Can Infrared Thermography Be Used To Predict Ear Tags Infections in Lambs

Abstract

Ear tagging is one of the common husbandry procedures that cause not only pain and stress but also tissue reaction and infection. Reliable and non-invasive tools are needed to determine the stress and/or pain resulting from routine husbandry procedures commonly performed in farms. Thermal imaging is a non-invasive diagnostic method used in veterinary medicine. The aim of the study was to determine the usability of infrared thermography in prediction of infections caused by electronic and visual ear tags in lambs. We hypothesized that reactive temperature increase within the first hour in the ear tissue in response to the ear tags would trigger the formation of infection. The study was carried out on Akkaraman lambs (n = 60) reared under rural farm conditions. All lambs at two weeks of age were identified with an electronic ear tag (FDX-B, Allflex) on the left ear and an official plastic ear tag on the right ear. Before tagging, infrared images of the ear region were collected at a consistent distance from the left ear of the animal using an infrared camera (FLIR E50) in the barn. Tag insertion was performed by two practitioners at the same time. An hour after tagging, the thermal measurements of both ears were carried out again with infrared camera. The ears of lambs were individually checked in the week after tagging. The status of ear lesions was monitored until healing (about 8 weeks). Before tagging, the average thermal temperature of the left ear was measured as 16.68 degrees C. Electronic ear tags caused more problems than official ear tags. Infected ear rate in electronic and official ear tags was 80% and 50% respectively. Significant temperature differences existed between infected and non-infected ears (P < 0.05). All ear tags that caused further increase in reactive temperature resulted in an inflammatory reaction. As a result, early detection of inflammation is very crucial in terms of implementation of treatment and animal welfare. Ear lesions caused by ear tags in lambs can be early identified using infrared thermography. The preliminary findings of this study should be supported in subsequent studies.