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.
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?
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?
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.
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.