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Example of thermographic image of the lateral aspect of the right non-pigmented hindlimb fetlock joint taken after HILT. The rectangular area (R1) indicates the average surface temperature of 31.7 • C.
Source publication
The aim of the study was to assess differences in the influence of high-intensity laser therapy (HILT) on the skin surface temperature and vein diameter of the lateral fetlock joint region in a group of racehorses with pigmented and non-pigmented skin in the treatment area. Twenty Thoroughbreds were divided into two equal groups: pigmented and non-...
Context in source publication
Context 1
... distance between the animal and the camera was fixed for all imaging at 0.5 m, and the emissivity (ε) was set to 1 for all readings. The average surface temperature of a rectangular area placed over the shaved area (Figure 1) was calculated using IRBIS 3 Professional software (InfraTec, Dresden, Germany). ...
Citations
... During the study, the stable doors and windows were kept closed to prevent drafts and exposure to direct sunlight. On the day of the examination, the horses were at rest, before training, brushed an hour before the study, and without the application of ointments or blankets on the day prior to the procedure (7,28). The examination procedure for each horse was conducted in its box, allowing a 20-minute acclimatization period (25). ...
Vascular physical therapy (BEMER) is a technology employing low-frequency pulsed electromagnetic fields to enhance microcirculation. The objective of this pilot study was to evaluate the effects of BEMER therapy on body surface temperature changes in the upper limb and dorsal regions of racehorses. The study involved 14 horses divided into an active BEMER group (n = 7) and a sham group (n = 7). Body surface temperature measurements were taken bilaterally from the lateral aspect at three time points: just before therapy, just after therapy, and 15 minutes after therapy. In each thermographic image, measurement regions were designated for the following muscles: the triceps brachii, the longissimus thoracis, and the quadriceps femoris, from which the average temperature was calculated. The findings revealed no increase in body surface temperature immediately after therapy in either group. However, 15 minutes after therapy the body surface temperature in the active BEMER group was significantly higher compared to that in the sham group, in which temperature decreased. BEMER therapy maintained a stable surface body temperature for up to 15 minutes after therapy, despite exposure to a lower ambient temperature (24°C).
... IRT can play a role in evaluating therapeutic devices for equine physiotherapy. Previous studies have assessed the effect of laser therapy [23,24] and extracorporeal shock wave therapy [25] on body surface temperature in the distal parts of the forelimbs. All of these studies have demonstrated the utility of IRT in the assessment of temperature changes in response to therapy. ...
... The captured images were processed using software (IRBIS 3 Professional, InfraTec, Dresden, Germany) by one person to determine the average body surface temperature of the selected four regions of interest (ROIs): cannon bone, fetlock joint, fetlock bone and hoof ( Figure 2). The shaved area with applied gel was avoided in temperature measurements [23,24]. The ambient temperature in the stable was 20 • C ± 3 • C with a humidity of 50%, measured with a TES 1314 thermometer (TES, Taipei, Taiwan). ...
... The captured images were processed using software (IRBIS 3 Professional, InfraTec Dresden, Germany) by one person to determine the average body surface temperature o the selected four regions of interest (ROIs): cannon bone, fetlock joint, fetlock bone and hoof ( Figure 2). The shaved area with applied gel was avoided in temperature measure ments [23,24]. The ambient temperature in the stable was 20 °C ±3 °C with a humidity o 50%, measured with a TES 1314 thermometer (TES, Taipei, Taiwan). ...
The study aimed to evaluate the impact of BEMER (Physical Vascular Therapy) on body surface temperature using infrared thermography (IRT) in the distal parts of the forelimbs in Thoroughbreds. The study tested the hypothesis that BEMER therapy leads to an increase in body surface temperature and blood vessel diameter in the distal parts of the forelimbs. The study involved 16 horses, split into 2 groups: active BEMER (n = 8) and sham (n = 8). The active BEMER group had BEMER boots applied to the distal parts of the forelimbs, whereas the sham group had BEMER boots applied without activation of the device. Both groups underwent IRT examination to detect changes in body surface temperature, followed by ultrasonographic examination to assess changes in vein and artery diameter before (BT) and just after (JAT) therapy. The IRT examination was repeated 15 min after BEMER therapy (15AT). There were no significant body surface temperature differences between BT and JAT in any regions of interest (ROIs) in either group. In the active BEMER group, the ROIs did not change significantly at 15AT, compared to the temperatures measured at BT (except for the hooves). At 15AT the temperature of all the ROIs (except the fetlock bone) dropped significantly in the sham group. In the ultrasonographic examination, there was a significant increase in vein and artery diameter in the study group JAT, whereas the sham group had a significant increase only in artery diameter JAT. These results suggest an effect of BEMER on stimulating blood circulation in the distal parts of the forelimbs in clinically healthy horses. IRT did not identify changes in skin surface temperature after BEMER therapy at the distal parts of the forelimbs.
... Generally, four types of temperature sensor equipment ar employed in thermoregulation research: thermometers, thermistors, thermocouples, and infrared thermography (IRT) devices. Of these, IRT has received the most extensiv attention in recent equine studies and is commonly used remotely (non-contac temperature sensor) [22,[44][45][46][47][48][49][50][51][52][53][54][55][56]. Digital temperature sensors may include technology tha comprises a logger consisting of a temperature sensor in a stainless-steel computer chip with an enclosed battery [57]. ...
... Generally, four types of temperature sensor equipment are employed in thermoregulation research: thermometers, thermistors, thermocouples, and infrared thermography (IRT) devices. Of these, IRT has received the most extensive attention in recent equine studies and is commonly used remotely (non-contact temperature sensor) [22,[44][45][46][47][48][49][50][51][52][53][54][55][56]. Digital temperature sensors may include technology that comprises a logger consisting of a temperature sensor in a stainless-steel computer chip with an enclosed battery [57]. ...
Simple Summary
Heat stress is an important performance and welfare issue for exercising horses. The process of thermoregulation is crucial for equine athletes. Excessive metabolic heat generation during exercise, combined with inefficient heat dissipation, can lead to hyperthermia if not detected in time and not effectively managed. Accurately monitoring heat generation during exercise allows for early preventative intervention as body temperature rises. Skin temperature monitoring is commonly used as a non-invasive method to assess body temperature responses pre- and post-exercise. To date, few studies have used infrared thermographic techniques to monitor body temperature continuously during exercise under laboratory conditions and in the field. In reviewing these results, the accuracy of measuring skin temperature as a reliable indication of overall body temperature is discussed. This commentary summarizes the results of studies measuring surface skin temperature in horses, particularly using infrared thermography for exercise-focused monitoring in the field.
Abstract
Hyperthermia and exertional heat illness (EHI) are performance and welfare issues for all exercising horses. Monitoring the thermoregulatory response allows for early recognition of metabolic heat accumulation during exercise and the possibility of taking prompt and effective preventative measures to avoid a further increase in core body temperature (Tc) leading to hyperthermia. Skin temperature (Tsk) monitoring is most used as a non-invasive tool to assess the thermoregulatory response pre- and post-exercise, particularly employing infrared thermographic equipment. However, only a few studies have used thermography to monitor skin temperature continuously during exercise. This commentary provides an overview of studies investigating surface skin temperature mainly by infrared thermography (IRT) during exercise. The scientific evidence, including methodologies, applications, and challenges associated with (continuous) skin temperature monitoring in horses during field exercise, is discussed. The commentary highlights that, while monitoring Tsk is straightforward, continuous Tsk alone does not always reliably estimate Tc evolvement during field exercise. In addition, inter-individual differences in thermoregulation need to be recognized and accounted for to optimize individual wellbeing. With the ongoing development and application of advanced wearable monitoring technology, there may be future advances in equipment and modeling for timely intervention with horses at hyperthermic risk to improve their welfare. However, at this point, infrared thermographic assessment of Tsk should always be used in conjunction with other clinical assessments and veterinary examinations for a reliable monitoring of the welfare of the horse.
... Skin surface temperature evaluation provides valuable information for monitoring the physiological status of an animal, which is influenced by local metabolism, blood flow (vascular tone), perfusion in subcutaneous tissue, the metabolic activity of the muscles and coat thermal insulation properties [32][33][34]. Previous studies have highlighted the potential use of thermography for monitoring the rehabilitation effects of physical devices, such as laser and electromagnetic field therapy in healthy horses [35][36][37]. In a study presented by Lubkowska et al. [38] rESWT caused increased skin surface temperature in the infraspinatus muscle region immediately after treatment and 15 min after rESWT. ...
Radial extracorporeal shock wave therapy (rESWT) is increasingly being used to treat musculoskeletal injuries in horses. The aim of this study was to assess the influence of rESWT on the skin surface temperature of the longissimus dorsi muscle in clinically healthy racing horses. A total of 24 thoroughbreds were divided into a study group (n = 12) and an rESWT-sham group (n = 12). The study group underwent rESWT, whereas the rESWT-sham group had rESWT without probe activation in the treated area. Both groups underwent thermographic examination before and just after rESWT to determine and compare skin surface temperatures. Palpation examination was performed after the first and second thermography examination to assess longissimus dorsi muscle tone. Additionally, thermographic examination was repeated 10 min after the rESWT. In both groups, there was an increase in skin surface temperature just after rESWT, and a decrease 10 min after it to below the initial value. In the study group, the skin surface temperature just after rESWT was higher than in the rESWT-sham group. Additionally, in the study group the average muscle tone before rESWT was significantly higher than just after the procedure, whereas in the rESWT-sham group the average change in muscle tone was not significant. The results proved that rESWT increases skin surface temperature of the longissimus dorsi muscle in clinically healthy horses. Further research is necessary in order to configure shockwave treatment with appropriate parameters for effective and safe therapy.
... There have been several recent animal studies that have investigated thermal effects associated at a single wavelength, as well those experienced with dual wavelength approaches to PBMT. Zielinska et al. investigated high-intensity laser therapy (HILT) in healthy pigmented and non-pigmented horses, with experiments performed on shaved fur measuring temperature rises, and vein diameters using a surface thermal camera and ultrasound [71]. A 5 cm 2 probe in scanning mode was applied with an 808 nm laser source set at an average power of 4 W, with 2 kHz applied to an area of 26 cm 2 over 203 s, a process delivering a total of 650 Joules. ...
Citation: Cronshaw, M.; Parker, S.; Grootveld, M.; Lynch, E. Abstract: The purpose of this study was to investigate photothermal aspects of photobiomodu-lation therapies (PBMT) in vitro to assist in the development of safe clinical parameters with respect to higher-power devices with large surface applicators. Laser wavelengths in the range of 650 nm-1064 nm were investigated using a thermal camera. Thermographic measures of surface and sub-surface temperature variations of similar lean porcine muscle tissue samples were recorded for a series of calibrated experiments. A thermal comparison was then made between Flat-top and Gaussian beam spatial distribution devices. Outcome data were subjected to statistical analysis using an ANOVA model. Results acquired at similar parameters of irradiance indicated that the application of the 980 nm wavelength was associated with the highest rise in temperature, which decreased with other wavelengths in the order 980 > 1064 ≈ 650 >>> 810 nm (p < 5 × 10 −20). All wavelengths assessed were associated with a significant temperature increase, and with the exception of 810 nm, all exceeded the threshold of a 6 • C rise within the prescribed parameter limits. Optical scanning by movement of the applied source over a relevant area was found to offer effective mitigation of these temperature increases. An extended discussion is presented, analysing the clinical significance of the study outcomes. Recommendations are made within the limits of this in vitro study in order to assist future clinical investigations.
... This results in a hastened removal of inflammatory cytokines, improvement in the mitochondrial oxidation process, production of adenosine triphosphate, and more efficient absorption of tissue swelling [46]. In the current study, we did not control the presence and degree of vasodilatation, although our previous research confirmed vessel diameter increase in irradiated tissue immediately after HILT [47,48]. ...
The reason for undertaking this study was to investigate soft tissue response to high-intensity laser therapy (HILT) by measuring changes in skin surface temperature and longissimus dorsi muscle tone in the thoracolumbar back area in Thoroughbreds with back pain and diagnosed with and without Kissing Spines Syndrome (KSS). Thoroughbreds aged 3–4 years with clinically presented back pain underwent a radiological examination (to assess a lack or presence of KSS) and longissimus dorsi muscle palpation (to assess muscle tone and pain degree). The subjects were divided into two groups, those with KSS (n = 10) and those without KSS (n = 10). A single HILT treatment on the longissimus dorsi muscle, on the left side, was performed. Thermographic examination and palpation were repeated before and after HILT to assess changes in skin surface temperature and muscle pain response. In both groups, HILT caused a significant increase in skin surface temperature of 2.5 °C on average and a palpation score reduction of 1.5 degrees on average (p = 0.005 for both measurements), without differences in any outcome measures between the groups. Furthermore, the correlation between changes in the average skin surface temperature and the average palpation scores in horses with and without KSS were negative (rho = 0.071 and r = −0.180, respectively; p > 0.05). The results of the present study are encouraging, but further studies with larger samples, a longer follow-up period and comparisons with placebo control groups are needed to draw a more valid conclusion.
... In a previous study, we demonstrated that after HILT, the temperature of the pigmented skin surface increases, while the temperature of the non-pigmented skin surface decreases. In addition, the vein diameter was found to increase after HILT in horses with both pigmented and non-pigmented skin, although the variations between the groups was not significant [21]. It is therefore clear that the amount of melanin in the epidermis has a key role in the absorption of light energy. ...
... The horses of both groups were subjected to an examination procedure based on previous studies [21,24]. On the day of the examination, each horse was first subjected to a thermographic and then to an ultrasonographic recording. ...
... The thermographic examination was performed with a VarioCam HR infrared camera (uncooled microbolometer focal plane array; resolution, 640 × 480 pixels; spectral range, 7.5-14 mm; InfraTec, Dresden, Germany). The protocol for the examination was the same as previously described by Zielińska et al. [21] and Soroko et al. [25]. To minimize environmental influences, the examinations were always performed in an enclosed stable. ...
The aim of this study was to investigate the differences in the effects of high-intensity laser therapy (HILT) on skin surface temperature and vein diameter in the carpal joint region in racehorses with clipped and non-clipped treatment areas. The study included 20 Thoroughbreds split into two equal groups: clipped coat and non-clipped coat. Horses underwent thermographic examination to detect changes in skin surface temperature at the medial surface of the carpal joint, followed by ultrasonographic examination to assess changes in the diameter of the medial palmar vein before and after HILT. The increase in skin surface temperature after HILT was significantly lower in the group with clipped coat than in the non-clipped group. The group with clipped coat showed a greater increase in vessel diameter. There was a significantly weak negative correlation between the changes in average skin surface temperature and vein diameter in both groups. In conclusion, an efficient photothermal effect can be achieved in skin with a non-clipped coat and clipping the treatment area increases photobiostimulation of the tissue, while reducing the photothermal effect. Further research is needed to specify the parameters for the treatment of skin with clipped and non-clipped coat in order to perform effective laser therapy.
... In the search to aid the repair of defects, GaAIAs laser photobiomodulation therapy has been indicated as an adjunct to the surgical technique because it is able to reach deeper tissues because of malabsorption by water and skin pigments [40,41]. In this study, the therapy started after the surgical procedure because it is believed that a laser exerts better results in the initial phase of repair, since research in the area has a preference for postoperative transcutaneous irradiation for increasing angiogenesis, gene expression, and proteins intrinsically related to the bone repair process [42,43]. ...
In this preclinical protocol, an adjunct method is used in an attempt to overcome the limitations of conventional therapeutic approaches applied to bone repair of large bone defects filled with scaffolds. Thus, we evaluate the effects of photobiomodulation therapy (PBMT) on the bone repair process on defects filled with demineralized bovine bone (B) and fibrin sealant (T). The groups were BC (blood clot), BT (B + T), BCP (BC + PBMT), and BTP (B + T + PBMT). Microtomographically, BC and BCP presented a hypodense cavity with hyperdense regions adjacent to the border of the wound, with a slight increase at 42 days. BT and BTP presented discrete hyperdensing areas at the border and around the B particles. Quantitatively, BCP and BTP (16.96 ± 4.38; 17.37 ± 4.38) showed higher mean bone density volume in relation to BC and BT (14.42 ± 3.66; 13.44 ± 3.88). Histologically, BC and BCP presented deposition of immature bone at the periphery and at 42 days new bone tissue became lamellar with organized total collagen fibers. BT and BTP showed inflammatory infiltrate along the particles, but at 42 days, it was resolved, mainly in BTP. In the birefringence analysis, BT and BTP, the percentage of red birefringence increased (9.14% to 20.98% and 7.21% to 27.57%, respectively), but green birefringence was similar in relation to 14 days (3.3% to 3.5% and 3.5% to 4.2%, respectively). The number of osteocytes in the neoformed bone matrix proportionally reduced in all evaluated groups. Immunostaining of bone morphogenetic protein (BMP—2/4), osteocalcin (OCN), and vascular endothelial growth factor (VEGF) were higher in BCP and BTP when compared to the BC and BT groups (p < 0.05). An increased number of TRAP positive cells (tartrate resistant acid phosphatase) was observed in BT and BTP. We conclude that PBMT positively influenced the repair of bone defects filled with B and T.
... However, in that respect, the critical question remains: how should we interpret those data? Overall, three different types of temperature sensor equipment are reported: thermistors (such as microchips), thermocouples, and IRT devices, with IRT being the most studied device recently in horses (21,22,26,(32)(33)(34)(35)(36)(37)(76)(77)(78)(79)(80). It is essential to understand that those sensors use different physical processes to obtain data, which may result in significant differences in data output. ...
Hyperthermia is a performance and welfare issue for exercising horses. The thermoregulatory stressors associated with exercise have typically been estimated by responses in the laboratory. However, monitoring surface skin temperature (Tsk) coincident with core temperature (Tc) has not previously been investigated in horses exercising in the field. We investigated the suitability of monitoring surface Tsk as a metric of the thermoregulatory response, and simultaneously investigated its relationship with Tc using gastrointestinal (GI) temperature. We evaluated Tsk in 13 endurance horses competing during four endurance rides over 40 km (n = 1) or a total of 80 km (n = 12) distance. Following each 40-km loop, the horses were rested for 60 min. Tsk and Tc were continuously recorded every 15 s by an infrared thermistor sensor located in a modified belt and by telemetric GI pill, respectively, and expressed as mean ± SD. The net area under the curve (AUC) was calculated to estimate the thermoregulatory response to the thermal load of Tsk over time (°C × minutes) using the trapezoidal method. The relationship between Tsk and Tc was assessed using scatterplots, paired t-test or generalized linear model ANOVA (delta Tsk) (n = 8). Ambient temperature ranged from 6.7°C to 18.4°C. No relationship was found between Tsk and Tc profiles during exercise and recovery periods, and no significant difference between delta Tsk results was detected when comparing exercise and rest. However, time to maximum Tsk (67 min) was significantly reduced compared to Tc (139 min) (p = 0.0004) with a significantly lesser maximum Tsk (30.3°C) than Tc (39°C) (p = 0.0002) during exercise. Net AUC Tsk was 1,164 ± 1,448 and −305 ± 388°C × minutes during periods of exercise and recovery, respectively. We conclude that Tsk monitoring does not provide a reliable proxy for the thermoregulatory response and horse welfare, most probably because many factors can modulate Tsk without directly affecting Tc. Those factors, such as weather conditions, applicable to all field studies can influence the results of Tsk in endurance horses. The study also reveals important inter-individual differences in Tsk and Tc time profiles, emphasizing the importance of an individualized model of temperature monitoring.
... We found an increase in the body surface temperature of horses with pigmented skin and a decrease in horses with non-pigmented skin. Although the vein diameter in both groups increased after HILT, the differences between groups were statistically insignificant [24]. ...
The aim of the present study was to assess the photothermal effects of high-intensity laser therapy (HILT) on the superficial digital flexor tendon (SDFT) of the hindlimb in racehorses. It was conducted on 18 clinically healthy thoroughbreds that were subjected to thermographic examination to measure surface temperature changes in the SDFT. This was performed before and immediately after HILT. This revealed statistically significant differences in the temperature of the skin surface overlying the flexor tendons (p < 0.001). The surface temperature of the area examined was higher by an average of 3.5 °C after HILT, compared with the temperature measured before HILT. Our results prove that HILT has a photothermal effect in treating soft tissue. This finding can be helpful in determining the appropriate parameters for monitoring the short- and long-term effects of HILT.
