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

Thermographic Image of the Hoof Print in Leisure and Cross-Country Warmblood Horses: A Pilot Study

BACKGROUND

The field of veterinary medicine lacks information on equine thermal hoof printing, and few data on the same subject are available in dogs. In human medicine, thermography is used to detect heat emitted by the foot when it comes in contact with a flat surface to detect the abnormalities of the foot balance. The hypothesis states that the thermal pattern of the hoof print in Warmblood horses is detectable and it does not vary among the four limbs in leisure and cross-country Warmblood horses in terms of mean temperature of the hoof print surface. A pilot study was conducted to investigate the accuracy of thermography in temperature detection of the hoof print and to investigate the occurrence of possible differences in the mean value of six selected areas and whether there are any differences in the mean temperature of the hoof print between leisure and cross-country Warmblood horses.

METHODS

The study included sixty non-lame Warmblood horses with all limbs taken into consideration (n = 240). The selection criteria for the horses were: no alterations in posture and no muscle group asymmetry during visual examination, no lateral or medial deviation of the carpus or hock, no reaction to the flexion tests, negative reactions to the hoof tester, no lameness during walking, trotting or lunging, no anti-inflammatory medication in the last three weeks prior to examination and rectal temperature between 37 °C and 38 °C. The hoof print of each hoof was measured with the horse in the standing position, all four limbs on the ground, using a FLIR E50 thermal camera. Six areas of temperature from the hoof print were taken into consideration, and for each of them, the mean value was identified using FLIR Tools software for photo interpretation. The One-Way ANOVA test was used to test the differences between the mean temperatures obtained for each selected area from all limbs and to compare the hoof print temperature values between the leisure horses and cross-country horses. Data were statistically processed using SAS Studio.

RESULTS

Thermography can detect the temperature emitted by the hoof but the thermal patterns of the hoof print show no difference for all four studied limbs. No significant statistical differences were noticed between the mean temperatures identified for each studied area. Also, there were no statistical differences between the mean temperature of the selected areas from the forelimbs and hindlimbs from the horses used for leisure and those used for cross-country. Based on this aspect, the mean temperature of one selected area can be determined in any of the four limbs, without visible variations.

CONCLUSIONS

Thermography can detect the hoof print on a flat surface and the mean temperature for each studied area can be proposed as a reference temperature value. There were no differences in the mean temperature of the hoofprint between leisure and cross-country Warmblood Horses. Further investigations are required to clarify whether there are any differences in the thermal pattern of hoof prints from other breeds or from horses with musculoskeletal conditions.

Application of the Two-Dimensional Entropy Measures in the Infrared Thermography-Based Detection of Rider: Horse Bodyweight Ratio in Horseback Riding

As obesity is a serious problem in the human population, overloading of the horse's thoracolumbar region often affects sport and school horses. The advances in using infrared thermography (IRT) to assess the horse's back overload will shortly integrate the IRT-based rider-horse fit into everyday equine practice. This study aimed to evaluate the applicability of entropy measures to select the most informative measures and color components, and the accuracy of rider:horse bodyweight ratio detection. Twelve horses were ridden by each of the six riders assigned to the light, moderate, and heavy groups. Thermal images were taken pre- and post-exercise. For each thermal image, two-dimensional sample (SampEn), fuzzy (FuzzEn), permutation (PermEn), dispersion (DispEn), and distribution (DistEn) entropies were measured in the withers and the thoracic spine areas. Among 40 returned measures, 30 entropy measures were exercise-dependent, whereas 8 entropy measures were bodyweight ratio-dependent. Moreover, three entropy measures demonstrated similarities to entropy-related gray level co-occurrence matrix (GLCM) texture features, confirming the higher irregularity and complexity of thermal image texture when horses worked under heavy riders. An application of DispEn to red color components enables identification of the light and heavy rider groups with higher accuracy than the previously used entropy-related GLCM texture features.

Validation of Eye Temperature Assessed Using Infrared Thermography as an Indicator of Welfare in Horses

This study aimed to validate eye temperature (ET) assessed using infrared thermography (IRT) as an indicator of welfare in horses. Moreover, this study aimed to determine the most accurate position for ET measured using IRT and to validate this approach as a gold-standard measurement method. As the quantitative data obtained by IRT have strongly influenced the ET results depending on the specific location of the measurement area, an accurate definition of the regions of interest (ROI) was established. A total of 176 horses (Thoroughbred, Warmblood, and Halla horses) were used at the racing course of the Korea Racing Authority and public horse-riding clubs in South Korea. The present study also compared temperatures among three ROIs of the eye—lacrimal sac, medial canthus, and lateral canthus—at rest. Correlations between ET, rectal temperature (RT), heart rate (HR), and respiratory rate (RR) were assessed. There were no significant correlations between HR, RR or RT; however, among the three ROIs, the temperature of the medial canthus was positively correlated with RT (p < 0.05). Furthermore, the size of ROI was negatively correlated with accuracy of temperature measurement. These results indicate that the most suitable area for ET measurement using IRT in horses is the medial canthus, and it is recommended to use the average temperature of the smallest ROIs (2 × 2 pixels) for temperature analysis. Therefore, this study offers a validated protocol in which ET measured using IRT in the horses is useful as an indicator of welfare.

The Physical Activity-Dependent Hematological and Biochemical Changes in School Horses in Comparison to Blood Profiles in Endurance and Race Horses

Blood testing is one of the most important ways to improve performance, facilitate recovery and monitor the training of endurance and race horses. However, little is known about the physical activity-dependent changes of blood parameters in horses used for pleasure and in riding schools. This study aimed to perform routine blood tests for training monitoring of sport horses in three different horse types of use. Then the values of blood indicators were compared between school, endurance and race horses to find similarities in the physical activity-dependent profile. The study was carried out on 15 endurance, 15 race and 15 school healthy horses who underwent the typical effort for their disciplines. The hemogram parameters, creatine phosphokinase (CPK), aspartate aminotransferase (AST), blood lactate (LAC), and total serum protein (TSP) concentrations were measured using the same protocol and equipment. Measurements of main hematological and biochemical physical activity-dependent parameters were conducted before, immediately after and 30 min after training. In school horses, the physical activity-dependent increase of WBC (40.9%) and CPK (76.4%) was similar to endurance horses, whereas an increase of RBC (19.1%), HGB (18.6%) and HCT (19.4%) were more similar to race horses. The moderate effort-dependent increase of LAC concentration (2775%) was lower than in race horses (7526%) and higher than in endurance horses (390%). Limiting the training or work monitoring assessment of school horses to only the endurance or racing blood profile may result in the omission of significant changes in hematological and biochemical parameters.

A Systematic Approach to Comparing Thermal Activity of the Thoracic Region and Saddle Pressure Distribution beneath the Saddle in a Group of Non-Lame Sports Horses

Simple Summary

Thermography is a non-invasive method for measuring surface temperatures. Due to its ease of use, it may be a convenient way of identifying hypo/hyperthermic areas under a saddle that may be related to saddle pressures. A thermal camera quantified temperatures at specific locations (left/right) of the thoracic region at three-time points; a Pliance (Novel) pressure mat determined the mean/peak saddle pressures (kPa) during a period of exercise. Differences between saddle widths in the cranial/caudal mean and peak saddle pressures were found. The maximum thermal temperatures increased post lunge and post ridden compared to the baseline. No difference between post lunge and post ridden exercise were found. The thermal activity does not appear to be representative of increased saddle pressure values. The sole use of thermal imaging for saddle fitting should be applied with caution.

Abstract

Thermography is a non-invasive method for measuring surface temperatures and may be a convenient way of identifying hypo/hyperthermic areas under a saddle that may be related to saddle pressures. A thermal camera quantified minimum/maximum/mean temperatures at specific locations (left/right) of the thoracic region at three-time points: (1) baseline; (2) post lunging; (3) post ridden exercise in eight non-lame sports horses ridden by the same rider. A Pliance (Novel) pressure mat determined the mean/peak saddle pressures (kPa) in the cranial and caudal regions. General linear mixed models with the horse as the random factor investigated the time point (fixed factor: baseline; lunge; ridden) and saddle fit (fixed factor: correct; wide; narrow) on thermal parameters with Bonferroni post hoc comparison. The saddle pressure data (grouped: saddle width) were assessed with an ANOVA and Tukey post hoc comparison (p ≤ 0.05). Differences between the saddle widths in the cranial/caudal mean (p = 0.05) and peak saddle pressures (p = 0.01) were found. The maximum temperatures increased post lunge (p ≤ 0.0001) and post ridden (p ≤ 0.0001) compared to the baseline. No difference between post lunge and post ridden exercise (all p ≥ 0.51) was found. The thermal activity does not appear to be representative of increased saddle pressure values. The sole use of thermal imaging for saddle fitting should be applied with caution.

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.

Infrared Thermography Correlates with Lactate Concentration in Blood during Race Training in Horses

In horse racing the most acceptable way to objectively evaluate adaptation to increased exertion is to measure lactate blood concentration. However, this may be stressful for the horse, therefore, a simple, noninvasive procedure to monitor race progress is desirable. Forty Thoroughbreds attended race training, with blood samples collected at rest, immediately after, and 30 min after exercise. The lactate concentration was determined 60 s after blood collection using an Accusport®. Thermal imaging of the neck and trunk areas was performed following international veterinary standards from a distance of approximately 2 m from the horse using the same protocol as the blood sampling. The Spearman rank correlation coefficients (ρ) between the changes in the blood lactate concentration and surface temperature measures were found for the regions of interest. The highest positive correlation coefficients were found in the musculus trapezius pars thoracica region for the maximal temperature (T Max; ρ = 0.83; p < 0.0001), the minimal temperature (T Min; ρ = 0.83; p < 0.0001), and the average temperature (T Aver; ρ = 0.85; p < 0.0001) 30 min after the exercise. The results showed that infrared thermography may supplement blood measurements to evaluate adaptation to increased workload during race training, however, more research and references values are needed.