Large Animal Surgery and Orthopaedics, University of Veterinary Medicine Vienna (Vetmeduni Vienna), Vienna, Austria.
Equine Vet J. 2013 Sep;45(5):637-41. doi: 10.1111/evj.12019. Epub 2013 Jan 7.
Current literature suggests that thermographic imaging of horses should be performed in a draught-free room. However, studies on the effect of airflow on determined temperature have not been published.
To investigate effects of airflow on thermographically determined temperature of horses' forelimbs; to assess the relationship of wind velocity, rectal temperature, ambient temperature and humidity.
Thermographic images were obtained for the forelimbs of 6 horses in a draught-free room. Three replicates (R) with defined wind velocities (R1, 0.5-1.0 m/s; R2, 1.3-2.6 m/s; and R3, 3.0-4.0 m/s) were conducted. Each replicate consisted of a baseline image, a 15 min phase with the wind on and a 15 min phase with the wind off. We exposed only the right leg to airflow and determined the temperature by thermography with the wind on and wind off. Temperature differences between baseline and wind on, between wind on and wind off and between different wind velocities were analysed by a general linear model, Student's paired t test and ANOVA.
After the onset of wind, the temperature on the right forelimb decreased within 1-3 min (by approximately 0.6°C at R1, 1.5°C at R2 and 2.1°C at R3). With the wind off, the temperature increased within 3 min (by approximately 1.2°C at R1, 1.7°C at R2 and 2.1°C at R3). With increasing wind velocity, the temperature differences between baseline and wind on and between wind on and wind off increased significantly.
Barely noticeable wind velocities caused a decrease in thermographically determined temperatures of the forelimbs of the horse. Further research is required to assess the influence of airflow on other parts of the body and at different ambient temperatures, as well as the effect on horses with inflammatory lesions, especially of the distal limbs.
It is essential for practitioners to perform thermography on horses in a draught-free environment in order to avoid false-positive or -negative diagnoses.
目前的文献表明，对马进行热成像应在无气流的房间中进行。然而，关于气流对确定温度的影响的研究尚未发表。
研究气流对马前肢热成像确定温度的影响；评估风速、直肠温度、环境温度和湿度的关系。
在无气流的房间中对 6 匹马的前肢进行热成像。进行了三个重复（R），风速分别为（R1，0.5-1.0 m/s；R2，1.3-2.6 m/s；R3，3.0-4.0 m/s）。每个重复都包括一个基线图像，一个 15 分钟的有风和一个 15 分钟的无风阶段。我们只让右前肢暴露在气流中，并在有风时和无风时通过热成像确定温度。通过一般线性模型、学生配对 t 检验和方差分析分析基线与有风、有风与无风以及不同风速之间的温差。
在有风开始后，右前肢的温度在 1-3 分钟内下降（在 R1 约为 0.6°C，在 R2 约为 1.5°C，在 R3 约为 2.1°C）。当风停止时，温度在 3 分钟内升高（在 R1 约为 1.2°C，在 R2 约为 1.7°C，在 R3 约为 2.1°C）。随着风速的增加，基线与有风、有风与无风之间的温差显著增加。
几乎察觉不到的风速会导致马前肢的热成像确定温度下降。需要进一步研究气流对身体其他部位和不同环境温度的影响，以及对有炎症病变的马的影响，特别是四肢远端的马。
从业者必须在无气流的环境中对马进行热成像，以避免假阳性或假阴性诊断。
