No-Contact Microchip Monitoring of Body Temperature in Yearling Horses.
Authors: Auclair-Ronzaud Juliette, Benoist Stéphanie, Dubois Cédric, Frejaville Marie, Jousset Tristan, Jaffrézic Florence, Wimel Laurence, Chavatte-Palmer Pascale
Journal: Journal of equine veterinary science
Summary
# No-Contact Microchip Monitoring of Body Temperature in Yearling Horses Temperature-sensitive microchips implanted subcutaneously in the neck offer a non-invasive alternative to rectal temperature measurement, eliminating the handling stress and time demands of conventional clinical assessment. Researchers equipped 43 healthy yearlings (aged 4–12 months) with identification and temperature microchips over two consecutive winters, collecting over 100,000 automated temperature readings via an antenna positioned near the drinking trough whilst simultaneously obtaining 79 rectal temperature measurements for validation. Body temperature in yearlings averaged 37.5°C with marked circadian variation (0.96°C daily amplitude), lowest values before dawn and peak acrophase around 18:00, alongside significant effects of sex (males 0.26°C higher), bodyweight (lighter foals running 0.1°C warmer), and seasonal daylight exposure (declining 0.35°C over the study period). Although correlation between microchip and rectal readings was modest (R² = 0.16), both methods remained significantly correlated and within normal physiological limits, confirming the reliability of the sensor technology. For practitioners, continuous automated temperature monitoring via microchips could facilitate early detection of systemic illness without repeated handling, providing longitudinal baseline data critical for identifying clinically significant deviations whilst accounting for the considerable normal variation driven by circadian rhythms, feeding patterns, and individual characteristics.
Read the full abstract on PubMed
Practical Takeaways
- •No-contact microchip monitoring eliminates need for rectal temperature measurement, reducing handling stress and time required for health monitoring in young horses
- •Account for circadian rhythm (0.96°C daily variation), sex, and body weight when interpreting microchip temperature data to avoid false health concerns
- •This technology enables continuous remote monitoring of normal body temperature baseline, improving early detection of illness without animal disturbance
Key Findings
- •Mean microchip-recorded temperature was 37.5 ± 0.1°C in healthy yearling horses with daily amplitude of 0.96°C (P < .001), lowest before dawn and peak around 18:00
- •Male foals had significantly higher mean temperature than females by 0.26°C (P < .05), and lighter foals (<200 kg) were 0.1°C higher than heavier foals (P < .001)
- •Temperature decreased by 0.35°C over the study period with increasing daylight (P < .001)
- •Microchip and rectal temperatures were significantly correlated (R² = 0.16, P < .001) with 100,000+ non-invasive recordings obtained