To measure your pet's heart rate at home here are a few suggestions.
Start by being in a calm state and comforting your cat or dog, either in your lap or in a safe area that they can relax.
For the heart rate, placing a hand under the chest wall behind the front legs. Thumb on one side and fingers on the other. Light pressure in and out close to the elbows will pick up the beat of the heart between the ribs.
Once detected, maintain an even pressure between the thumb and fingers counting the heart beats for a minute.
When the patient is large, a back leg pulse can also help determine the heart rate. Place a hand hold on the inside of the back leg. Thumb on the outside and fingers on the inside of the upper leg. Light pressure with your fingers feel in the middle area of the thigh. Light pressure in and out should allow for detection of the pulse. Count the beats per minute.
If adventurous, obtain a stethoscope on line. Most of the low cost stethoscopes will be sufficient to count the beats of the heart. Rate will vary through out the day and activities. Stated rates of beats per minute for a cat can be 140- 200 beats per minute, resources on these numbers vary. Learn what is normal for your cat at rest or at play..