An animal health monitoring system, comprising: an electronic assembly (104; 201; 402) designed to be located on a companion animal, comprising: a microprocessor ; a power source connected to the microprocessor; and a transceiver ; a microchip designed to be implanted in the companion animal and comprising: memory storing identification data; and a temperature sensor measuring the temperature of the companion animal; wherein said system also comprises: a collar designed to be worn by the companion animal, an antenna (105; 205) integrated into the collar, wherein the electronic assembly and the antenna constitute a microchip scanner, wherein the electronic assembly is configured to: interrogate the microchip to obtain identification data and temperature data from the microchip ; and transmit the identification data and the temperature data, characterised in that : the antenna (105; 205) is a loop antenna embedded circumferentially in the collar, and wherein the reading frequency of the microchip is fixed and the microprocessor is configured to adjust the resonance capacitance based on the antenna inductance which depends on the geometry of the collar at the precise moment of reading the microchip . an electronic assembly (104; 201; 402) designed to be located on a companion animal, comprising: a microprocessor ; a power source connected to the microprocessor; and a transceiver ; a microprocessor ; a power source connected to the microprocessor; and a transceiver ; a microchip designed to be implanted in the companion animal and comprising: memory storing identification data; and a temperature sensor measuring the temperature of the companion animal; memory storing identification data; and a temperature sensor measuring the temperature of the companion animal; wherein said system also comprises: a collar designed to be worn by the companion animal, an antenna (105; 205) integrated into the collar, a collar designed to be worn by the companion animal, an antenna (105; 205) integrated into the collar, wherein the electronic assembly and the antenna constitute a microchip scanner, wherein the electronic assembly is configured to: interrogate the microchip to obtain identification data and temperature data from the microchip ; and transmit the identification data and the temperature data, characterised in that : the antenna (105; 205) is a loop antenna embedded circumferentially in the collar, and wherein the reading frequency of the microchip is fixed and the microprocessor is configured to adjust the resonance capacitance based on the antenna inductance which depends on the geometry of the collar at the precise moment of reading the microchip . interrogate the microchip to obtain identification data and temperature data from the microchip ; and transmit the identification data and the temperature data, characterised in that : the antenna (105; 205) is a loop antenna embedded circumferentially in the collar, and wherein the reading frequency of the microchip is fixed and the microprocessor is configured to adjust the resonance capacitance based on the antenna inductance which depends on the geometry of the collar at the precise moment of reading the microchip . <EOS>