A heart monitoring sensor having a printed circuit board with a depressed inner area, which, together with a flexible bulb extending from a perimeter for the depressed area, forms a sealed cavity. A sensor, such as a pressure sensor, is mounted within the sealed cavity. The bulb is releasably attached to the exterior of an animal near a heart pulse-detection point, and pressure changes within the cavity from the animals heart pulse are sensed by the pressure sensor. The sensor output is provided outside the heart monitor by wired or wireless connection. In a particular embodiment, the sensor may be an active ranging sensor, and may range off of a reflective inner surface of the bulb. The active ranging sensor may be sonar, light reflective, (such as lidar), or Doppler. For a horse, the preferred location is in a natural depression underneath the horses tail near the horses dock.
