makecell, tabularx makecell, tabularx Background: Ageing and dental disease in horses lead to structural and functional deterioration of dental tissues, yet their molecular signatures remain poorly characterised. Understanding how these processes alter the protein composition of enamel, dentin, cementum and pulp is essential for improving equine oral health and identifying biomarkers of degeneration. Objectives: To characterise the proteomic profiles of equine dental tissues and determine age- and disease-associated changes, with the aim of identifying proteins consistently altered across conditions. Study design: Experimental ex vivo proteomic study. Methods: Fifteen equine cheek teeth were allocated to three groups (n = 5/group): mature adult, old and diseased. Label-free quantitative mass spectrometry was used to profile proteins across enamel, dentin, cementum and pulp. Differential abundance analysis and clustering assessed age- and disease-related effects. A Shiny-based interactive tool was developed for data exploration. Results: A total of 1,950 proteins were identified, with 58% unique to dental pulp. Ageing affected 329 proteins across all tissues, while disease impacted 379. Ageing consistently disrupted extracellular matrix (ECM) homeostasis in hard tissues. Cementum demonstrated increased catabolic markers the metalloproteinases -2 and -13. In dentin, the mineralisation protein dentin sialophosphoprotein was significantly reduced with age. Altered proteins in diseased pulp demonstrated predicted inhibition of ECM organisation (z-score = -3.05, p = 0.032) and elastic fibre formation (z-score = -2.82, p = 0.0033), while Retinoic Acid Receptor (RAR) activation was increased (z-score = 2.11, p = 0.006). Similarity analysis revealed overlapping molecular responses between ageing and disease. Main limitations: Small sample size and inclusion of only cheek teeth limit generalisability. Proteomic findings require functional validation. Conclusions: Ageing and disease induce distinct yet overlapping proteomic alterations in equine dental tissues, primarily affecting ECM homeostasis. A subset of consistently altered proteins may serve as targets for regenerative strategies, with implications for improving equine dental health and welfare.

Background: Dexmedetomidine infusions are beneficial in anaesthetised endotoxaemic horses when administered concurrent to endotoxin, but post-conditioning effects are unknown. Objectives: To evaluate whether a dexmedetomidine infusion is beneficial in horses administered Escherichia coli O55:B5 lipopolysaccharides (LPS) endotoxin prior to anaesthesia. Study design: Randomised controlled in vivo experiment. Methods: Ten systemically healthy horses were instrumented for acquisition of cardiac index (CI) using thermodilution. All horses received IV LPS (0.1 mcg/kg bwt) prior to anesthesia. Horses received IV xylazine (control, LPS; n = 5) or dexmedetomidine (treatment, LPS-Dex; n = 5), followed by IV ketamine and midazolam and sevoflurane in oxygen. In LPS-Dex, dexmedetomidine (1.75 μg/kg bwt/hr IV) was administered and target end-tidal sevoflurane concentration was reduced (1.8% versus 3% LPS). Cardiopulmonary function, acid-base, cytokine, and creatinine values were assessed every 30 minutes for 180 minutes. Data were compared between groups using mixed model analysis (p < 0.05). Results: Mean ± standard deviation CI was significantly higher in LPS-Dex at 30 and 60 minutes (57.9 ± 15.6 mL/min/kg bwt versus 43.1 ± 9.4, 30 minutes, p = 0.03; 60.2 ± 11.8 mL/min/kg bwt versus 38.9 ± 11.2, 60 minutes, p = 0.003). Creatinine was elevated and significantly higher in LPS from 90 minutes onward but remained normal in LPS-Dex throughout (201 ± 38 μmol/L versus 124 ± 26, 180 minutes, p = 0.003). Significantly improved base excess values were seen in LPS-Dex at 150 and 180 minutes (2.9 ± 2 mmol/L versus 0.6 ± 1, 150 minutes, p = 0.03; 3.4 ± 1.96 mmol/L versus 0.6 ± 1.41, 180 minutes, p = 0.01). Cytokine concentrations were similar between groups. Main limitations: The experimental protocol is not representative of all surgical colics. Conclusions: Dexmedetomidine infusion and concurrent reduction in inhalant anesthetic could benefit anesthetic management of horses even when endotoxaemia is already present.

Background: Information regarding mortality associated with standing procedures in horses is sparse. Objectives: To report data from > 12,000 standing sedations. Study design: Confidential, observational, prospective, multicentre, cohort study. Methods: Approved by the Ethical Committee of the Association of Veterinary Anaesthetists (2020-009), we collected records of horses/ponies undergoing standing sedation for surgery or advanced imaging using at least one top-up or constant rate infusion (CRI). Procedures were either NON-COLIC or COLIC. Outcome at seven days was recorded as i) ALIVE, ii) EUTHANASIA or iii) DEAD. Data were collected with a PDF questionnaire, which evolved into a webpage and processed with the statistical software R. Results: Data were collected from 12,307 standing sedations in 61 centres in 23 countries. Death rates were 0.15% overall (19/12,307), 0.13% for NON-COLICs (16/12,237) and 4.29% for COLICs (3/70). The causes of death in the 16 NON-COLICs were abdominal in ten (62.5%), fracture/refracture in three (18.75%), two were “found dead” (12.50%) and one (6.25%) for “other reasons”. In most cases premedication consisted of combinations of alpha-2-agonists/opioids with or without acepromazine. Sedation was maintained using top-ups (9,668/12,307), CRI (3,795/12,307) or CRI + top-up (1,156/12,307). Detomidine was the alpha2-agonist most frequently used for top up (8,258/12,307) and butorphanol the most common opioid (2,754/12,307). Detomidine was the most frequently used alpha-2-agonist for CRI (3,231/12,307); 364 and 305/12,307 received butorphanol and morphine respectively. Only 24.22% received fluid therapy. Locoregional anaesthesia was performed in 37.6% of the cases. Monitoring was minimal, with temperature (5.8%), ECG (3.8%) and pulse-oximetry (0.9%). Main limitations: Sample size, selection bias, questionnaire initially designed for general anaesthesias, potential human errors for data entry and potential missing cases.  Conclusions: Standing sedation in horses is not risk free. Horses die unexpectedly within seven days of sedation. Efforts should be made to reduce these mortality rates further.

Background: Equine foals receive IgG from mare colostrum through passive transfer. Failure of passive transfer (FPT) is a significant risk to the foal’s life, leaving them vulnerable to infection exposure and sepsis. Laboratory RID and immunoturbidimetric assays quantify IgG present in a foal sample but are time-consuming. Accurate, reproducible, stall-side testing to rapidly quantify IgG would allow for expedited clinical decisions, with potential to improve equine foal care and survival. Objectives: To evaluate the analytical and clinical performance of a stall-side IgG lateral-flow test and reader (Sidekick IgG), assessing its use as a point-of-care (POC) test to provide reliable results and agreement of IgG quantification with gold-standard methods. Study Design: Retrospective cohort Methods: Sidekick IgG test assessed with serial diluted foal sample (0-2000mg/dL, three replicates). Sidekick IgG compared to RID and Immunoturbidimetric assay. Serum/plasma samples from 10 foals created two cohorts, one representing successful passive transfer and one failed passive transfer. Agreement in IgG quantification between matched blood and plasma samples by the Sidekick IgG was tested for three foals. Results: Sidekick IgG test showed excellent recovery and high repeatability, 96.3% - 109.5% across clinically relevant range of 400-800mg/dL (CV% 3.7-10). Overall strong agreement with reference methods RID and Immunoturbidimetric assay. Strong agreement between matched whole-blood and plasma samples. Main Limitations: Small cohort (10 foals) Conclusions: Traditional laboratory-based assays have limitations such as need for specialised instrumentation, laboratory infrastructure, and skilled technical personnel. This is incompatible with the time-sensitive nature of many interventions and are particularly relevant in ambulatory or field-based equine practice, where access to laboratory services may be restricted. The stall-side Sidekick IgG assay delivers repeatable results enabling on-the-spot decisions and reducing delays from sample processing, transport and result reporting, with potential to enable informed decision-making on whether to initiate or continue treatment for a foal with FPT.

Background: A handheld smartphone-based computer vision algorithm (Anonymised (RH)) offers accessible alternatives for equine gait analysis but requires validation against a gold-standard multicamera optical motion capture system (Qualisys® (QS)). Objectives: To evaluate the accuracy and precision of RH in measuring vertical displacement signals (VDS) at the eye, withers, back, and croup in horses trotting on a straight line and on a circle. Study Design: Cross-sectional comparative validation study of a markerless computer vision algorithm. Methods: Fifty-nine horses were recorded while trotting on a straight line and 24 were lunged on a circle. RH detected two-dimensional anatomical keypoints on each frame, which were used to estimate a dynamic groundline and compute ground relative VDS with stride-based difference in maxima (Maxdiff) and minima (Mindiff). QS provided synchronous true VDS reference values. Agreement was evaluated using mean signed error (MSE), mean absolute error (MAE), and Bland-Altman analysis. Results: On the straight line (n = 2620 strides), the pooled stride-level MAE for Maxdiff and Mindiff was 3.8 mm. Keypoint-specific errors were 5.1 mm (eye), 4.3 mm (withers), and 3.0 mm (croup). On the circle (n = 2419 strides), pooled stride-level error increased to 5.5 mm. Trial-level analysis (n = 58 straight trials) showed much lower errors: 1.4 mm for both eye and withers and 1.1 mm for croup. On the circle (n = 24 trials), trial-level errors were higher, with 2.8 mm for the eye, 1.8 mm for the withers, and 3.3 mm for the croup. The back keypoint consistently showed the lowest errors across both stride- and trial-levels. Main Limitations: Croup Mindiff detection during circle trials had the highest error and bias. Conclusions: RH measured vertical displacement of the eye, withers, back, and croup with higher accuracy and precision than any previously reported markerless systems, supporting its use for equine gait analysis.

Background: The epidemiology of equine influenza (EI) in the United Kingdom (UK) has not been systematically described since the 2019 epidemic. Objectives: Summarise UK EI surveillance (2020–2024), quantify outbreak seasonality, and assess movement-related sources. Study design: Retrospective observational analysis of national surveillance and horse importation data. Methods: Epidemiological data for laboratory-confirmed EI cases in the UK were collated. Outbreaks were ≥1 case on a premises within four-weeks. Monthly outbreak counts were analysed using negative binomial regression with year, calendar-quarter and ordered quartiles of one-month lagged Irish exports to the UK for various equid commodity codes. A subset of traceable Q4-2022 sales-related outbreaks were mapped. Results: Epidemiological data were available for 149 cases on 126 premises. Outbreaks displayed a repeatable late-year pattern: Q4 (October–December) accounted for 52% (65/126), with a 3.25-fold higher per-month rate than the rest of the year. Over 75% of premises (95/126) reported a new arrival within ≤2 weeks, mostly the arrival being the index case; 56% (28/50) of index new-arrival cases with recorded origin came from Ireland. Q4 incidence exceeded Q1 (IRR 6.9, p<0.001) and years 2021–2024 incidence exceeded 2020 (IRRs 4.5–5.6, p<0.001). Adding lagged Irish imports of ‘equids other than pure-bred breeding animals’, improved fit and attenuated the Q4 effect (IRR 3.9, p<0.001), and identified higher import quartiles as predictors (quartile 3: IRR 4.5, p<0.001; quartile 4: IRR 3.7, p<0.001). ‘Total equid’ and ‘pure-bred breeding’ imports from Ireland were not consistently associated. Main limitations: Under-ascertainment; UK-wide exposure data versus GB-only outcomes; COVID-19 suppression of movements/testing in 2020. Conclusions: UK EI is characterised by a notable last-quarter risk window and strong links to horse movements. Trade in non–pure-bred horses aligns with outbreak timing and partly explains the seasonal excess. Control measures should prioritise vaccination of new horses prior to arrival, post-arrival quarantine and strengthened biosecurity during transport.

Background: Persistent breeding-induced endometritis (PBIE) is a common reason for mares failing to establish pregnancy. Objective: Examine the hypothesis that advancing mare age and embryo donor status predispose to PBIE and compromise fertility. Study design: Retrospective analysis of the impact of mare age, breeding system (embryo donor versus broodmare) and semen type (chilled versus frozen-thawed) on the likelihood of PBIE and subsequent pregnancy/embryo recovery. Methods: Warmblood mares(n=769) inseminated during 1745 oestrous cycles were divided into three age categories (≤ 6, 7-13 and ≥ 14 years) and as embryo donors versus broodmares. PBIE was defined as the detection of >2 cm intrauterine fluid from the day after insemination. Multivariable analysis was used to examine the effect of mare age, breeding system, semen type, inseminated cycle number, ovulation induction, oestrus induction, reproductive status (barren, foaling, maiden), treatment for fluid accumulation (mostly oxytocin and/or uterine lavage) and time of year (month) on the incidence of PBIE and pregnancy/embryo recovery. Results: The likelihood of developing PBIE (27.6% of all cycles) was higher in older mares (≥ 14 years: odds ratio (OR) 7.81) and ET donors (OR 1.58) but reduced in foaling mares (OR 0.14) or when using frozen semen (OR 0.39). Pregnancy or embryo recovery was lower (OR 0.36) for frozen-thawed (39.6%) than chilled-transported (58.3%) semen, and in older mares (OR 0.6), but was improved by ovulation induction (OR 1.5) and not significantly affected by PBIE (p=0.2), suggesting that treatment was usually sufficient to mitigate the negative effects of PBIE. Main limitation: Retrospective data from multi-veterinarian clinic; mare status and pregnancy data missing from some cases. Conclusions: Advancing mare age increases the likelihood of PBIE and compromises fertility; although embryo donor status and chilled semen use increase the odds of PBIE, effects on fertility are minimized by simple treatments.

Background Equine aural plaque caused by equine papilloma viruses is common worldwide, affected horses can show severe clinical signs. In some countries affected horses are not allowed in competitions or shows due to viral etiology. Since lesions persist, showing no spontaneous regress, effective and safe treatment is desired. Today, the only treatment with consistent efficacy is imiquimode (Aldara®). Treatment time is long and adverse effects common, sometimes so severe that treatment cannot be completed. In humans even pediatric, papilloma warts are successfully, safely treated with topical nitric-zinc complex solutions inducing a painless caustic effect. Objectives The objective to retrospectively evaluate effectiveness and adverse effects with topical treatment with a solution containing nitric acid and zinc (Oxalic® or Verrutop®). Comparing this treatment with results from published studies using imiquimod (Aldara®). Study design Retrospective case series. Methods Records from horses with aural plaque diagnosed at Equine Clinic of the University Animal Hospital and Equine Clinic Täby Sweden during 2012-2022 were reviewed. Included horses were treated topically with nitric acid and zinc solution (Oxalic® or Verrutop®), uni- or bilateral every other week until remission, successful outcome defined as no remaining lesions during a 12-28 month follow up. Results Twelve horses were included, eight bilaterally affected. In total were 20 ears treated, in 17 lesions healed with one to five treatments, several needed only one. The three remaining ears, substantially improved, the horses showing no clinical signs. Treatment period varied between two to 20 weeks, none developing adverse effects. Compared with imiquimod (Aldara®), treatments occasions were fewer, no adverse effects were seen, whereas painful ulcerations and erosions were recorded in all imiquimod (Aldara®) treated horses. Main limitations Retrospective study, small sample size, not blinded, and no control group included. Lesions were diagnosed by macroscopic appearance, no PCR for virus detection or histology were made.

A document by Emma Fairbanks. Click on the document to view its contents.

Background: Strangles, caused by Streptococcus equi subspecies equi ( S. equi), is a prevalent infectious disease of horses. This is the first report on protection conferred by a new vaccine, Strangvac, against natural infection. Objectives: To measure the effects of Strangvac vaccination during an outbreak of strangles at a Swedish farm. Study Design: Longitudinal cohort study. Methods: Healthy horses ( n=17) were vaccinated on day 0, which occurred 23 days after strangles was first confirmed in three unvaccinated horses on the same farm. Blood serum samples were collected on day 0, day 28 and day 489. A combined iELISA was used to measure total antibody titres towards the components of the vaccine. Specific antibody levels in blood sera to S. equi were also quantified using the antigen A/C iELISAs, which can differentiate infected from vaccinated animals. Clinical signs were monitored. Results: All vaccinated horses had increased total antibody titres to CCE, Eq85 and/or IdeE from day 0 (2.50±0.28) to day 28 (3.63±0.31; p<0.0001). Seropositivity in the antigen A/C iELISA was noted in 8/17 healthy horses on day 0 (prior to vaccination), in 9/16 vaccinates on day 28, and in 3/3 unvaccinated clinical cases on day 28. None of the vaccinated horses developed strangles, but 5/7 of the original vaccinated horses tested seropositive in the A/C iELISA on day 489, which was 377 days after their third vaccination. Main limitations: Aside from the three unvaccinated clinical cases, no unvaccinated control group was available. Conclusions: Despite adherence to recommended biosecurity measures, serological evidence of exposure to S. equi was demonstrated in half of the vaccinated horses. Notably, all horses vaccinated during the outbreak responded to the vaccine components and remained healthy, supporting the protective effects of vaccination of healthy horses with Strangvac in outbreak situations.

BACKGROUND Intra-articular (IA) corticosteroids significantly affect glucose and insulin concentrations, which is of particular concern in horses with insulin dysregulation (ID) due to a heightened risk of laminitis. Sodium glucose cotransporter 2 inhibitors (SGLT2i), a drug class that is being utilized more commonly in horses with insulin dysregulation, could potentially be used to control post-IA corticosteroid hyperinsulinemia. OBJECTIVES To determine whether pre-treatment with the SGLT2i drug ertugliflozin could decrease the IA corticosteroid-induced hyperinsulinemic response in metabolically normal horses METHODS Prospective, controlled, cross-over study design. Eight mixed-breed, metabolically normal geldings either received no treatment (CTL) or were treated with ertugliflozin (ERT) for 7 days before and 7 days after a total dose of 18mg of IA triamcinolone acetonide (TA). Samples for resting glucose and insulin concentrations, as well as dynamic oral sugar testing (OST), were collected. Treatments were crossed over and the study repeated. Two-way, repeated measures analysis of variance was used to identify timepoint by treatment differences ( P < 0.05). RESULTS Resting glucose concentrations were significantly lower in the ERT group at 8hr ( P = 0.042), 12hr ( P = 0.002), 24hr ( P < 0.001), and 48hr ( P < 0.001) while resting insulin concentrations were significantly lower in the ERT group at 12hr ( P = 0.021), 24hr ( P < 0.001), 48hr ( P = 0.020), and 72hr ( P < 0.001) post-IA injection. Insulin was significantly lower two days after IA TA in the ERT group at 60min post-OST ( P = 0.041). MAIN LIMITATIONS Metabolically normal horses, rather than insulin dysregulated horses, were used. CONCLUSIONS Pre-treatment with ertugliflozin decreases the glucose and insulin changes following IA corticosteroid administration in metabolically normal horses. Further investigation of this treatment strategy in insulin dysregulated horses is warranted as it may mitigate metabolic changes and reduce risk factors when administering IA corticosteroids.

Science-in-brief: Report on the 2nd Dorothy Russell Havemeyer Foundation workshop on acute colitis of the adult horseLuis G. Arroyo, Department of Clinical Studies, University of Guelph, Guelph, Ontario N1G 2W1, Canada larroyo@uoguelph.caAshley E. Whitehead, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta T2N 4Z6, Canada ae.whitehead@ucalgary.caFrancisco Uzal, California Animal Health and Food Safety Laboratory, San Bernardino, 92408-2113, USA University of California, California fuzal@cafhs.ucdavis.edu

Background: Lyme arthritis, a well-documented subtype of arthritis in humans and dogs, is caused by Borrelia burgdorferi and spread primarily through ticks (Ixodes spp.). While Lyme disease in horses is known to cause a variety of clinical signs, its involvement in the development of equine arthritis is controversial. As climate change enables tick populations to expand, more horses could be exposed to B. burgdorferi, therefore a greater understanding of how Lyme disease affects joints is critical to preserve soundness. Objectives: To investigate potential correlations between systemic B. burgdorferi infection and chemokine and cytokine inflammatory marker levels within synovial fluid. Study design: In vivo experiment. Methods: Synovial fluid samples were collected at the start of routine joint injection or immediately prior to surgery and analyzed for chemokine and cytokine levels. Serum samples from each horse were tested for outer surface protein (OSP) markers via Lyme Multiplex. Results: Six of twenty-five enrolled horses (24%) tested positive for at least one Lyme outer surface protein marker (OSP A 0/6; OSP C 2/6, OSP F 6/6; mean age 11.17±6.31 years), and three more horses had an equivocal result (OSP A 0/3; OSP C 1/3, OSP F 3/3; mean age 11.67±2.62 years). While most synovial inflammatory markers showed no statistical difference between systemic, serologic Lyme infection status and presumed arthritic joints (p=0.1261-0.7199) or trauma-associated joints (p=0.4560-0.9999), we observed a noteworthy negative association between CCL2 synovial fluid levels and systemic Lyme status (p=0.0142). Main limitations: Sample size was a primary limitation. Conclusions: The negative association observed between CCL2 synovial fluid levels and systemic Lyme status was also present in arthritic joints of horses with systemic B. burgdorferi infection. Notably, this contrasts with past reports of increased synovial fluid CCL2 levels associated with Lyme arthritis in other species.

Background:Equid alphaherpesvirus 1 (EHV-1) remains a major concern for the equine industry, with recent outbreaks at international equestrian events highlighting the need for improved surveillance during competitions. Objectives:To investigate EHV-1 and -4 presence in shared airspaces and environmental surfaces in direct contact with horses at international equestrian events, and to evaluate air sampling as a surveillance alternative to individual horse testing. Study design:A cross-sectional field study. Methods:Air (37) and surface samples (205) were collected from temporary stabling facilities across six events in Spain and 2 in the U.S. at different seasons over 10 months. Viral DNA (genomic copies) was measured and quantitated by quantitative and digital PCR. During all Spain events, we sampled air twice, early evening vs nighttime. Results:EHV-1 was frequently detected in the air in 20/28 samples in Spain, in all 3 samples from Florida, and in 3/6 samples from Kentucky, U.S. Surface samples were positive 15.6% in Spain, 26.3% in Florida, and 0.0% in Kentucky. EHV-4 was found in air samples at rates of 12/28 in Spain, 5/6 in Kentucky, and 0/3 in Florida, with surface detection of 1.6% in Spain and 7% in Kentucky. No significant differences were observed between daytime (high activity) and nighttime (low activity) airborne viral loads, suggesting that daytime horse movement and management practices had minimal impact on detection levels in our study. A positive correlation (Cohen’s κ= 0.401) and moderate agreement between surface and air positivity for EHV-1 emphasized the potential of air sampling as a non-invasive, cohort-based surveillance tool. Main limitations:The study did not isolate infectious viruses, only molecular detection was employed, which limits conclusions about transmission risk. Conclusions:These findings underscore the utility of air sampling for early EHV-1 detection at mass gatherings, although further validation is needed to connect genomic detection to active shedding and viral infectivity.

Background: Physical restraint of horses for veterinary procedures is necessary to allow completion of tasks effectively and without injury to patient or personnel. Objectives: Comparison of physiological effects and behavioural responses to four commonly used restraint techniques for upper respiratory tract (URT) endoscopy in unsedated horses. Study design: Blocked and randomised interventional study. Methods: Twelve university owned teaching horses were blocked into groups of four and randomly allocated to one of four restraint methods (nose twitch, ear hold, Stableizer® and nil restraint) for URT endoscopy. Horse response to restraint and endoscopy was evaluated subjectively and by objective measures of procedural efficacy (duration and head movement), time domain indices of heart rate variability (HRV), saliva cortisol and plasma β-endorphin concentrations. Results: Horses demonstrated strong individual differences for procedure tolerance and preferred method of restraint, but there were no differences observed in outcome measures related to procedural efficacy or neuroendocrine response associated with restraint type. Repetition of experimental procedures was associated with progressive decrease in mean (95% CI) minimum heart rate from 34.2 (31.7-36.7) to 30.1 (28.0-32.2) bpm (P<0.001), and increased HRV measures related to parasympathetic dominance. Cortisol was greatest on Day 2 (1.5, 1.1-2.5 nmol/L; median, 95% CI), compared with Day 1 (0.8, 0.5-1.6 nmol/L; P=0.016), associated with interactions with novel personnel. Main limitations: Convenience sample of horses familiar with most study interventions; intervention was minimally invasive and of short duration. Conclusions: Study findings did not support current recommendations to prioritise one type of restraint over other available techniques.

Background: Infection with Streptococcus equi subspecies equi ( S. equi) is characterised by acute disease with about 10% of infected animals entering a carrier state. Clinically, infection with S. equi cannot readily be distinguished from infection caused by other respiratory pathogens including Streptococcus equi subsp. zooepidemicus ( S. zooepidemicus), equine influenza virus and equine herpes virus. Screening protocols, with appropriate quarantining facilities, are important to detect carriers of S. equi and avoid strangles outbreaks. Objectives: Evaluate the effectiveness of the screening process implemented at a UK welfare centre to prevent introduction of strangles. Study design: Retrospective cross-sectional study. Methods: Clinical records of 626 equids admitted to a UK welfare centre between 2017 and 2021 and from horses that developed respiratory signs after admission were reviewed. Results: The screening protocol, which included a clinical examination, paired serology samples (iELISA) taken 6 weeks apart, and bilateral guttural pouch endoscopy to identify abnormalities such as chondroids with lavage for quantitative PCR and culture analysis for S. equi (and often S. zooepidemicus) detected 34 potential carriers of S. equi or S. zooepidemicus. Of these, 24 (3.8%) were PCR-positive for S. equi, 8 were PCR/culture positive for S. zooepidemicus and 2 were PCR/culture negative but had chondroids. Bilateral guttural pouch endoscopy, with PCR analysis of lavage material, was the most cost-effective method of detecting S. equi carriers. There were no cases of strangles within the general herd after screening and admission of new horses. Main limitations: Variation in the level of detail of clinical records. Conclusions: The screening process resulted in the identification of carriers and maintained a strangles-free herd. Further research is required to elucidate the significance of S. zooepidemicus infection in the guttural pouch.

TITLE Report from the 2025 Dorothy Russell Havemeyer Foundation meeting on Equine Gastric Ulcer Syndrome (EGUS): Advances in the field. AUTHORS AND AFFILIATIONS Benjamin W. Sykes; b.sykes@uq.edu.au; BW Sykes Consultancy, Coffs Harbour, NSW, Australia. Gayle D. Hallowell: gayle.hallowell@medicine.vet; Medicine Vet Equine Referrals, Melton Mowbray, UK. Frank M. Andrews; fandrews@lsu.edu; Equine Health and Sports Performance, Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisianna State University. The full names of the authors, email addresses, and the institutional affiliations where the work was conducted. KEYWORDS N/A FUNDING INFORMATION Dorothy Russell Havemeyer Research Foundation and Boehringer Ingelheim. ACKNOWLEDGEMENTS N/A CONFLICT OF INTERESTS B.W.S. has active consultancy or research engagements with Kelato Australia, Kelato USA, MDS-Vet, MAI Animal Health, and Mayohealth, and within the past 3 years, has provided research, consultancy or educational services for Abbey Laboratories, A-Vet, Health Food Symmetry, Hong Kong Jockey Club, Kentucky Equine Research, and Salfarm Denmark, all of whom have products within the EGUS space. G.D.H. has affiliations with Salfarm Denmark having provided consultancy services; this company has products in the EGUS space. F.M.A. consults and has had funded grants from Boehringer Ingelheim Animal Health, which has medications in the EGUS space. See Section 4.7. If there are none to disclose, please include the following statement below: ‘The authors have declared no conflicting interests’. DATA INTEGRITY STATEMENT N/A ETHICAL ANIMAL RESEARCH N/A INFORMED CONSENT N/A ANTIMICROBIAL STEWARDSHIP POLICY N/A DATA AVAILABILITY STATEMENT Data sharing is not applicable to this article as no new data were created or analysed in this study.

Background: Significant distal interphalangeal joint (DIPJ) pathology can occur with few radiographic findings but can be accompanied by joint capsule enthesopathy on the middle phalanx. Objectives: To explore the associations and correlations between DIPJ capsule enthesopathy identified radiographically and DIPJ articular cartilage abnormalities and other concurrent soft tissue or osseous pathology within the foot found on MRI. Study Design: Retrospective and descriptive case series. Methods: Cases identified with DIPJ capsule enthesopathy were retrospectively reviewed. Abnormalities were graded using a 4-point scale. Descriptive statistics and Spearman’s rank correlations were used to analyze the relationship between the presence and grade of DIPJ capsule enthesopathy, lameness, and DIPJ intra- and extra-articular abnormalities. Results: Twenty-one MRI scans and radiographs with DIPJ capsule enthesopathy were analyzed. DIPJ articular cartilage lesions were identified in 20/21 limbs (95%). There was no significant correlation between the degree of DIPJ capsule enthesopathy and severity of articular cartilage lesions. DIPJ proliferative synovitis and osteophytes were present in majority of limbs (91% and 95%), respectively. DIPJ collateral ligaments were abnormal in 52% of the limbs. DIPJ capsule enthesopathy grade was moderately positively correlated with DIPJ collateral ligaments’ findings severity (p=0.01). Main Limitations: Retrospective character, no histopathology, studied cases limited to one referral center. Conclusions: The presence of DIPJ capsule enthesopathy on radiographs is a reliable finding to rule in DIPJ damage and support further case management, particularly in cases where advanced imaging is unavailable or desired.