Saliva is a multifaceted biological fluid that predominantly originates from the secretions of salivary glands, comprises a diverse analyte of interest such as glucose, lactate, ascorbic acid, uric acid, hormones, DNA, RNA, bacteria, proteins, viruses, enzymes etc. These components exhibit variations in concentration, serve as potential biomarkers for detecting animal disease (Zhou and Liu, 2023). Additionally, the pH level of saliva provides crucial insights into animal health status. For instance, a condition like acidosis can trigger a change of pH in saliva (Castillo-Lopez et al., 2021). Therefore, salivary glucose and pH levels could potentially serve as early-stage biomarkers for detecting BRD and diarrhoea in calves, as well as for monitoring therapeutic responses. Commercially available glucose meters are widely used for their compact size, ease of operation, quantitative results, and high accuracy . However, these devices typically require invasive sample collection methods, which can cause significant discomfort and pain when performed multiple times daily. Moreover, the glucose concentrations in calf saliva are significantly lower than those in capillary blood (2.22-3.33 mM glucose) (Contreras-Aguilar et al., 2021; . Additionally, the effectiveness of these devices is limited and ability to selectively identify glucose even in the presence of physiological interferents such as ascorbic acid (AA) and uric acid (UA) . These interferents have a tendency to interfere with chemical sensing outcomes by obstructing the active sites of electrode surfaces. Although non-enzymatic glucose sensors have been explored, they present several drawbacks including poor stability, low reproducibility, limited linear range, and reduced sensitivity . As a result, non-invasive enzymatic glucose monitoring is considered the most suitable solution to these limitations, offering enhanced selectivity, higher sensitivities, and prolonged stability (Arakawa et al., 2020). However, enzymatic sensors have limitations due to their reliance on an oxygen source or mediators like ferrocenium and quinones, which facilitate electron transfer by shuttling electrons between the enzyme and the electrode. This can be addressed by electrochemically generating molecular oxygen near the sensor electrode by controlling the local pH (O'Sullivan et al., 2021). Among the different biofluids (including saliva, sweat, and tears) that can be non-invasively collected, saliva emerges as the most easily accessible and simplest to extract, while also containing animal disease biomarkers . Therefore, the development of a reliable and easy-to-use electrochemical non-invasive salivary pH and glucose oxidase (GOx) based glucose measuring device is of paramount importance for ensuring the animal health and well-being.