TY - JOUR AU - Bleul, Ulrich; Hässig, Michael; Kluser, Fabienne TI - Anwendung einer kleinen tragbaren Wärmebildkamera zum Screening auf Kühe mit Fieber TT - Screening of febrile cows using a small handheld infrared thermography device SN - 1434-1220 SN - 2567-5834 PY - 2021 JO - Tierarztl Prax Ausg G Grosstiere Nutztiere JF - Tierärztliche Praxis Ausgabe G: Großtiere / Nutztiere LA - DE VL - 49 IS - 01 SP - 12 EP - 20 DA - 2021/02/15 KW - Infrared thermography KW - smart phone KW - health monitoring KW - fever KW - body regions KW - surface temperature AB - Objective As dairy herds increase in size, close monitoring of health becomes a necessity, but this is expensive and labour-intensive. Early detection of febrile diseases is essential for economical and welfare reasons and to prevent the spread of disease. The goal of this study was therefore to evaluate a mobile, non-invasive technique for measuring the body temperature of cows that precludes the need for restraint of the animals.Materials and methods An infrared thermographic imaging camera installed on a smart phone was used to measure the surface temperature of cows. In experiment 1, a metal block heated to defined temperatures was used to obtain infrared thermographic measurements (THM). The accuracy of THM made at different distances from the block and at 2 different ambient temperatures was determined. In experiment 2, non-febrile cows underwent infrared thermographic imaging, and the body regions with the highest correlations between thermographic and rectal temperature were identified. In experiment 3, THM were made in febrile and neighbouring non-febrile cows.Results In experiment 1, the thermographic and true temperatures of the block had the strongest relationships at 0.5 and 1.0 m (r = 0.98). The ambient temperature had a significant effect on the THM, which had larger variations and greater deviations from the block temperature at 14.8 °C than at 23.8 °C. In experiment 2, the maximum temperature at the eye (r = 0.37), THM at the muzzle (r = 0.28) and the medial canthus (r = 0.27) showed the strongest relationships with the rectal temperature. After correcting the THM with the mean difference between thermographic and rectal temperatures of the non-febrile cows, sensitivities of 88, 90 and 82 %, respectively, were calculated for THM at the muzzle, eye and medial canthus in febrile cows in experiment 3. The corresponding specificities were 6, 23 and 32 %.Conclusion and clinical relevance Based on the low specificities of the infrared THM, the thermographic imaging camera has limited usefulness for the mass screening of dairy cows for febrile conditions. Cattle falsely identified as febrile need to be separated, caught and re-examined, which causes unnecessary stress to the animal and increases labour input. PB - Georg Thieme Verlag KG DO - 10.1055/a-1307-9993 UR - http://www.thieme-connect.de/products/ejournals/abstract/10.1055/a-1307-9993 ER -