Systems and methods for animal health monitoring are described. In one embodiment, an animal health monitoring system includes a ruminant bolus transponder, a high frequency radio frequency transceiver device, and at least one base station including a high frequency radio frequency transceiver, wherein the high frequency radio frequency transceiver device is proximally located to the bolus transponder, wherein the ruminant bolus periodically emerges from a low power dormant state and measures data including at least one sensor measurement including time and date data, wherein the ruminant bolus is configured to store the measured data using the memory connected to the microcontroller in the ruminant bolus, wherein the ruminant bolus periodically emerges from a low power dormant state and transmits the stored data in the memory to the proximally located device via high frequency RF transmission, and wherein the ruminant bolus can be spontaneously activated by a low frequency scanner.
