A novel approach to thermographic images analysis of equine thoracolumbar region: the effect of effort and rider's body weight on structural image complexity

BACKGROUND

The horses' backs are particularly exposed to overload and injuries due to direct contact with the saddle and the influence of e.g. the rider's body weight. The maximal load for a horse's back during riding has been suggested not to exceed 20% of the horses' body weight. The common prevalence of back problems in riding horses prompted the popularization of thermography of the thoracolumbar region. However, the analysis methods of thermographic images used so far do not distinguish loaded horses with body weight varying between 10 and 20%.

RESULTS

The superficial body temperature (SBT) of the thoracolumbar region of the horse's back was imaged using a non-contact thermographic camera before and after riding under riders with LBW (low body weight, 10%) and HBW (high body weight, 15%). Images were analyzed using six methods: five recent SBT analyses and the novel approach based on Gray Level Co-Occurrence Matrix (GLCM) and Gray Level Run Length Matrix (GLRLM). Temperatures of the horse's thoracolumbar region were higher (p < 0.0001) after then before the training, and did not differ depending on the rider's body weight (p > 0.05), regardless of used SBT analysis method. Effort-dependent differences (p < 0.05) were noted for six features of GLCM and GLRLM analysis. The values of selected GLCM and GLRLM features also differed (p < 0.05) between the LBW and HBW groups.

CONCLUSION

The GLCM and GLRLM analyses allowed the differentiation of horses subjected to a load of 10 and 15% of their body weights while horseback riding in contrast to the previously used SBT analysis methods. Both types of analyzing methods allow to differentiation thermal images obtained before and after riding. The textural analysis, including selected features of GLCM or GLRLM, seems to be promising tools in considering the quantitative assessment of thermographic images of horses' thoracolumbar region.

The Effect of Lunging with Three Aids on the Thermographically Determined Temperatures of the Distal Portion of Horse Limbs

The regulation of head and neck position during physical exercise may be obtained using lunging aids (LAs): Chambon (CH), rubber band (RB), or triangle side reins (TR). The use of LAs would shift the center of horse mass caudally, thereby change the limb load. The aim is to evaluate the pattern of superficial temperatures (PST) of hoof wall (HW), the coronary band (CB), and the dorsal aspect of the fetlock joint (FJ) obtained before and after lunging with LAs and freely moving head (FMH). Sixteen horses were imaged using an infrared camera. The temperatures of HW, CB, and FJ were measured, and differences between images obtained before and after lunging were evaluated. The correlations between HW, CB, and FJ were then described using respective coefficients (r, rho). Before lunging PST was similar (P < .05) in FMH, CH, RB, and TR, with the strong positive correlations for forelimbs (HW/CB:rho = 0.9022; HW/FJ:rho = 0.7064; CB/FJ:rho = 0.8010) and hindlimbs (HW/CB:rho = 0.7287; HW/FJ:r = 0.7831; CB/FJ:r = 0.7233). After lunging, PST and correlations changed (P > .05) depending on LAs application. No correlations for FMH and CH, and positive correlations for RB and TR were noted: HW/CB for forelimbs (RB:r = 0.6813; TR:r = 0.8396), CB/FJ for hindlimbs (RB:r = 0.5621; TR:rho = 0.4579). The PST of the distal portion of limbs and relations between measured temperatures change depending on used LAs.

Horse Behavior, Physiology and Emotions during Habituation to a Treadmill

A treadmill is an important tool in the equine analysis of gait, lameness, and hoof balance, as well as for the evaluation of horse rehabilitation or poor performance including dynamic endoscopy. Before all of these uses, horses have to be habituated to a treadmill locomotion. We used principal component analysis to evaluate the relationship between aspects of the horse's temperament and emotional response, and progress in the behavioral habituation to a treadmill. Fourteen horses were tested, by the same familiar handler, using the novel object test, the handling test, and both positive and negative emotional response tests. Then, four stages of gradual habituation of the first work on a treadmill were conducted. Each time, the horse's behavior was filmed. Data obtained from ethograms and heart rate measurements were tested. Four principal components were identified in examined horses: "Flightiness," "Freeziness," "Curiosity," and "Timidity." Flightiness was connected with nervousness, agitation by new objects, and easy excitability, and gradually decreased of features during habituation. Timidity was associated with a lack of courage and stress in new situations, and those features strongly increased when the treadmill was introduced. Freeziness and Curiosity features showed strong stability throughout the whole habituation. The results of this study provide evidence for a connection between temperament, emotional response, and habituation process in a horse.

An application of temperature mapping of horse's back for leisure horse-rider-matching

Leisure riding is a popular way of using horses however, unlike sport or racing horses, those are mostly not associated with one rider with high skills. Constant overload of equine musculoskeletal system causes pathologies, which are affecting horse mobility and decreases the horse-rider communication. The aim was to propose the new scoring system of thermograph analysis as an aspect of differences in heat distributions on horseback before and after leisure ridings. The study was conducted on sixteen Polish warmblood horses, scanned with a non-contact thermographic camera. Heat pattern of the thoracolumbar area was evaluated on thermograms taken before and after exercise. The criteria with point values for horse-rider-matching were created: heat points on the dorsal midline of saddle-back contact area and degree of muscle unit overload. The results of thermograph analysis were compared with the results of a questionnaire on horse-rider communication during riding in order to estimate the relevance of matching. The maximum score was obtained in 38.3% and 39.8% of combinations based on the thermograph analysis and questionnaire, respectively. Results of both scoring systems were strongly positive correlated (r = .937), demonstrating high sensitivity (61.72%) and specificity (90.23%) of the matching. The horse-rider matching may improve horse comfort during leisure type of work.