Journal of Equine Veterinary Science最新文献

{"title":"Characterizing the effects of management practices on inflammatory markers in a population of horses in Pennsylvania","authors":"S.M. Hall,&nbsp;M.M. Friend,&nbsp;D.N. Smarsh,&nbsp;W.B. Staniar","doi":"10.1016/j.jevs.2025.105465","DOIUrl":"10.1016/j.jevs.2025.105465","url":null,"abstract":"<div><div>Horses are valued for athletic production and companionship. This leads to management that emphasizes exercise training, high energy diets, and longevity. A potential negative outcome of these management practices is increased risk of noninfectious degenerative diseases associated with inflammation. The objective of this observational study was to characterize the effects of management practices on inflammatory markers in a population of relatively healthy horses in Pennsylvania. Blood samples, heart rate, rectal temperature (RT), and body condition score were collected from 144 horses from 14 different barns across the state of Pennsylvania. Concurrently, owners or trainers completed a 65-question survey detailing the horses’ dietary, exercise, and health management. Horses (1–40 yr, mean 14 yr) included mares (n = 77), geldings (n = 61), and stallions (n = 6) of various breeds. The majority (91%) of horses were fed before sampling. Blood was drawn between 07:00 and 15:30, centrifuged, and plasma separated and stored at −80°C. Serum amyloid A (SAA), C-reactive protein (CRP), and haptoglobin (HP) were quantified with ELISAs and a peroxidase assay. Results of the assays and data from the survey were analyzed with significance set at <em>P</em> &lt; 0.05 and trends at <em>P</em> &lt; 0.1. Shapiro-Wilk tests identified that most of the data were not normally distributed. Kruskal-Wallis tests were performed, followed by Dunn's tests to evaluate differences. Data are presented as median and interquartile range. Horses fed hay had lower CRP (8.9, 10.8 mg/L) than those that were not (12.1, 21.8 mg/L). Horses fed a fiber replacer had both lower CRP and RT (7.1, 7.5 mg/L; 37.3, 0.9°C) than those that were not (11.5, 16.9 mg/L; 37.6, 0.7°C). Horses fed cereal grains had lower HP (2510, 2530 mg/L) than those that were not (2886, 1976 mg/L). There was a trend (<em>P</em> = 0.071) for HP to be lower (2429, 2799 mg/L) in exercised horses than those that were not (2808, 1817 mg/L). The SAA tended (<em>P</em> = 0.054) to increase as the NRC designated exercise category increased from light (0.73, 0.31 mg/L, n = 16) to moderate (0.92, 0.64 mg/L, n = 25) to heavy (1.56, 0.59 mg/L, n = 5). This observational study highlights how differences in dietary and exercise practices can influence acute phase proteins and physiological measures that are key indicators of chronic subclinical inflammation. These findings offer a foundation for future hypothesis-driven research to explore how specific management strategies impact inflammatory markers and the risk of noninfectious degenerative diseases.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105465"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948154","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":"Effects of dietary aid on lipid peroxidation and antioxidant capacity after exercise in young horses","authors":"A.S. Reiter ,&nbsp;J.L. Leatherwood ,&nbsp;T.A. Brooks ,&nbsp;H.D. Lykins ,&nbsp;A.M. Trauner ,&nbsp;C.E. Arnold ,&nbsp;K.G. Glass ,&nbsp;C.R. Gualandri ,&nbsp;L.R. Pavel ,&nbsp;S.C. Nelson ,&nbsp;B.L. Paris ,&nbsp;A. Pritchard ,&nbsp;H.S. Spooner ,&nbsp;R.E. Martinez ,&nbsp;A.N. Bradbery","doi":"10.1016/j.jevs.2025.105429","DOIUrl":"10.1016/j.jevs.2025.105429","url":null,"abstract":"<div><div>During training, young horses experience intense exercise that can disrupt the gastrointestinal environment, contributing to increased oxidative damage and decreased antioxidant capacity. Supplementing dietary aids may support systemic oxidative balance following intense exercise. Therefore, the objective of this study was to determine the effect of a dietary aid on lipid peroxidation and total antioxidant capacity (TAC) following a submaximal exercise test (SET). It was hypothesized the dietary aid would decrease lipid peroxidation and increase TAC. To test this hypothesis, twenty 2-year-old stock-type horses from an established herd with no history of forced exercise were individually housed and allowed a 14-d acclimation period. Horses, balanced by body weight (BW; 417 ± 35 kg) and sex, were offered 0.75% BW concentrate/d containing no dietary aids (CON; n = 10) or a blend of pre-, pro-, and post-biotics, marine calcite, and organic trace minerals (Digestive Shield; DS; n = 10). On d 0, horses began supplementation and a progressive exercise program, increasing intensity every 7 d. On d 30, horses completed a 1 h SET. Blood samples were collected via jugular venipuncture on d 0, before supplementation, and before (PRE), immediately after (POST), 0.5, and 1 h after SET to evaluate circulating malondialdehyde (MDA), a marker of lipid peroxidation, and TAC in Trolox Equivalent (TE). Data were analyzed using PROC MIXED in SAS with fixed effects of dietary aid, time, sex, and their interactions. The effect of sex was nonsignificant (<em>P</em> ≥ 0.33) and removed to conserve degrees of freedom. Significance was declared when <em>P</em> ≤ 0.05 and a trend when 0.05 &lt; <em>P</em> ≤ 0.10. On d 0, no differences were observed between CON and DS in MDA or TAC (<em>P</em> ≥ 0.17). Overall, circulating MDA was greater in CON (3.14 ± 0.15 µM) than in DS horses (2.68 ± 0.14 µM; <em>P</em> = 0.03). At PRE (3.47 ± 0.23 µM), MDA tended to be greater than 0.5 h (2.83 ± 0.23 µM; <em>P</em> = 0.06) and greater than 1 h (2.75 ± 0.23 µM; <em>P</em> = 0.03). At POST (3.01 ± 0.23 µM), circulating MDA did not differ from PRE, 0.5 h, or 1 h (<em>P</em> ≥ 0.30). Supplementing DS did not affect circulating TAC during the SET (CON: 0.90 ± 0.08 TE; DS: 0.87 ± 0.08 TE; <em>P</em> = 0.61). The time point relative to SET did not impact circulating TAC (PRE: 0.90 ± 0.10 TE; POST: 0.88 ± 0.10 TE; 0.5 h: 0.95 ± 0.09 TE; 1 h: 0.81 ± 0.09 TE; <em>P</em> = 0.66). These data indicate that supplementing DS may decrease lipid peroxidation but does not impact TAC after submaximal exercise in young horses. Further research should evaluate the impact of DS on DNA and protein oxidation in young exercising horses.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105429"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947748","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":"Feed protein partitioning impacts horse fecal nitrogen profiles: A pilot study","authors":"R.W. Springer ,&nbsp;M.R. Plowman ,&nbsp;H.M. Saur ,&nbsp;G.A. Wirtz ,&nbsp;N.M. Cherry ,&nbsp;J.P. Muir ,&nbsp;W.F. Owsley ,&nbsp;T.N. Jones","doi":"10.1016/j.jevs.2025.105430","DOIUrl":"10.1016/j.jevs.2025.105430","url":null,"abstract":"<div><div>Horses are often fed diets with excess crude protein (CP). Current research is evaluating the impact of CP partitioning in feedstuffs and its implications for digestion and subsequent fecal and urinary excretion in the horse. However, work is lacking in how CP partitioning in the diet affects nitrogen profiles in equine feces. Feces are often used as fertilizer for pastures; therefore, the nitrogen profile can affect nitrogen availability to plants. Thus, our pilot study objective was to determine the impact of daily CP, foregut available protein (NDSCP: CP-NDICP), foregut-unavailable protein (NDICP), hindgut-available protein (ADSCP: NDICP-ADICP), and unavailable protein (ADICP) intakes on equine fecal nitrogen profiles. In phase 1, 3 Quarter Horse geldings (n = 3; 579.5 <em>±</em> 30.4 kg BW) were fed 15 g DM/kg BW/d of coastal Bermudagrass hay with 0.5 kg/d of a commercial concentrate for 14 d. After a 7-d transition period, diets consisted of 7.5 g/kg DM/BW/d of coastal Bermudagrass hay and 7.5 g/kg DM/BW/d of alfalfa hay with 0.5 kg of a commercial concentrate for 14 d (phase 2). The forage portions in phases 1 and 2 consisted of 134 and 161 g CP/kg DM diet; 88 and 121 g NDSCP/kg diet; 46 and 40 g NDICP/kg diet; 40 and 30 g ADSCP/kg diet; 6 and 10 g ADICP/kg diet, respectively. Fresh feces were collected once each phase (d 14) via rectal grab, then analyzed by a commercial laboratory (Dairy One, Ithaca, NY, USA). Dietary intakes (hay + concentrate) were collected daily and BW on d 0, 7, and 14 of each phase. Total dietary protein fraction intakes were expressed on a g/d- and g/kg BW/d basis while fecal results were expressed as fecal-nitrogen (fecal-N), fecal-ammonia (fecal-NH₃), fecal organic-nitrogen (organic-N), and fecal carbon-to-nitrogen ratio (C:N) on a g DM/kg BW- and g/DM feces-basis. Data were analyzed within the R Statistical Program (v4.4.0) using a Pearson correlation with significance set at <em>P</em> ≤ 0.05 and trends at <em>P</em> ≤ 0.15. Increases in both CP (g/kg BW; r = −0.80; <em>P</em> = 0.06) and ADICP (g/d; r = −0.78; <em>P</em> = 0.07) intakes tended to decrease fecal C:N. Fecal-N tended to increase with daily CP (g/d; r = 0.75; <em>P</em> = 0.09) and NDSCP (g/d; r = 0.69; <em>P</em> = 0.13) intakes. Fecal-NH₃ tended to decrease with increasing NDICP intakes (g/d; r = −0.83; <em>P</em> = 0.08) while organic-N tended to increase with daily CP intakes (g/d; r = 0.73; <em>P</em> = 0.10). Increases in dietary CP increase daily excretion of nitrogen; however, shifting CP availability from the small intestine to the hindgut may decrease the fecal C:N through increased fecal-NH₃. While only a pilot study, the results showed dietary protein fractionation may affect equine fecal nitrogen profile and merit further examination.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105430"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947749","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":"Duration and efficacy of a single pulsed electromagnetic field (PEMF) therapy on lameness associated with osteoarthritis of the tarsus","authors":"I. Wilson,&nbsp;K. Kiger,&nbsp;S. Reynolds,&nbsp;M. Justice,&nbsp;C.L. Kapadia,&nbsp;R.A. Crook,&nbsp;C.E. Fedorka","doi":"10.1016/j.jevs.2025.105450","DOIUrl":"10.1016/j.jevs.2025.105450","url":null,"abstract":"<div><div>Pulsed electromagnetic field (PEMF) therapy is utilized in sports medicine due to its perceived impact on bone formation, tissue repair, and anti-inflammatory properties. However, there is limited research on the efficacy and duration of PEMF treatments in horses. This study evaluates the impact of PEMF on horses with lameness associated with osteoarthritis of the tarsus joint. We hypothesized that PEMF would reduce lameness, influenced by timing of therapy before lameness assessment. Six Thoroughbred mares with a history of tarsal osteoarthritis participated in a randomized switch-back design. After establishing baseline measurements, each mare received a 30-min PEMF treatment at 5 Hz, via the small butterfly coil directly to the tarsus, with 7 d between treatments. TxHour was administered one hour before flexion, TxDay was administered one day before, and TxWeek was administered one week before flexion. Lameness was assessed subjectively with response to flexion measured on a 4-point scale, and measures performed by a practitioner blinded to treatment. Statistics were performed utilizing SAS 9.4, and all data were assessed for normality and equal variances before analyses. Following, the impact of duration of PEMF treatment on flexion scores was assessed utilizing a general linear model, with post hoc analysis performed utilizing Tukey LSD. Significance was set to <em>P</em> ≤ 0.05, with trends noted between <em>P</em> &gt; 0.05 and <em>P</em> &lt; 0.1. There was a trend toward an overall impact of PEMF treatment on flexion scores, regardless of time to flexion (<em>P</em> = 0.09). When spliced for time, significance was noted in the TxHour group (<em>P</em> = 0.03) but not in the TxDay (<em>P</em> = 0.17) or TxWeek groups (<em>P</em> = 0.18). In conclusion, PEMF therapy decreased lameness associated with osteoarthritis of the tarsus, but this was only noted when PEMF was performed immediately before flexion test. Future research is needed to assess the efficacy of varying PEMF protocols (power, duration, frequency) to create standardized protocol guidelines.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105450"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948337","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 palmar digital perineural analgesia (as a model for “nerving”) on forelimb loading over various surfaces at the walk and trot: A pilot study","authors":"S. Zimmerman-Cameron ,&nbsp;A. Colbath ,&nbsp;M. Caruso III ,&nbsp;M. Leath ,&nbsp;A. Logan","doi":"10.1016/j.jevs.2025.105452","DOIUrl":"10.1016/j.jevs.2025.105452","url":null,"abstract":"<div><div>Navicular syndrome is one of the most common causes of lameness in horses characterized by inflammation and degeneration of the navicular bone with or without soft tissue involvement. Palmar digital neurectomy or “nerving” removes the sensation to the heel region of the hoof and allows horses with navicular syndrome to still compete without pain. This method does not heal the disease but may mask symptoms. Analgesia or “blocking” of the palmar digital nerves results in temporary loss of sensation. The purpose of this pilot study was to examine the effect of loss of sensation in the heel (as a result of blocking) on the forelimb area and force while tracking on soft and hard ground at the walk and trot. It was hypothesized that soft ground would result in greater normal force and pressure distribution of the hoof and analgesia of the palmar digital nerves would result in greater loading on all surfaces at the walk and trot. Three mature stock-type horses determined to be without lameness were fitted to Tekscan Hoof Sensors via glue-on shoes on the front hooves. Each horse was randomly assigned the order for each test which included walking and trotting on a hard (rubber alleyway) and soft surface (arena clay). Horses completed the same exercise sessions pre- and post-nerve blocking examining hoof normal force, loaded area, and stride duration. After the pre-blocking runs, horses completed the same tests but underwent palmar digital analgesia or “blocking” by a veterinarian. Analysis was performed in SAS 9.4 with a GLIMMIX procedure: fixed effects of gait, run, ground, step, block, and leg, with interactions. Interaction of ground and blocking status was significant for area (<em>P</em> &lt; 0.0001), with post-blocking having greater loaded area than pre-blocking while tracking on hard ground (<em>P</em> = 0.008), but no difference between pre- and post-blocking on soft ground (<em>P</em> = 0.94). The same interaction was found significant for force (ground × block <em>P</em> &lt; 0.0001), with force while tracking over hard ground being greater post-blocking than pre-blocking (<em>P</em> = 0.008), but not different while tracking over soft ground (<em>P</em> = 0.20). Interaction of gait and blocking status was not significant for area (<em>P</em> = 0.41) or force (<em>P</em> = 0.10). Stride duration was greater pre-blocking than post-blocking (<em>P</em> = 0.0017). Findings from this pilot study show that temporary blocking impacts forelimb loading characteristics and that ground may be an important factor in tracking for horses with removed sensation to the forelimb heel and provides support for further exploration into the long-term effects of nerving.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105452"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948339","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":"Effects of digestive aid on systemic stress and inflammation in response to exercise in young horses","authors":"H.D. Lykins ,&nbsp;J.L. Leatherwood ,&nbsp;A.S. Reiter ,&nbsp;T.A. Brooks ,&nbsp;A.M. Trauner ,&nbsp;C.E. Arnold ,&nbsp;K.G. Glass ,&nbsp;C.R. Gualandri ,&nbsp;L.R. Pavel ,&nbsp;S.C. Nelson ,&nbsp;B.L. Paris ,&nbsp;A. Pritchard ,&nbsp;H.S. Spooner ,&nbsp;R.E. Martinez ,&nbsp;A.N. Bradbery","doi":"10.1016/j.jevs.2025.105454","DOIUrl":"10.1016/j.jevs.2025.105454","url":null,"abstract":"<div><div>Repeated bouts of intense exercise can disrupt the gastrointestinal environment and initiate stress and immune responses, negatively impacting the performance of young horses in training. Dietary aids supporting the microbiome, gastric buffering, and trace mineral fortification may modulate the stress and inflammatory response associated with intense exercise. This study aimed to determine the effect of a dietary aid on the cortisol and inflammatory cytokine response to a submaximal exercise test (SET), hypothesizing that dietary aids would decrease cortisol and modulate the inflammatory cytokine response to a SET. Twenty 2-year-old stock-type horses, balanced by body weight (BW; 417 ± 35 kg) and sex, were offered 0.75% BW concentrate/d containing no dietary aids (CON; n = 10) or Digestive Shield, a blend of pre-, pro-, and postbiotics, marine calcite, and organic trace minerals (DS; n = 10). On d 0, horses began supplementation and a progressive exercise program, and on d 30, horses completed a 1 h SET. Blood samples were collected via jugular venipuncture before (PRE), immediately after (POST), and 1, 2, 4, 8, and 12 h after SET to evaluate circulating cortisol, interleukin (IL-) 6, 8, 18, 10, and tumor necrosis factor-a (TNF-α). Data were analyzed using PROC MIXED in SAS, where non-normal data were log-transformed. Fixed effects included dietary aid, time, sex, and their interactions; however, if nonsignificant, sex was removed to conserve degrees of freedom. Significance was declared when <em>P</em> ≤ 0.05 and a trend when 0.05 &lt; <em>P</em> ≤ 0.10. Cortisol POST SET was 48% greater than PRE (<em>P</em> &lt; 0.01) and remained elevated until 2 h after SET (<em>P</em> &lt; 0.05). Dietary aid and sex did not influence cortisol (<em>P</em> &gt; 0.10). Interleukin-6 tended to be 26% greater in CON compared with DS horses (<em>P</em> &lt; 0.10), and mares had 61% greater IL-6 than geldings (<em>P</em> &lt; 0.01). Interleukin-8 was 13% less in CON compared with DS horses (<em>P</em> &lt; 0.01). Interleukin-18 was 29% less in CON horses compared with DS (<em>P</em> &lt; 0.01), and mares had 30% greater IL-18 than geldings (<em>P</em> &lt; 0.01). The CON mares had the greatest IL-10, while DS mares had 35% greater IL-10 than CON geldings (<em>P</em> &lt; 0.01), but there was no difference between DS mares and geldings (<em>P</em> &gt; 0.10). Tumor necrosis factor-α was 34% greater in CON than DS horses (<em>P</em> &lt; 0.05). Sex did not influence TNF-α (<em>P</em> &gt; 0.10). Time after SET did not affect inflammatory mediators (<em>P</em> &gt; 0.10). These data indicate that dietary aids do not impact postexercise cortisol response but reduce inflammatory mediators IL-6 and TNF-α, thus modulating the inflammatory cytokine response in young horses.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105454"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948341","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":"Endometrial inflammatory profile of pituitary pars intermedia dysfunction (PPID)","authors":"J. Howard,&nbsp;I. Hamner,&nbsp;R.A. Crook,&nbsp;G. Unger,&nbsp;S.J. Coleman,&nbsp;P.M. McCue,&nbsp;C.E. Fedorka","doi":"10.1016/j.jevs.2025.105503","DOIUrl":"10.1016/j.jevs.2025.105503","url":null,"abstract":"<div><div>Pituitary pars intermedia dysfunction (PPID) is an endocrine disorder associated with elevated adrenocorticotropin hormone (ACTH) and cortisol. Animals experiencing PPID have been found to have elevated systemic inflammation, and specifically an upregulation of the proinflammatory cytokine interleukin-8 (IL-8). It is unknown if this inflammation is present within the reproductive tract. Inflammation of the endometrium, or endometritis, is the leading cause of subfertility in the broodmare. Therefore, the objective of this study is to evaluate the impact of PPID on the endometrium of the mare. We hypothesize that elevated ACTH will lead to an increase in IL-8 expression in the endometrium, therefore predisposing mares to endometritis. To do so, 11 mares were screened for PPID using a thyrotropin-releasing hormone (TRH) stimulation test in late summer. In brief, ACTH concentrations were measured before and 1 h after stimulation with 1.0 mg TRH. Of these, 7 mares were found to be PPID positive (n = 7; ACTH &gt;110 pg/mL), and 4 were found to be PPID negative (n = 4; ACTH &lt;30 pg/mL). Ultrasound was routinely performed transrectally to determine stage of estrous cycle. When in diestrus (presence of a corpus luteum; uterine tone; P4 &gt;4 ng/mL), an endometrial biopsy was obtained from all mares for qPCR analysis of select inflammatory cytokines. Statistics were performed on SAS 9.4, and data were assessed for normality and equal variances utilizing a Bartlett's and Shapiro–Wilk test. The impact of PPID on cytokine expression was evaluated using an unequal variances <em>t</em>-test. Correlation between ACTH and cytokine expression was assessed using a Pearson correlation. The relationship between cytokine expression and systemic ACTH concentration noted post-stimulation was assessed using a linear regression. Significance was set at <em>P</em> &lt; 0.05. Of the cytokines evaluated, only IL-8 was found to increase in expression in the PPID population (<em>P</em> = 0.02). There was no effect of PPID on the expression of IL-1β (<em>P</em> = 0.27), IL-6 (<em>P</em> = 0.19), or IFNγ (<em>P</em> = 0.14). There was a positive correlation between ACTH post-TRH stimulation and the endometrial expression of IL-8 (<em>P</em> &lt; 0.001; R² = 0.80). A weak positive correlation was also noted between ACTH and endometrial expression of IL-6 (<em>P</em> = 0.04; R² = 0.41) and IFNγ (<em>P</em> &lt; 0.01; R² = 0.63). In conclusion, the systemic inflammation noted in the PPID animal is also observed within the endometrium. The increase in endometrial IL-8 may be associated with reduced fertility in mares with PPID.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105503"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948471","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":"Stereotypic behaviors and physiological indicators of stress occur in horses with restricted durations of turnout","authors":"E. Rodgers,&nbsp;D. Yates,&nbsp;R. Woiwode,&nbsp;B. Parrish,&nbsp;L. Luck","doi":"10.1016/j.jevs.2025.105481","DOIUrl":"10.1016/j.jevs.2025.105481","url":null,"abstract":"<div><div>The confinement of horses to stalls with limited or no turnout time restricts their natural roaming behaviors, which potentially increases stress and behavioral stereotypies. This study investigated the impact of turnout duration on behavioral and physiological stress indicators in healthy horses. Adult (n = 11) horses were enrolled in a 3-period × 3-treatment (0, 15, and 60 min turnout/day) Latin square design, including three 12-d experimental periods over 6 wk. Horses were acclimated to turnout (80 ft × 210 ft indoor arena) and stalls before data collection on d 1. Experienced handlers managed turnout of horses and had no issues with catching or releasing them. Behavioral data were collected by video and assessed through ethograms. Physiological measures included heart rate variability (HRV) and differential complete blood counts. Statistical analyses were conducted by ANOVA using repeated measures and multiple comparisons <em>t</em>-tests with Fisher's LSD. Analyzing turnout treatments (15 and 60 min turnout per day), heart rate variability measurements were decreased (<em>P</em> &lt; 0.05), including RR-interval, RMSSD, and pNN50 in the 15-min treatment compared with 60-min treatment, indicating a state of stress. Assessing stalled data (0, 15, and 60 min turnout), LF/HF power (a measure of HRV) was lowest (<em>P</em> &lt; 0.01) with the 60-min turnout compared with 0- and 15-min turnouts, indicating a relaxed state. Blood cell analyses uncovered an increase (<em>P</em> = 0.04) during 15-min turnout, indicating an acute stress response. This result is consistent with a trend (<em>P</em> = 0.06) in circulating leukocytes, increasing during the 15-min turnout compared with 0- and 60-min turnouts. Behavioral assessments in stalls showed that when horses received a 60-min turnout, they tended to exhibit less (<em>P</em> = 0.10) stalled locomotion than when receiving a 15-min turnout. Stereotypic and aggressive behaviors were variable but did not differ among turnout times. A limitation of this study was an inability to analyze the complete behavioral dataset (video footage). These findings demonstrate that restricted turnout durations influence physiological and behavioral stress indicators in horses. Specifically, 15 min of daily turnout appeared to be associated with unique stress responses. The longer turnout duration of 60 min appeared to mitigate this physiological stress, which highlights the importance of adequate daily turnout time in horse management practices.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105481"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948516","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 ostarine on liver function in adult horses","authors":"K. Kaldon ,&nbsp;A.C. Herbst ,&nbsp;S.H. White-Springer ,&nbsp;K. Malinowski ,&nbsp;K.H. McKeever","doi":"10.1016/j.jevs.2025.105446","DOIUrl":"10.1016/j.jevs.2025.105446","url":null,"abstract":"<div><div>Ostarine is a selective androgen receptor modulator which has been shown to increase muscle mass in humans while causing minimal androgenic side effects. Although some studies indicate an acceptable safety profile of ostarine, there have been multiple reports of liver damage in people using the drug. Ostarine has also been detected in some racehorses, yet it is currently unclear if ostarine adversely affects horse health, and especially liver function. The objective of this study was therefore to determine if ostarine affects liver function in adult horses, and it was hypothesized that ostarine would alter indicators of liver health and function. Blood was collected from 9 Standardbreds (ages: mean = 17.22 ± 2.5 years; range = 13–21 years) before treatment (baseline), during a 4-week ostarine treatment period (blood collections in treatment wk 2, 3, 4), and once right after conclusion of the treatment period. The duration of the ostarine treatment period was informed by an ostarine rodent study. Four horses were in the treatment group and received intravenous ostarine injections 4 times a week (on nonconsecutive days), while 5 horses were in the control group and received a vehicle control (ethanol) intravenously on treatment days. The liver enzymes aspartate aminotransferase (AST), gamma-glutamyl-transferase (GGT), and glutamate-dehydrogenase (GLDH) were quantified in the horse's blood samples. Data were analyzed by mixed-model ANOVA. For AST, GLDH, and GGT, there was no significant treatment effect (<em>P</em> = 0.37, <em>P</em> = 0.27, <em>P</em> = 0.34, respectively). Significant effects were found for the day of blood sampling, i.e., sampling time point, for AST (<em>P</em> &lt; 0.001), for GLDH (<em>P</em> &lt; 0.001), and for GGT (<em>P</em> &lt; 0.001). These effects of sampling day may be related to the administration of ethanol (the vehicle) to both the treatment and control groups. Based on the liver enzymes monitored in this small study, ostarine does not appear to alter liver function in idle adult horses receiving ostarine for 4 weeks. It is, however, possible that this study was underpowered to detect smaller differences between the groups. Larger future studies should investigate whether ostarine adversely affects other organs or body systems, and whether longer-term or multi-phase administration induces liver damage.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105446"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948009","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":"Impacts of rider skill level and weekly riding frequency on western riders’ identification of asymmetry","authors":"E. Jolley,&nbsp;A. Higgins,&nbsp;A. Logan","doi":"10.1016/j.jevs.2025.105458","DOIUrl":"10.1016/j.jevs.2025.105458","url":null,"abstract":"<div><div>Asymmetry of stirrup length has been found to impact rider symmetry and can influence rider position. Rider experience also has an influence on symmetry and position, with advanced riders more symmetric and vertically aligned compared with novice. To gain better insight to the understanding of rider asymmetry, a unique approach was performed by evaluating the rider's perception of induced asymmetry while riding in western tack. This study aimed to determine if novice and advanced riders could detect stirrup asymmetry in the same frequency while blinded to treatment. It was hypothesized advanced riders would detect asymmetric stirrups in greater frequency. Utilizing 10 stock-type university horses and 10 (5 advanced, 5 novice) university riders, participants tested specified stirrup treatments over 2 data collection days, with each rider riding the same horse twice. The order of the treatments was randomized, one ride having symmetric stirrups and the other asymmetric (one stirrup shortened by 10 cm). To blind riders to treatment, an equipment fit-check was performed to determine appropriate stirrup length, riders then dismounted and left the arena, allowing for stirrups to be adjusted via a randomized assignment. During this adjustment time, riders were instructed that their horses were being prepared for research, to aid in treatment blinding. Riders returned and remounted, performing a short riding pattern at the walk and trot, with directional changes. To confirm pattern completion, accuracy, and breaks of gait, all rides were videotaped. At the completion of the pattern for both rides, riders were asked to take a survey via Qualtrics, answering questions about their riding experience, the horse they rode, how often they rode per week, and any notes regarding asymmetry in their stirrup and rein length. Data were analyzed with a FREQ procedure in SAS 9. Similar amounts of advanced (60%) and novice (50%) riders correctly identified their stirrups. However, regardless of experience level, 70% of those riding more than 5 h per week and 50% of those riding 1–2 h per week correctly identified their stirrups as symmetric or asymmetric. Additionally, 100% of those riding 2–3, 3–4, and more than 5 h per week performed their pattern correctly, with only 67% of those riding 1–2 h per week doing so. Thus, weekly riding frequency may have an impact on asymmetry identification, not just riding experience. A rider's perception of asymmetry is of interest to the field of equitation science, and hours an individual rides per week may be a contributing factor to rider skills.</div></div>","PeriodicalId":15798,"journal":{"name":"Journal of Equine Veterinary Science","volume":"148 ","pages":"Article 105458"},"PeriodicalIF":1.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948209","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}