Early detection of infectious diseases in animal health, such as Borvine Viral Diarrhoea, is essential to prevention of widespread disease. This paper presents a current readout circuit for interfacing with electrochemical biosensors for point-of-care BVD diagnostics. Focusing on electrochemical impedance spectroscopy measurements, the circuit is composed of a capacitive transimpedance amplifier with a reset switch, and a 12bit SAR ADC. The paper highlights some of the challenges of interfacing with electrochemical sensors for EIS measurements such as flicker noise at low frequencies. An alternative sampling method similar to correlated double sampling is presented, which can be seen to significantly reduce flicker noise without the need for additional chopping.