal dog values are about 112 systolic and about 75 diastolic. The normal cat values are about 125 systolic and about 80 diastolic.

In the dog, if the values are greater than 160 systolic or 95 diastolic, then treatment is needed.

In the cat, if the values are greater than 180 systolic or 100 diastolic, the cat is hypertensive enough to require treatment.

If high values are obtained, we allow the pet to relax and repeat the values at least 5-7 times. Over this time frame, the pet should be getting used to the procedure enough that the blood pressures obtained will be more normal for the pet, rather than high due to anxiety.