Journal of Equine Veterinary Science最新文献

{"title":"Injection of the insertion of the collateral ligament of the distal interphalangeal joint in standing horses using the palmar radiographic-guided approach","authors":"C.J. Kirkpatrick ,&nbsp;N.S. Ernst ,&nbsp;T.N. Trumble","doi":"10.1016/j.jevs.2025.105600","DOIUrl":"10.1016/j.jevs.2025.105600","url":null,"abstract":"<div><div>Injury to the collateral ligament (CL) of the distal interphalangeal joint (DIPJ) is recognized as a source of lameness in horses. Intralesional injection has been advocated to increase return to performance. This study was a proof-of-concept study in standing horses to evaluate success of a palmar radiographic-guided approach for injecting insertions of the DIPJ CLs previously described in cadaver limbs. Horses were sedated, nerve blocked, and placed on wooden blocks with the limb to be injected staggered approximately 20 cm cranially to the other limb. The DIPJ CL insertion was injected, using the palmar radiographic-guided technique, with 0.5 ml of new methylene blue (NMB) dye using an 18g, 9 cm spinal needle. The lateral or medial CL was randomly assigned to one forelimb for injection. Lateromedial and dorsopalmar radiographs were taken to confirm correct location of the needle. Following injection, needles were removed, and horses were euthanized. Two hours after euthanasia, the metacarpophalangeal joint was disarticulated, and the hoof wall was removed. The DIPJ, injected CL, and periligamentous structures (PLS) were assessed for presence of NMB dye. A total of 20 CLs, 10 medial and 10 lateral, were injected. Overall, 19/20 (95%) had dye in CL insertions; 4/20 (20%) had dye only in CL insertion, 6/20 (30%) had dye in CL insertion and DIPJ, and 9/20 (45%) had dye in CL insertion and PLS; 1/20 (5%) had dye only in PLS. A palmar radiographic-guided approach using a staggered stance is a reliable, repeatable way to inject DIPJ CL insertions in sedated horses.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"150 ","pages":"Article 105600"},"PeriodicalIF":1.3,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144012236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Does age and parity affect the oxidative profile of pregnant and postpartum mares?","authors":"R․R․ Rosa Filho ,&nbsp;D.S. França ,&nbsp;M.A. Alonso ,&nbsp;A.V. Riccio ,&nbsp;F.J. Affonso ,&nbsp;M.M. Brito ,&nbsp;M.C.P. Francischini ,&nbsp;M. Nichi ,&nbsp;Y. Boakari ,&nbsp;C.B. Fernandes","doi":"10.1016/j.jevs.2025.105597","DOIUrl":"10.1016/j.jevs.2025.105597","url":null,"abstract":"<div><div>During gestation, there is a higher energy demand which increases oxygen requirements. As a result, there is an elevated production of reactive oxygen species. Notably, unlike in horses, the effects of maternal age and parity on women's oxidative profiles are well-documented. Thus, this study aimed to investigate oxidative changes in mares during the last third of gestation and the postpartum period, considering age and parity. Seventeen mares were categorized by age (3-7, 8-11, ≥12 years) and parity (nulliparous, 1-3, 4-6 parities). Oxidative processes were assessed using Thiobarbituric Acid Reactive Substances (TBARS), protein oxidation, total iron, and magnesium. Antioxidant defenses were measured through glutathione peroxidase, glutathione reductase, and superoxide dismutase activities. Results indicated an age and gestational duration interaction, notably with magnesium levels. Glutathione peroxidase levels were higher in older mares, with a time effect observed among groups. Conversely, glutathione reductase, superoxide dismutase, lipid and protein oxidation, and total iron showed no significant variations during the study. In conclusion, maternal age influences glutathione peroxidase and magnesium concentrations during the final trimester of gestation, parturition, and postpartum phases in mares. This research sheds light on oxidative variations in mares during pregnancy and postpartum, offering insights into the role of maternal age in antioxidant mechanisms.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"150 ","pages":"Article 105597"},"PeriodicalIF":1.3,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143983221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differentiation of equine paranasal sinus cysts and progressive ethmoid haematomas on computed tomographic images","authors":"D. Berner ,&nbsp;M. Hellige ,&nbsp;G.G. Harvey ,&nbsp;K. Gerlach ,&nbsp;M. Iglesias-Garcia ,&nbsp;G. Manso-Diaz","doi":"10.1016/j.jevs.2025.105609","DOIUrl":"10.1016/j.jevs.2025.105609","url":null,"abstract":"<div><div>Paranasal sinus cysts (PSC) and progressive ethmoid haematomas (PEH) are regularly observed in the paranasal sinus system. Due to their different prognosis and treatment options, differentiation of both lesions prior to surgery on computed tomographic (CT) images is important for guidance. It was hypothesised that PSC and PEH can be reliably differentiated on CT images. The database of four European equine referral centres were retrospectively searched for horses that had undergone a CT examination of the head and had a confirmed PSC or PEH. Additionally, cases with confirmed sinusitis were selected as control cases. Images were anonymised and evaluated by different observers to investigate their ability to differentiate these diseases. Multiple imaging characteristics were evaluated for all diseases. Ninety-seven horses were included, final diagnosis was PEH in 24, PSC in 28, and sinusitis in 45 horses. Substantial to almost perfect agreement between CT diagnosis and final diagnosis for all three observers was found. Heterogeneity and attenuation of the lesion were graded significantly higher in PEH. Mineralisation within the soft tissue structure, inner and outer distortion of bone and soft tissues, a mineralised wall, and dental distortion were significantly more common in PSC. Only cases that subsequently underwent treatment were included, therefore, most cases were at an advanced stage. Histological examination was not available in all cases. Differentiation between PEH and PSC on CT images was excellent, and the reported different characteristics might help clinicians to distinguish between both diseases.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"150 ","pages":"Article 105609"},"PeriodicalIF":1.3,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143937339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Presumptive Lyme disease-associated eosinophilic synovitis in a horse","authors":"P․ B․ S․ Serpa ,&nbsp;S. Bogers ,&nbsp;C. Byron ,&nbsp;G. Cardona ,&nbsp;M. Patton","doi":"10.1016/j.jevs.2025.105595","DOIUrl":"10.1016/j.jevs.2025.105595","url":null,"abstract":"<div><div>A 1-year-old American Quarter horse was presented with acute onset of right hind lameness. On physical examination, there was synovial effusion of the right tarsocrural joint. Synovial fluid cytology revealed a marked eosinophilic synovitis. Serology indicated evidence of acute and chronic infection with <em>Borrelia burgdorferi</em>, although PCR of the synovial fluid was negative. The filly was treated with phenylbutazone and oxytetracycline, and repeated synovial cytology indicated improvement. The filly was discharged with a prescription of minocycline for 30 days. Despite initial improvement, recurrent lameness with bilateral tarsocrural effusion without radiographic abnormalities occurred 8 months later. Repeated synovial cytology showed macrophagic synovitis without an eosinophilic component. The filly was discharged with instructions to complete a 14-day course of minocycline, resulting in complete recovery. Based on the serology results and response to therapy, this report describes a possible naturally occurring eosinophilic synovitis with likely involvement of <em>B. burgdorferi</em>, a condition previously unreported in horses.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"150 ","pages":"Article 105595"},"PeriodicalIF":1.3,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143937340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of intra-arterial cisplatin on dorsal hoof wall tissue of isolated perfused equine limbs","authors":"B. Reinthaler ,&nbsp;S. Gabner ,&nbsp;V. Apprich ,&nbsp;M. Jehle ,&nbsp;T. Licka","doi":"10.1016/j.jevs.2025.105598","DOIUrl":"10.1016/j.jevs.2025.105598","url":null,"abstract":"<div><div>Equine hoof canker is a chronic proliferative condition of the hoof tissues that is often time-consuming and frustrating to treat. After surgical debridement, topical application of cisplatin (cis-Diamindichlorplatin II) has been reported, requiring repeatedly handling this hazardous substance during bandage changes. Alternatively, intraarterial application of cisplatin could be used, similar to the treatment of some human neoplastic diseases. As the side effects of such a treatment are currently unknown, evaluation of associated risks is necessary before treating live horses. Thus, forelimbs of thirteen horses underwent an eight-hour perfusion protocol; nine limbs received a 20-minute intraarterial cisplatin infusion (14 mg/600 ml autologous blood-plasma perfusate). Post-treatment, dorsal hoof wall samples were subjected to histological (hematoxylin and eosin) and immunohistochemical (laminin, Ki-67) analysis. Comparisons were carried out using a linear mixed model analysis to investigate the effect of cisplatin. Appearance of primary and secondary epidermal lamellae was not significantly affected by the cisplatin treatment. Notable basal membrane damage was evidenced by significantly weaker laminin staining intensity in the limbs of the cisplatin group than in the control group (<em>p</em> = 0.005). Cisplatin samples showed 54 % weak, 37 % moderate and 9 % strong staining intensities, and control samples showed 12 % weak, 53 % moderate and 35 % strong staining intensities. Median numbers of Ki-67 positive basal cells in the primary epidermal lamellae were not affected by cisplatin. Specifically, even short-term cisplatin exposure significantly compromises the basal membrane of the dorsal hoof wall creating a considerable risk of laminitis.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"150 ","pages":"Article 105598"},"PeriodicalIF":1.3,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143937338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morel-Lavallée lesion on the craniomedial aspect of the stifle in a horse: diagnosis, surgical management and outcome","authors":"F. Cantatore ,&nbsp;M. Marcatili ,&nbsp;A. Giacchi ,&nbsp;R. Stephenson ,&nbsp;J. Withers","doi":"10.1016/j.jevs.2025.105599","DOIUrl":"10.1016/j.jevs.2025.105599","url":null,"abstract":"<div><div>Morel-Lavallée lesions (MLLs) are post-traumatic, closed, degloving injuries observed in humans and cats. Morel-Lavallée lesions have never been reported in horses. An 8-year-old Warmblood gelding used for dressage presented with a large swelling on the craniomedial aspect of the stifle that did not respond to conservative treatment. Ultrasonography revealed a large anechogenic fluid-filled cavity with a well-defined capsule. Standing endoscopic examination revealed separation between the deep crural fascia, <em>vastus medialis</em> muscle and skin. Cytology of the fluid collected demonstrated a lymphocyte-rich transudate. Complete surgical excision of the capsule was performed under general anaesthesia. Histopathology of the capsule identified dense fibrovascular tissue lining with an outer thin zone of adipose connective tissue consistent with a MLL. The horse returned to its former athletic level after nine months. The cosmetic outcome was excellent. Chronic MLLs in horses can be successfully treated by complete surgical excision of the capsule with excellent outcome.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"150 ","pages":"Article 105599"},"PeriodicalIF":1.3,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143943395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The global prevalence of Giardia infection in horses: A systematic review and meta-analysis","authors":"Azadeh Mizani ,&nbsp;Parastoo Taherkhani ,&nbsp;Elham Kia Lashaki ,&nbsp;Seyed Abdollah Hosseini ,&nbsp;Bahareh Basirpour ,&nbsp;Samira Dodangeh","doi":"10.1016/j.jevs.2025.105596","DOIUrl":"10.1016/j.jevs.2025.105596","url":null,"abstract":"<div><div><em>Giardia duodenalis</em> as a common zoonotic parasite is a public health problem infecting humans and a wide range of animals, including horses. This systematic review and meta-analysis was conducted to estimate the global pooled prevalence of <em>Giardia</em> infection in horses. Literature searches were conducted using databases including Scopus, ScienceDirect, PubMed, Web of Science and ProQuest to December 2023. A random-effect model was performed to calculate the pooled prevalence and corresponding 95% confidence interval (CI) according to the degree of heterogeneity in the included studies. Of 2661 articles, approximately 27 articles were eligible for inclusion in the meta-analysis. The pooled prevalence of giardiasis in horses using the random effect method was 8.93% (95% CI = 5.98% to 12.42%). There were significant differences between the giardiasis prevalence in different continent, countries and ages of horses. The highest and lowest prevalence of giardiasis was found in Europe (12.24%) and Africa (0 %), respectively. The prevalence of <em>Giardia</em> was significantly higher in horses &lt;3 years of ages. Based on the diagnostic method, the highest and lowest incidence of horse <em>Giardia</em> infection was detected by immunological assays (9.24%) and molecular methods (7.87%), respectively. The result of our study showed that assemblage B is the most common genotype in horses followed by assemblage A and E. Due to the widespread use of horses on farms or for recreational riding, data on the source of infection, prevalence, transmission mechanisms, and genotype are crucial for the establishment of control and prevention strategies.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"150 ","pages":"Article 105596"},"PeriodicalIF":1.3,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143943394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How nutrigenomics impacts equine health - A case study of vitamin E","authors":"C.J. Finno","doi":"10.1016/j.jevs.2025.105421","DOIUrl":"10.1016/j.jevs.2025.105421","url":null,"abstract":"<div><div>Nutrigenomics defines the interaction between the nutrients in our food and the genes in our body. Examples from human medicine of diseases and associated genes include lactose intolerance (genetic variants in <em>LCT lactase</em>), hypercholesteremia (<em>low density lipoprotein receptor, LDLR</em>) and caffeine sensitivity (<em>adenosine A2A receptor, ADORA2A</em>). In horses, examples include Hyperkalemic Periodic Paralysis (HYPP), where clinical signs of disease are managed through maintaining a diet low in potassium and Polysaccharide Storage Myopathy Type 1 (PSSM1), where low starch and high fat diets are recommended to prevent episodes of rhabdomyolysis. Personalized nutrition tailors nutrition advice for an individual based on their genetic makeup. In humans and in horses, there is a wide range of individual response to vitamin E supplementation. Some horses obtain very high serum vitamin E concentrations with minimal intake, whereas others require high doses of supplementation to remain in the normal range. In humans, the efficiency of vitamin E absorption is widely variable and is affected by dietary factors, such as food matrix, and genetic polymorphisms in genes related to vitamin E intake, distribution and metabolism. In horses, the efficiency of vitamin E absorption is also related to diet; however, genetic variation has not been yet evaluated. With over 200 genetic variants identified in and surrounding vitamin E candidate genes in horses, future genetic profiling of vitamin E response in horses should be performed.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105421"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143692244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of maternal body condition on maternal and foal metabolism","authors":"C.S. Summers,&nbsp;N.M. Barnello,&nbsp;S.P. Voggu,&nbsp;K.E. Govoni,&nbsp;S.A. Zinn,&nbsp;S.A. Reed","doi":"10.1016/j.jevs.2025.105472","DOIUrl":"10.1016/j.jevs.2025.105472","url":null,"abstract":"<div><div>The maternal environment during gestation can influence foal metabolism. The objective of this study was to investigate the impact of moderate differences in maternal body condition during late gestation on mare and foal metabolism. We hypothesized that differences in maternal body condition would alter dam glucose metabolism and leptin concentrations, and foal leptin concentrations during the early postpartum period. Light breed mares (n = 6) were divided into moderately obese (MO; n = 3) or lean (LN; n = 3) groups based on body condition score (BCS) and cresty neck score (CNS) at 315 (±0.5) days of gestation. Mares were fasted overnight and underwent intravenous (i.v.) glucose tolerance tests at 315 (±0.45) days gestation, and 60 (±0.6) and 119 (±1.3) days postpartum (pp). Mares were administered dextrose i.v. (0.3 g/kg BW) followed by an i.v. insulin infusion (0.3 mU/kg BW) 20 min later. Blood samples were collected from a jugular vein at −30, −15, 0, 2, 5, 10, 15, 20, 25, 30, 45, 60, and 120 min relative to dextrose infusion. Glucose and insulin concentrations were determined by ELISA. Circulating leptin concentrations were analyzed in mares at parturition, and 59 (±0.6) and 118 (±1.3) days pp, and in foals on d 1, 7, 14, 28, 59, and 118 of age by RIA. Differences between groups were tested using a <em>t</em>-test with significance at <em>P</em> ≤ 0.05 and a tendency at 0.05 &lt; <em>P</em> ≤ 0.10. The MO group had greater BCS (6.1 ± 0.3; <em>P</em> = 0.01) and CNS (2.7 ± 0.2; <em>P</em> = 0.01) than LN mares (BCS: 4.3 ± 0.3; CNS: 1.3 ± 0.2). Moderately obese mares tended to have 8% greater glucose area under the curve (AUC) after dextrose (<em>P</em> = 0.10) and 9% greater glucose AUC after insulin infusion (<em>P</em> = 0.10) than LN mares at 315 d of gestation. At d 60 pp, LN mares tended to have 69% greater insulin AUC after dextrose (<em>P</em> = 0.10) and 70% greater insulin AUC after insulin (<em>P</em> = 0.10) infusion than MO mares. At d 119 pp, LN mares had 23% greater insulin AUC before dextrose infusion (<em>P</em> = 0.04) than MO mares. Moderately obese mares tended to have 87% greater leptin concentrations at parturition (13.2 ± 2.8 ng/mL; <em>P</em> = 0.06) and 80% greater leptin concentrations on d 118 pp (7.7 ± 1.4 ng/mL; <em>P</em> = 0.06) than LN mares (parturition: 5.2 ng/mL ± 1.1; d 118: 3.3 ng/mL ± 1.0). There were no observed differences in leptin concentrations among foals born to LN or MO mares. Differences in maternal glucose metabolism and leptin concentrations suggest metabolic differences among lean and moderately obese mares. However, moderate changes in maternal body condition do not appear to affect foal leptin concentrations in the early postpartum period.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105472"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physiological and behavioral responses of horses to high wet bulb globe temperature and shade access","authors":"C. Suber ,&nbsp;S. Wright ,&nbsp;M.M. Friend ,&nbsp;S.M. Hall ,&nbsp;L. Hanna ,&nbsp;D.N. Smarsh ,&nbsp;W.B. Staniar","doi":"10.1016/j.jevs.2025.105479","DOIUrl":"10.1016/j.jevs.2025.105479","url":null,"abstract":"<div><div>Agricultural animal care guidelines state that shade should be available when temperatures reach 30°C. The recommendation does not account for variables like humidity, solar radiation, or duration of exposure, which influence thermal load. The objective was to determine whether access to shade or wet bulb globe temperature (WBGT) influence a horse's physiological responses and behavior. Twelve Quarter Horses (13 ± 6 yr, 571 ± 59 kg, 6.0 ± 0.8 BCS) were used to investigate the hypothesis that WBGT or access to shade would affect salivary cortisol (SC), rectal temperature (RT), heart rate (HR), and daily distance traveled. Horses were divided into 3 groups of 4 horses and rotated daily among three 1.5-acre paddocks for 12 d, resulting in 4 repeated rotations. Paddock 1 had 961 ft² of man-made shade available, with food and water only accessible in sun. Paddock 2 had no shade available. In paddock 3, man-made shade was available (961 ft²), with food and water located in shade. Horses were in paddocks 24 h/d and 7 d/wk. The WBGT was recorded in sun and shade. Daily sampling consisted of saliva for SC, collected at 1600 h; RT at 0800, 1200, and 1600 h; continuous HR from 2 horses per paddock from 0800 to 1600 h; and continuous GPS tracking from 0800 to 1600 h. The SC was measured using an enzyme immunoassay (Salimetrics, Carlsbad, CA). Daily distance traveled was approximated as the cumulative distances recorded for all GPS intervals from 08:00–16:00. The GPS data were used to create location heat maps with GIS software. Data were analyzed with a repeated measures mixed ANOVA including fixed effects of paddock, WBGT, and their interaction. When applicable, the repeated measure was time of day nested within day nested within 1 of 4 repeated rotations. Horse nested within group was the random effect, with group as the experimental unit. Differences were significant at <em>P</em> &lt; 0.05. Data are presented as a ranges and medians. The WBGT between 0800 and 1600 h was higher in sun (18–34, 28°C) than shade (16–31, 26°C). Paddock had no detectable effect on SC, RT, or HR. The WBGT had no effect on SC or HR but resulted in a 0.03°C rise in RT for each 1°C increase in WBGT. Horses in paddocks with food and water outside of shade traveled 0.3 km more daily than those with no shade, whereas horses with food and water under shade showed intermediate travel distances. GPS heat maps suggest the increased movement in paddock 1 is driven by horses seeking both shade and access to food and water. The results of this study indicate that horses demonstrate some motivational behavior to use shade in high WBGT conditions. Guidelines should allow for a more nuanced approach to shade provision.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105479"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}