Summary Background Anthelmintic resistance in equine parasites is increasing; frequent anthelmintic use accelerates it. Objectives To investigate how horse owners use diagnostic testing and anthelmintics to control intestinal parasites. Study design Cross‐sectional study conducted through an online questionnaire of UK horse owners. Methods The questionnaire (combination of multiple choice, Likert scale and free text questions) was distributed via practices, equestrian organisations, etc. from December 2021 to October 2022. Descriptive and inferential statistics were performed in Microsoft Excel and IBM SPSS. Results There were 4232 usable responses. Owners of horses on livery yards were less likely to make anthelmintic‐use decisions than those on private properties ( p < 0.001); managers made decisions in 39.6% of horses on livery yards. Over half (52.0%) administered anthelmintics based on faecal egg counts (FECs)/tapeworm ELISA results, but 30.0% gave anthelmintics at least annually regardless of any results. Owners who sought veterinary advice were more likely to administer anthelmintics based on test results (both p < 0.001). The frequency of routine worming was higher if they did not test ( p < 0.001); 88.9% wormed all horses on pasture at the same time. Moxidectin was the first choice for 82.2% of owners. Regular FECs were performed by 84.7%, higher for those who sought veterinary advice (89.3%, p < 0.001). Tapeworm ELISAs were utilised by 40.8%, higher for those on a health programme (68.1%; p < 0.001); 58.5% were routinely treated for tapeworms regardless of test results. Main limitations Selection bias and social desirability bias. Horse owners were asked to complete the survey for one horse only. Conclusions The uptake of diagnostic testing, particularly FECs, was higher than previously reported, but routine anthelmintic use was still common. Horse owners who sought advice from their veterinarian, or whose horse was enrolled in a health programme, were more likely to take a diagnostic‐led approach to parasite control.

Summary Background Anthelmintic resistance in equine parasites is increasing. Pasture management is a vital component of helminth control; its implementation is key to reducing anthelmintic dosing frequency to reduce selection pressure for resistance. Objectives To investigate how horse owners use management procedures to control common intestinal parasites in horses. Study design Cross‐sectional study conducted through an online questionnaire of UK horse owners. Methods The questionnaire (combination of multiple choice, Likert scale and free‐text questions) was distributed via practices, equestrian organisations, etc., from December 2021 to October 2022. Respondents were asked about pasture management, diagnostic testing and worm‐associated illnesses. Descriptive and inferential statistics were performed in Microsoft Excel and IBM SPSS. Results There were 4232 usable responses. Only 21.5% of respondents alternated or co‐grazed their horse with ruminants (higher for horses grazing on private properties compared to horses grazing on livery yards; p < 0.001). The majority of owners (73.3%) removed faeces from pastures (poo‐picking), of which 86.4% removed faeces twice a week or more. Owners of horses pastured individually were more likely to poo‐pick (89.8%) than horses pastured in groups (68.9%; p < 0.001). The majority of respondents (77.1%) rested pastures, but less than 5% for over 6 months. Only 5.1% of owners reported they had experienced illnesses related to worms in any horse (commonest clinical signs were colic and weight loss). Main limitations Risk of selection bias and social desirability bias. Some aspects of pasture management (e.g. stocking density) were not included. Horse owners were asked to complete the questionnaire for one horse only. Conclusions Many owners (>25%) are not routinely poo‐picking, and the majority are not co/alternate grazing or resting pastures effectively, identifying opportunities to improve parasite control. Optimising management practices should reduce the requirements for using anthelmintics to achieve parasite control, thereby reducing selection pressure on the development of resistance.

The metabolic and lipid profiles of horses treated with sodium-glucose cotransporter 2 inhibitors are not well understood. This retrospective study evaluated blood parameters in hyperinsulinemic horses treated with either ertugliflozin (0.05 mg/kg) or dapagliflozin (0.02 mg/kg) orally once daily. Blood samples were collected at baseline (day 0) and after 7 and/or 30 days of treatment. Statistical analyses were conducted using Wilcoxon signed-rank, Mann-Whitney and Spearman's rank correlation tests. Thirty-four horses received dapagliflozin and 24 received ertugliflozin. Significant (p<0.05) within-horse changes between day 0 and day 30 included [median, inter-quartile range (IQR)]: basal serum [Insulin] (uU/ml) reduced 170 (92-280) to 28.7 (14.5-90); [triglycerides] (mmol/l) increased 0.5 (0.3-0.6) to 1.0 (0.6-1.56), [β-hydroxybutyrate] (umol/l) increased 0.22 (0.17-2.7) to 0.30 (0.24-0.35); [total cholesterol] (mmol/l) increased 2.36 (2-2.6) to 2.84 (2.4-3.7); and GGT (IU/ml) increased 21 (16-32) to 25 (18-38). As a percentage of total serum lipids, high-density lipoprotein (HDL) reduced 52.4% (47.9%-61.0%) to 50% (41%-54.8%) and very-low density lipoprotein (VLDL) increased 10.4% (6.4%-14.4%) to 12.3% (9.9%-16.8%) (all p<0.05). Differences between ertugliflozin and dapagliflozin groups were not significant in any of these parameters at days 0, 7 or 30. At day 30, 10/48 (21%) cases had [triglycerides] > 2.0mmol/l (maximum = 10.8mmol/l). Day 30 [triglyceride] correlated with day 0: basal insulin (rho=0.47); [triglyceride] (rho=0.42); %VLDL (rho=0.34) day 30: [total cholesterol] (rho=0.67), %HDL (rho=-0.432) and %VLDL (rho=0.708). Our findings suggest that SGLT2 inhibitors induce minor changes in lipid profiles, with occasional cases of marked hypertriglyceridemia, and that dapagliflozin and ertugliflozin exhibit similar biochemical effects.

BackgroundYoungstock are particularly susceptible to parasitic disease; anthelmintic resistance is an increasing problem.ObjectivesTo investigate the current approaches to testing for parasites and anthelmintic use in foals and adult horses on UK studs.Study DesignCross-sectional study; online survey.MethodsSurveyMonkey questionnaires (multiple choice, Likert scale and free text questions) distributed via practices, press, social media and snowball sampling. Descriptive and inferential statistics performed in Microsoft Excel and STATA. Statistical differences assessed with Fisher's exact test or Mann-Whitney U test.ResultsThere were 56 usable responses. Experience, faecal egg counts and veterinary advice were considered to be the most important factors in determining anthelmintic choice. The commonest product choices overall were a moxidectin-praziquantel combination, fenbendazole and pyrantel. Timing of anthelmintic treatment for cyathostomins in broodmares was based on faecal egg counts in 58.9%; treatment for tapeworms was based on ELISA results in 10.7%. With respect to foals, 61.8% received anthelmintic treatments regardless of test results; the commonest anthelmintic products used in foals were fenbendazole (56.6%) and pyrantel (47.9%). Anthelmintic resistance on the property was reported by 27.8% of respondents, but there was no association with reported illness.Main LimitationsSmall sample size. Potential selection bias and response bias.ConclusionsOver a quarter of stud owners believed that anthelmintic resistance occurred on their premises. The commonest used anthelmintic product on stud farms was moxidectin-praziquantel combination. The commonest anthelmintic used in foals was fenbendazole. Testing for tapeworms was uncommonly undertaken. Results identify areas where testing for parasites and anthelmintic use on stud farms could be improved.

Background: Youngstock are susceptible to parasitic disease, and the development of anthelmintic resistance is increasing. Objectives: To investigate stud owners'/managers' perceived prevalence of parasite-associated diseases and current management approaches to control parasites in UK studs. Study Design: A cross-sectional study by an online survey. Methods: SurveyMonkey questionnaires (multiple choice, Likert scale and free text questions) distributed via practices, press, social media and snowball sampling. Descriptive and inferential statistics were performed in Microsoft Excel and STATA, and statistical differences were assessed with Fisher's exact test, Mann-Whitney U or Kruskal-Wallis tests. Results: Fifty-six usable responses were collated. The median number of foals born per farm per year was 9, and the median number of resident mares/permanent boarders was 14. The predominant breeds were Thoroughbreds and Warmbloods. Perceived parasite-associated illness in the past year was reported by 35.7% of respondents (weight loss (65.0%), diarrhoea (40.0%), colic (15.0%)), with young adults (1-3 years) most affected (47.7%), followed by adults (31.8%), weanlings (27.3%) and foals (20.5%). New mares were reportedly only turned out after anthelmintic administration by 53.6% of respondents, whilst 41.1% performed faecal egg counts and treated, if necessary, prior to turnout and 16.1% turned mares out without treating or testing. The median stocking density was 0.3 mares/acre (significantly lower for Thoroughbreds than Warmbloods or 'others' (p < 0.01)). Poo-picking was never performed on 32.1% of farms, while 89.3% harrowed paddocks and 57.1% co-grazed horses with ruminants. Main Limitations: Small sample size and the potential for selection and response biases. Conclusions: Parasite-associated diseases on stud farms are perceived to be common. Many farms fail to implement management practices (e.g. poo-picking, co-grazing with ruminants) that could reduce the risk of parasite transmission on the premises. Harrowing paddocks could increase the risks of parasite transmission. Results identify areas where management practices should be improved.

BACKGROUND:There is a lack of consensus on how best to balance our need to minimise the risk of parasite-associated disease in the individual horse, with the need to limit the use of anthelmintics in the population to preserve their efficacy through delaying further development of resistance.OBJECTIVES:To develop evidence-based guidelines utilising a modified GRADE framework.METHODS:A panel of veterinary scientists with relevant expertise and experience was convened. Relevant research questions were identified and developed with associated search terms being defined. Evidence in the veterinary literature was evaluated using the GRADE evidence-to-decision framework. Literature searches were performed utilising CAB abstracts and PubMed. Where there was insufficient evidence to answer the research question the panel developed practical guidance based on their collective knowledge and experience.RESULTS:Search results are presented, and recommendation or practical guidance were made in response to 37 clinically relevant questions relating to the use of anthelmintics in horses.MAIN LIMITATIONS:There was insufficient evidence to answer many of the questions with any degree of certainty and practical guidance frequently had to be based upon extrapolation of relevant information and the panel members' collective experience and opinions.CONCLUSIONS:Equine parasite control practices and current recommendations have a weak evidence base. These guidelines highlight changes in equine parasite control that should be considered to reduce the threat of parasite-associated disease and delay the development of further anthelmintic resistance.

SummaryWhile there are limited data on the environmental impact of administering equine parasiticide drugs, evidence from other species indicates significant negative ecological effects. Anthelmintic drugs are excreted unchanged or metabolised to other active and/or toxic metabolites that enter the environment through direct excretion. These chemicals can have significant toxic effects on insects, such as dung beetles, earthworms and aquatic animals. Of the frequently used equine anthelmintics, ivermectin is the most ecotoxic; available evidence indicates that moxidectin is less toxic and fenbendazole appears to have little impact on dung‐colonising insects but may be toxic to aquatic organisms and fungi. There are little data regarding the ecotoxicity of pyrantel and praziquantel, although their ecotoxic effects are thought to be low. Pasture hygiene reduces pharmaceutical contamination and also helps to break the endoparasitic cycle of infectivity, thus reducing reliance on anthelmintics. Judicious and targeted use of endoparasiticides, along with pasture hygiene measures, will limit the ecotoxic effects of these drugs as well as reduce the selection pressure that drives anthelmintic resistance. Anthelmintics may also negatively impact the equine gastrointestinal microbiota. Ectoparasiticides (such as fipronil, permethrin and cypermethrin) may also have significant negative ecological effects, with a risk of contamination of both the immediate environment and water courses following topical use of these drugs. The half‐life of fipronil in the environment is variable, but it degrades into compounds which are more toxic; for example, it is highly toxic to bees and is reported to bioaccumulate in fish and can be toxic to birds. Of the synthetic pyrethroids, permethrin degrades at a faster rate than cypermethrin and may therefore have a lower ecotoxic effect. The ecotoxic effects of injectable doramectin are likely to be similar to oral ivermectin, although persistence in faeces may be significantly prolonged compared to the oral treatment route for ivermectin.

Summary Background Preliminary evidence indicates that ertugliflozin benefits horses and ponies (hereafter collectively referred to as horses) with hyperinsulinaemia and hyperinsulinaemia‐associated laminitis. The effects of ertugliflozin on the results of the oral sugar test used widely in the assessment of insulin dysregulation (ID), have not been reported. Objectives To report the effects of ertugliflozin on responses to the oral sugar test (OST) in horses with ID. Study design Retrospective case series. Methods Clinical records were reviewed to identify horses with ID that had an OST (0.45 mL/kg Karo‐Light PO) performed before and after 4 days of treatment with 0.05 mg/kg ertugliflozin PO s.i.d. Pre‐ and post‐treatment insulin concentrations were compared using Wilcoxon sign‐ranked tests. Results Ten horses with ID met the inclusion criteria. Significant reductions in plasma insulin concentration were identified at all time points after 4 days of treatment with ertugliflozin relative to pre‐treatment values. At T0 (prior to oral sugar), median insulin concentration reduced from 22.4 μu/mL (IQR: 6.5, 39) pre‐treatment to 4.8 μu/mL (IQR: 3.7, 9.2) at day 4 ( p = 0.004). At T60 (60 min after oral sugar), median insulin concentration was 165 μu/mL (IQR: 61.2, 222) pre‐treatment and 78.1 μu/mL (IQR: 30.5, 137) at day 4 ( p = 0.004). At T90 (90 min after oral sugar), median insulin concentration was 170 μu/mL (IQR: 88.6, 269) pre‐treatment and 84.7 μu/mL (IQR: 28.7, 122) at day 4 ( p = 0.002). Serum triglyceride concentration increased from a median of 0.4 mmol/L (IQR: 0.2, 0.8) pre‐treatment to 0.9 mmol/L (IQR: 0.6, 2) at day 4 of ertugliflozin treatment ( p = 0.006). Main limitations A small heterogenous group of horses and ponies, some with PPID, were used in the absence of a control group. Conclusions Four daily doses of ertugliflozin at 0.05 mg/kg was associated with lowering of insulin concentrations at baseline and in response to an OST in horses with ID; however, insulin levels did not return to normal in all horses. Increases in triglyceride concentrations were also observed.

BACKGROUND:Pituitary pars intermedia dysfunction (PPID) is a prevalent, age-related chronic disorder in equids. Diagnosis of PPID can be challenging because of its broad spectrum of clinical presentations and disparate published diagnostic criteria, and there are limited available treatment options.OBJECTIVES:To develop evidence-based primary care guidelines for the diagnosis and treatment of equine PPID based on the available literature.STUDY DESIGN:Evidence-based clinical guideline using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework.METHODS:Research questions were proposed by a panel of veterinarians and developed into PICO or another structured format. VetSRev and Veterinary Evidence were searched for evidence summaries, and systematic searches of the NCBI PubMed and CAB Direct databases were conducted using keyword searches in July 2022 and updated in January 2023. The evidence was evaluated using the GRADE framework.RESULTS AND RECOMMENDATIONS:The research questions were categorised into four areas: (A) Case selection for diagnostic testing, pre-test probability and diagnostic test accuracy, (B) interpretation of test results, (C) pharmacological treatments and other treatment/management options and (D) monitoring treated cases. Relevant veterinary publications were identified and assessed using the GRADE criteria. The results were developed into recommendations: (A) Case selection for diagnostic testing and diagnostic test accuracy: (i) The prevalence of PPID in equids aged ≥15 years is between 21% and 27%; (ii) hypertrichosis or delayed/incomplete hair coat shedding provides a high index of clinical suspicion for PPID; (iii) the combination of clinical signs and age informs the index of clinical suspicion prior to diagnostic testing; (iv) estimated pre-test probability of PPID should be considered in interpretation of diagnostic test results; (v) pre-test probability of PPID is low in equids aged <10 years; (vi) both pre-test probability of disease and season of testing have strong influence on the ability to diagnose PPID using basal adrenocorticotropic hormone (ACTH) or ACTH after thyrotropin-releasing hormone (TRH) stimulation. The overall diagnostic accuracy of basal ACTH concentrations for diagnosing PPID ranged between 88% and 92% in the autumn and 70% and 86% in the non-autumn, depending on the pre-test probability. Based on a single study, the overall diagnostic accuracy of ACTH concentrations in response to TRH after 30 minutes for diagnosing PPID ranged between 92% and 98% in the autumn and 90% and 94% in the non-autumn, depending on the pre-test probability. Thus, it should be remembered that the risk of a false positive result increases in situations where there is a low pre-test probability, which could mean that treatment is initiated for PPID without checking for a more likely alternative diagnosis. This could compromise horse welfare due to the commencement of lifelong therapy and/or failing to identify and treat an alternative potentially life-threatening condition. (B) Interpretation of diagnostic tests: (i) There is a significant effect of breed on plasma ACTH concentration, particularly in the autumn with markedly higher ACTH concentrations in some but not all 'thrifty' breeds; (ii) basal and/or post-TRH ACTH concentrations may also be affected by latitude/location, diet/feeding, coat colour, critical illness and trailer transport; (iii) mild pain is unlikely to have a large effect on basal ACTH, but caution may be required for more severe pain; (iv) determining diagnostic thresholds that allow for all possible contributory factors is not practical; therefore, the use of equivocal ranges is supported; (v) dynamic insulin testing and TRH stimulation testing may be combined, but TRH stimulation testing should not immediately follow an oral sugar test; (vi) equids with PPID and hyperinsulinaemia appear to be at higher risk of laminitis, but ACTH is not an independent predictor of laminitis risk. (C) Pharmacologic treatments and other treatment/management options: (i) Pergolide improves most clinical signs associated with PPID in the majority of affected animals; (ii) Pergolide treatment lowers basal ACTH concentrations and improves the ACTH response to TRH in many animals, but measures of insulin dysregulation (ID) are not altered in most cases; (iii) chasteberry has no effect on ACTH concentrations and there is no benefit to adding chasteberry to pergolide therapy; (iv) combination of cyproheptadine with pergolide is not superior to pergolide alone; (v) there is no evidence that pergolide has adverse cardiac effects in horses; (vi) Pergolide does not affect insulin sensitivity. (D) Monitoring pergolide-treated cases: (i) Hormone assays provide a crude indication of pituitary control in response to pergolide therapy, however it is unknown whether monitoring of ACTH concentrations and titrating of pergolide doses accordingly is associated with improved endocrinological or clinical outcome; (ii) it is unknown whether monitoring the ACTH response to TRH or clinical signs is associated with an improved outcome; (iii) there is very weak evidence to suggest that increasing pergolide dose in autumn months may be beneficial; (iv) there is little advantage in waiting for more than a month to perform follow-up endocrine testing following initiation of pergolide therapy; there may be merit in performing repeat tests sooner; (v) timing of sampling in relation to pergolide dosing does not confound measurement of ACTH concentration; (vi) there is no evidence that making changes after interpretation of ACTH concentrations measured at certain times of the year is associated with improved outcomes; (vii) evidence is very limited, however, compliance with PPID treatment appears to be poor and it is unclear whether this influences clinical outcome; (viii) evidence is very limited, but horses with clinical signs of PPID are likely to shed more nematode eggs than horses without clinical signs of PPID; it is unclear whether this results in an increased risk of parasitic disease or whether there is a need for more frequent assessment of faecal worm egg counts.MAIN LIMITATIONS:Limited relevant publications in the veterinary scientific literature.CONCLUSIONS:These findings should be used to inform decision-making in equine primary care practice.

Summary Laminitis associated with hyperinsulinaemia is a significant cause of morbidity and mortality in horses with equine metabolic syndrome. The diagnosis and management of hyperinsulinaemia are therefore critical to prevent the development of laminitis. This review article aims to help primary care clinicians manage patients with hyperinsulinaemia by providing an overview of diagnostics, management strategies and new therapies that are available.

Background: Suspensory ligament branch desmitis (SLBD) is a common injury in Thoroughbred racehorses. Orthobiologic treatment of these injuries is a relatively new approach, and there is limited information available on post injury racing performance in racehorses treated with mesenchymal stem cells (MSCs).Objectives: To assess racing performance post injury in Thoroughbred racehorses with SLBD treated with MSCs.Study design: Retrospective case series.Methods: Medical records of racehorses with SLBD treated with MSCs from 2010 to 2019 were reviewed. All horses were treated with allogeneic stem cells injected locally at the time of diagnosis and subsequently received 3-4 treatments with autologous bone-marrow derived MSCs. Ultrasonographic and radiographic images were evaluated to determine the degree of suspensory branch injury and sesamoiditis of the associated proximal sesamoid bone. Race performance was assessed by career length, class of races, number of starts and earnings post injury. Race performance of horses that raced pre and post injury were compared.Results: Of 69 treated horses, 71% (49/69) [95% CI: 59%-81%] raced post injury. Horses that had raced pre injury were more likely to race post injury (90% [18/20]) than horses that did not race pre injury (63% [31/49]; p = 0.03). Females were less likely to race post injury than males (52% [11/21] vs. 79% [38/49], respectively; p = 0.02). In the 18 horses that raced pre and post injury, the number of races, earnings and earnings per start were not significantly different pre and post injury. The average career length of all horses that raced post injury was 29.5 months.Main limitations: Retrospective study design and lack of controls.Conclusions: Treatment with MSCs resulted in a majority of Thoroughbred racehorses with SLBD racing post treatment. Racing pre injury and being male was positively associated with racing post injury.

Summary Development of a subunit vaccine (Strangvac) from fusion of recombinant Streptococcus equi proteins offers a new tool in the management of infection with Streptococcus equi subspecies equi . Experience to date indicates that the vaccine is effective in limiting disease spread, and through inclusion of only the desired proteins needed for induction of an effective immune response, the safety profile appears far better than with previous vaccines. Published reports of the use of the vaccine are limited, and to date, vets have had limited information upon which to make informed decisions on the potential benefits of this novel vaccine. This article was developed to share the collective experience of the authors in using Strangvac and to highlight potential benefits of integrating vaccination alongside biosecurity measures in controlling ‘strangles’. This article reviews the use of vaccination prior to movement, in the face of outbreaks and also discusses use in mares and foals. Safety and the benefits of differentiating vaccinated from infected animals are also discussed. The reader should consider the level of evidence upon which the recommendations are based as it is frequently weak and limited to anecdotal reports or interpretation of unpublished data. The recommendations made are certain to be revised or replaced as new evidence comes forward but provide a basis for practitioners to implement vaccination strategies based on what is known currently. At times, the authors' recommendations deviate from those that were initially put down in the summary of product characteristics. This comes as a result of clinical experience that has been gained since the initial experimental studies were performed prior to registration. Veterinary surgeons using the vaccine outside of the regimen set down in the summary of product characteristics should be cognisant of their local legal framework and should ensure that they have informed consent to do so.

SummaryRecent studies report the use of a range of treatments for equine glandular gastric disease, but with all treatments, refractory disease is common. The evidence for some widely used treatments is very poor. Treatments may aim to suppress acid production (e.g. omeprazole), promote mucosal barrier function (e.g. misoprostol/sucralfate), or both. It is imperative that all treatments are combined with management to minimise known risk factors, primarily physiological and psychological stressors.

BackgroundAn extended-release injectable omeprazole formulation (ERIO) has become a popular treatment for equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD) where it is available; however, published data are limited and optimal treatment regimens have not been determined. ObjectivesTo compare effects of treatment on ESGD and EGGD when an ERIO formulation is administered at either 5- or 7-day intervals. Study designRetrospective clinical study. MethodsCase records and gastroscopy images of horses with ESGD or EGGD treated with ERIO were reviewed. Images were anonymised and graded by one researcher masked to treatment group. Treatment responses were compared between the two treatment schedules using univariable ordered logistic regression. ResultsForty-three horses were treated with ERIO at 5-day intervals and 39 horses at 7-day intervals. Signalment and presenting signs did not differ between groups. The proportions of horses with EGGD healing (to grade 0 or 1) in association with ERIO used at 5-day intervals (93%) were higher than associated with treatment at 7-day intervals (69%; odds ratio [OR]: 2.41, 95% CI: 1.23-4.74, p = 0.01). For ESGD, there was no significant difference in the proportion of horses healing in association with treatment at 5-day intervals (97%) compared with 7-day intervals (82%; OR: 2.75, 95% CI: 0.91-8.31, p = 0.07). Four of 328 injections were associated with an injection-site reaction (1%). Main limitationsRetrospective study design, lack of randomisation and limited case numbers. ConclusionsThe use of ERIO at 5-day intervals might be more appropriate than the 7-day interval that is used currently.

IntroductionDopaminergic agonists are accepted as the most effective treatment for pituitary pars intermedia dysfunction. However, some horses are refractory to daily oral pergolide, the recommended registered treatment. Extended-release cabergoline (ERC) injection may offer an alternative. The objective of this retrospective case series was to describe clinical and endocrinological responses to ERC.MethodsMedical records of horses treated with weekly intramuscular injections of ERC (5 mg/mL, BOVA Aus) at either 0.01 mg/kg (high dose, HD) (n = 10) or 0.005 mg/kg (low dose, LD) (n = 30) were reviewed. Short-term ACTH responses were assessed at 5–8 days using a Wilcoxon signed ranked test. Longer-term ACTH responses (30 to 365 days) were assessed using generalised estimating equations.ResultsFive to eight days after the first dose of LDERC, median adrenocorticotropic hormone (ACTH) concentration was lower (p = 0.001), changing from 153 pg/mL (IQR: 78, 331) to 57 pg/mL (IQR: 30, 102). With HDERC, median ACTH concentration was also 153 pg/mL (IQR: 96, 185) before and then 56 pg/mL (IQR: 29, 86) after 5–8 days of treatment (p = 0.047). Over 12 months of treatment, ACTH concentration ranged from 14 to >1,250 pg/mL (median: 51 pg/mL) in horses treated with LDERC and 20 to 472 pg/mL (median: 50 pg/mL) in horses treated with HDERC. Measurements remained above the seasonal reference range in 39.3 and 52.3% of horses treated with LDERC and HDERC, respectively. Clinical improvement was reported by owners in 78.3 and 100% of horses treated with LDERC and HDERC, respectively. Partial, self-limiting inappetence was reported in 30.0% of LDERC and 60% HDERC cases. Seven horses exhibited lethargy (5 LDERC, 2 HDERC). Insulin concentrations measured 30 days post-ERC treatment were no different from baseline.DiscussionClinical and endocrinological responses were consistent with results of previous reports of oral pergolide treatment. Weekly injection of ERC may be an effective alternative to pergolide; the 0.005 mg/kg dose appeared to be as effective, with less risk of inappetence, than the 0.01 mg/kg dose that has been reported previously.

SummaryBackgroundSodium‐glucose cotransporter 2 inhibitors (SGLT2i) are being used increasingly in equine practice. While there is emerging clinical evidence of the safety and efficacy of these drugs, there are currently no reports to document owner experiences with treatment.ObjectiveThe objective of the study was to report owner experiences and observations following treatment with SGLT2i in horses.Study designA cross‐sectional online survey.MethodsHorse owners were recruited via social media, online forums and their veterinarians to participate in an anonymous online survey to document their experiences and observations when treating their horses with SGLT2i.ResultsThree hundred forty‐two responses met the inclusion criteria. Ertugliflozin was the most commonly prescribed SGLT2i (79.8%), and the most common reasons for treatment were high insulin concentrations (84.2%) and active laminitis (59.7%). 85.3% of owners reported their horses had an improved quality of life after commencing treatment, while 9.4% reported no change and 5.3% reported a worsening of clinical signs. Of owners who had considered euthanasia prior to treatment (n = 77), 80.5% reported their horse's level of pain to be either mild or absent after 30 days of treatment and 94.8% reported their horse's quality of life to be improved. Most owners (n = 220, 64.7%) reported they were either extremely satisfied or somewhat satisfied (n = 72, 21.2%) with treatment. Treatment concerns included safety/side effects, medication cost, availability and long‐term efficacy. 114 owners (33.3%) reported one or more initial adverse effects upon induction onto the medication, particularly excessive urination (n = 70, 20.5%), excessive drinking (n = 38, 11.1%), excessive weight loss (n = 34, 9.9%) and dullness (n = 26, 7.6%).Main limitationSampling bias through social media and veterinary practices and reliance on subjective owner reports.ConclusionThe use of SGLT2i in horses was associated with excellent rates of owner satisfaction and owner‐reported improved quality of life for the horse; however, some adverse effects were observed.

Summary Background Hyperinsulinaemia‐associated laminitis (HAL) is encountered commonly in equine practice. There are currently no registered medications which specifically target hyperinsulinaemia in horses and ponies. Sodium–glucose cotransporter 2 inhibitors (SGLT2i) have been demonstrated to limit post‐prandial insulin responses and prevent the development of diet‐induced laminitis. Objectives The objective of the study was to evaluate the efficacy of an SGLT2i, ertugliflozin, in the management of hyperinsulinaemia and laminitis. Study design Retrospective case series. Methods Medical records of 51 horses and ponies that had presented with laminitis and hyperinsulinaemia and had been treated with oral ertugliflozin at 0.05 mg/kg once daily for a minimum of 30 days were reviewed. Results After 30 days of treatment with ertugliflozin, there was a reduction in insulin concentrations from a median of >300 μu/ml (IQR: 149, >300) to 43 μu/ml (IQR: 20, 66) ( p < 0.001). Modified Obel laminitis scores improved, reducing from a median of 10/12 to 1/12 ( p < 0.001). Median serum triglyceride concentrations increased from 0.6 (IQR: 0.4, 0.9) before treatment to 1.4 (IQR: 0.8, 3.7) mmol/L after 30 days of treatment ( p < 0.001) before declining, however, none of the horses developed any clinical signs of hyperlipaemia. Ten horses (19%) were reported to have polyuria and polydipsia during treatment, otherwise no adverse clinical effects were identified. Main limitations The study was limited by the absence of a control group, the retrospective data collection and the short period of follow‐up. Conclusions Ertugliflozin may be effective in reducing insulin concentrations in horses and ponies with equine metabolic syndrome and its use may hasten recovery from laminitis associated with hyperinsulinaemia.

UK-Vet EquineVol. 7, No. 1 RoundtableFree AccessHow do we prevent and control future outbreaks of equine herpesvirus myeloencephalopathy at equestrian gatherings?David Rendle, Anne Couroucé, Lutz Goehring, Jenny Hall, Philip Ivens, Celia Marr, Richard Newton, Klaus OsterriederDavid RendleSearch for more papers by this author, Anne CouroucéSearch for more papers by this author, Lutz GoehringSearch for more papers by this author, Jenny HallSearch for more papers by this author, Philip IvensSearch for more papers by this author, Celia MarrSearch for more papers by this author, Richard NewtonSearch for more papers by this author, Klaus OsterriederSearch for more papers by this authorDavid Rendle; Anne Couroucé; Lutz Goehring; Jenny Hall; Philip Ivens; Celia Marr; Richard Newton; Klaus OsterriederPublished Online:30 Jan 2023https://doi.org/10.12968/ukve.2023.7.1.21AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareShare onFacebookTwitterLinked InEmail David RendleAnne CouroucéLutz GoehringJenny HallPhilip IvensCelia MarrRichard NewtonKlaus OsterriederForewordThis document was commissioned by UK-Vet Equine to provide veterinary surgeons with up-to-date information on equine herpesvirus myeloencephalopathy in the wake of the outbreaks that occurred in Valencia and subsequently across Europe and the Middle East in 2021. The content of the document and practical recommendations were developed from discussion between the authors, considering published and unpublished research relating to EHV using a roundtable forum and online discussion. Where research evidence was conflicting or absent, collective expert opinion of the group was applied. The opinions expressed are the consensus of views expressed by the authors who all approved the final manuscript. Where an agreement was not reached, diverging views are presented. The expert group was organised by UK-Vet Equine and the meeting held online on 10th June 2022 with sponsorship from Zoetis. The sponsors were not involved in the production of the manuscript.Why should we be concerned about equine herpesvirus myeloencephalopathy?There are nine different equid herpesviruses (EHVs); five types (EHV-1 to EHV-5) infect the domestic horse and four, EHV-6 to EHV-9, are associated with infections in wild equids and other perissodactyl including asses, zebra and rhinoceros. The alpha herpesviruses EHV-1 and EHV-4 are respiratory pathogens, and EHV-1 also has the potential to cause outbreaks of abortion and neurological disease. EHV-1 is a highly successful host-adapted equine pathogen with a complex life cycle that enables its spread and persistence within the global horse population. It is believed that there is early and widespread infection of youngstock which, combined with persistent infection coupled with recrudescence (latency and reactivation), ensures endemicity and the somewhat unpredictable manifestation of clinical disease in the UK and globally. The spread and persistence of the virus is not dependent on clinical disease and silent transmission is common, allowing transmission down equine generations and persistence within herds.Outbreaks of equine herpesvirus myeloencephalopathy (EHM) can have high rates of morbidity and mortality (Henninger et al, 2007; Pusterla et al, 2010) and treatment is often unsuccesful in severe cases. Within a stabled population, rates of infection and neurological disease may be as high as 80% and 40% respectively (Henninger et al, 2007). Any horse can be a latent carrier (Figure 1), so all horse movements carry a risk of triggering reactivation and nasal shedding of virus, although the overall risk of reactivation and recrudescence from latency with subsequent transmission appears to be low. The occurrence of clinical outbreaks is sporadic and unpredictable, and all horses are vulnerable to disease. Outbreaks of EHM have resulted in the cancellation of gatherings, placing restrictions on horses and forcing the closure of some equine hospitals (Vandenberghe et al, 2021), with associated economic consequences. Veterinary surgeons, organisers of equestrian gatherings and horse owners have a shared responsibility to minimise the risk of EHV-related disease, while recognising that the risk can never be eliminated. EHM is reportable or notifiable in many countries, although not the UK.Figure 1. Equine herpesvirus-1 (EHV-1) persists in the host and thus disseminates between the equine generations by establishing viral latency and subsequent reactivation (courtesy of Professor George Allen, Gluck Equine Research Centre).Aetiopathogenesis of equine herpesvirus myeloencephalopathyThe virus rapidly enters respiratory epithelial cells and readily infects cells of the local lymphoid tissues, such as monocytes and lymphocytes in the upper respiratory tract, with infected leucocytes ultimately establishing a cell-associated viraemia (starting as early as day 3 post-infection), disseminating the virus to sites of secondary replication including the endothelium of small blood vessels within the spinal cord and/or the uterus of a pregnantmare. Endothelial cell infection results in cell extravasation, vasculitis and thrombus formation, which results in hypoxia and subsequent axon swelling as well as haemorrhage, with the extent and location of the neurological lesions determining the nature and severity of clinical signs (Table 1). Longer motor neuron pathways are more likely to be affected, which explains why the symptoms of hindlimb ataxia and inability to open the bladder to urinate (with resultant overflow incontinence) are the most frequently reported clinical signs.Table 1. Clinical signs which may develop in association with equine herpesvirus myeloencephalopathyAnatomical areaClinical signLimbsTemporary ataxia and paresis which may or may not progress to quadriplegiaDragging toes of hind limbs when moving on a figure of eight Hindlimb incoordinationBladder sphincter dysfunctionDysuria and inability to pass urineCranial nerve signs (uncommon)Head tilt, nystagmus, facial twitchingTable 1. Clinical signs which may develop in association with equine herpesvirus myeloencephalopathyView as image HTML In young, naïve horses, EHV-1 usually causes a biphasic pyrexia (Figure 2), but these temperature increases are rarely detected unless routine temperature monitoring is under-taken. In older horses with more robust immunity, the initial phase of infection may not be evident clinically, and pyrexia may not develop until there is viraemia around 3–5 days post-infection. Therefore, viral shedding and disease transmission can occur before there is clinical evidence of infection. The severity of clinical signs is unpredictable in individual animals, but is the consequence of a complex combination of the virulence of the virus strain, host genetics, infectious dose, level of cell-associated viraemia, degree of ischaemia and consequent pathology, host immunity and degree of immune response. Increasing age also appears to be a risk factor for EHM (Henninger et al, 2007).Figure 2. Schematic outlining the approximate timeline of clinical signs, virus shedding and cell-associated viraemia following experimental infection of ponies on day 0 (courtesy of Dr Julia Kydd).Risk factors for equine herpesvirus-1 infectionEHV-1 typically spreads slowly within a population, although the spread can be more rapid if infected horses with respiratory signs are in close contact and there is greater potential for smear infection or direct transmission. Airborne spread will occur over distances of a few metres, with the risk increasing if horses are coughing and sneezing. However, these signs may not always be evident. Indirect spread may occur via people and fomites, for example with the use of shared equipment or tack. The risk of infection will also be increased by:Absence of precautions taken when introducing or mixing horsesMixing horses from different sources, particularly young horsesMixing horses that have been subject to recent stressors, such as transportationHaving large numbers of horses in a shared airspacePoor ventilationSharing of equipment, especially tack, without appropriate cleaning and disinfectionHuman contact with multiple horses from different sources, without appropriate sanitary measures.Where several of these risk factors occur concurrently, the risk of infection increases proportionally (Traub-Dargatz et al, 2013).Recent historical perspectivesIn February 2021, an EHV-1 outbreak associated with a high proportion of horses suffering from EHM occurred in Valencia, Spain at a large show-jumping competition, resulting in the reported deaths of 18 horses in mainland Europe over a 4-week period and 31 related EHV-1 outbreaks across 10 countries: Belgium, Denmark, France, Germany, Italy, Qatar, Spain, Slovakia, Sweden and Switzerland. The full report of the outbreak produced by the International Federation for Equestrian Sports (FEI) is available at https://inside.fei.org/fei/your-role/veterinarians/biosecurity-move-ments/biosecurity/ehv-1/report. All international FEI events were cancelled in continental Europe from 1 March to 11 April, including the World Cup Finals, and 3836 horses in the FEI database were blocked from further competition until they had fulfilled the FEI's health requirements to demonstrate freedom from infection.The virus was subsequently identified to be A2254/N752 genotype, a strain which commonly circulates in Europe and would not normally be considered particularly pathogenic. Specifically, the virus identified did not have the G2254/D752 nucleotide/amino acid substitution in the DNA polymerase that had previously been shown to be associated with a higher risk of neurological disease. Between the end of January and 21st February, over 700 horses passed through the Valencia event, with many of the horses spending several weeks on site. Many of the horses attending the event had travelled for days to reach the event. The outbreak started in temporary tented stables that had closed sides, limited ventilation, and contained over 400 horses housed in rows of 20 with 3.5m wide aisles between rows (Figure 3).Figure 3. External and internal views of the temporary tented stabling at the 2021 Valencia event, in which a major outbreak of equine herpesvirus occurred. A total of 20 rows of 20 horses were housed with a 3.5m aisle between rows. Having such a large number of horses in such close proximity within the same airspace was thought to be a major factor in the spread of equine herpesvirus.The limited ventilation and high number of horses within the airspace may have led to extremely high levels of virus circulation, meaning immunity, if present, was overcome. The location of horses within the stables was found to be associated with a higher risk of infection. Horses that were outside the stabling or on the periphery facing out were six times less likely to develop pyrexia and nine times less likely to develop neurological signs (Couroucé, unpublished data).Recommendations for the protection of competition horsesThe FEI conducted a comprehensive and fully transparent investigation into every aspect of the EHM outbreak that occurred in Valencia in 2021 (Termine et al, 2001) and their three part report is available on the FEI website (FEI, 2022).Part 1 provides a comprehensive and factual description of the outbreak, including the series of events, causes, roles and responsibilities, and analysis. It evaluates what was done correctly and identifies where there were failings, and the lessons learnedPart 2 covers the measures implemented to allow return to competition following the 6-week FEI-imposed lockdown on international sport in mainland EuropePart 3 looks at the way forward, including potential global vaccination protocols.Other resources offer advice on minimising the risk of EHV-1 transmission:National Trainers Federation codes of practice: https://www.racehorsetrainers.org/publications/pdfs/cop.pdfHorserace Betting Levy Board codes of practice: https://codes.hblb.org.uk/index.php/page/32, which is also available via the EquiBioSafe App (https://itunes.apple.com/gb/app/equibiosafe/id1131137694)American Association of Equine Practitioners and US Department of Agriculture guidance: https://aaep.org/guidelines/infectious-disease-control/equine-herpesvirus-resourcesBritish Equestrian Equine Infectious Disease Advisory Group notes: https://www.britishequestrian.org.uk/equine/health-biosecurity/advice-notes-for-equine-gatherings (Box 2)FEI horse health requirements: https://inside.fei.org/fei/your-role/veterinarians/biosecurity-movements/horse-healthMeasures implemented by the International Federation for Equine Sport following the Valencia outbreakIn the wake of the Valencia outbreak the FEI introduced measures that, in the short term, aimed to minimise the risks of further propagating the spread of EHV-1 infections associated with the restart of FEI competitions in continental Europe and, in the long term, aim to increase biosecurity knowledge, skills and awareness among all FEI stakeholders in order to prevent future EHV-1 outbreaks:Tour venues were risk-assessed and biosecurity protocols for events reviewedForeign veterinary delegates, appointed by the FEI, will attend high-risk eventsFEI jurisdiction during and after events was extended so that it has greater powers to implement disease control measuresThe FEI recommended that National Federations extended their jurisdictions to ensure they had the authority to shut down events should it be necessary to do so.The FEI HorseApp that had already been in development was brought into operation to enable recording of:Examination findings on arrival at venuesRecording of rectal temperatures before and during an FEI eventDigital submission of the FEI equine health self-certification formPCR test resultsEquine whereabouts informationThe procedure for veterinary examination of horses at the entry to events was bolstered by the introduction of the HorseApp, as this provided a clear evidence trail for examination having been carried out on arrival. Mandatory recording of entry examination findings in the FEI HorseApp by an FEI veterinarian was required, alongside GPS location of the horse's microchip.Twice daily temperature monitoring became mandatory at FEI competition from April 2021 and is facilitated by the FEI HorseApp in which recordings must be entered.The protocols for management of suspected cases and the resourcing of isolation stables at events have been enhanced. Access to laboratories with PCR equipment is limited, particularly on weekends, and the FEI has urged the development of stable-side PCR tests for EHV-1 that can be used systematically at competition venues.The FEI also highlighted a need to fund an Emergency Response Unit that could be deployed to support any National Federation immediately if a disease outbreak is confirmed at an FEI Event. The unit will include veterinary surgeons with expertise in the diagnosis and treatment of infectious diseases. In the UK, the British Equine Federation's emergency response group (BEFERG) is on stand-by to lead decision-making in the event of an outbreak.Article 1018 of the 2020 FEI Veterinary Regulations already requires that organising committees:Develop a biosecurity plan for all eventsMaintain records of where horses have been kept in stablesMake contingency plans and determine adequate provision for isolation facilitiesPost-Valencia, the FEI has highlighted the importance of:Having mitigation plans for outbreaks of infectious disease at all eventsAccessing PCR testing for EHV-1 for horses arriving at designated eventsMinimising nose-to-nose contact through the use of partitions that are at least 2.4m high, implementing one-way movement of horses through venues and preventing horses from lingering in aisles during preparation, grooming and mucking outApplying basic hygiene procedures such as regular hand washing and cleaning of footwear and equipmentControlling dogs at events.Box 1. Recommendations made by the British Equestrian Federation's equine infectious disease advisory group for the prevention of spread of equine herpesvirus at equestrian eventsMeasures should be implemented to prevent the entry of:Any horse with a recent cough, nasal discharge of unknown cause, enlarged lymph nodes or a feverAny horse which is known or under investigation for equine herpesvirus infection (whether associated with respiratory or neurological signs).Any horse which has been in contact with, or lives on the same premises as, a horse known to have or be under investigation for equine herpesvirus infection associated with neurological signs.Where a horse has been excluded due to neurological EHV or neurological EHV-contact, future admission should require that:EITHER all horses on the property have close clinical monitoring with twice daily temperature recording and the excluded status should apply until all horses on the premises have been free of clinical signs for at least 28 days.OR a detailed veterinary report should be presented to the BEF-MB EID veterinarian including robust laboratory evidence to show that the horse intended for admission to a gathering has not been infected with neurological EHVEIDAG suggests this is implemented via a “health and freedom from disease & contact” declaration. The BEF-MB's EID veterinarian should be available to support attending veterinary surgeons if required.Should equine herpesvirus-1/4 vaccination be mandatory for horses attending events?In the UK, inactivated EHV-1 and -4 vaccines are registered for ‘active immunisation of horses to reduce clinical signs due to infection with EHV-1 and 4 and to reduce abortion caused by EHV-1 infection’ and have been shown to reduce the incidence of abortion and virus shedding (Hannant et al, 1993; Goehring et al, 2010; Walle et al, 2010; Heldens et al, 2001; Schabel et al, 2019). Vaccination reduces the number of horses which develop viraemia and shed the virus (Heldens et al, 2001). Therefore, use of vaccines may lead to a reduction in virus circulation in the population and this, in turn, may reduce the risk of EHM both at an individual and herd level. However, there are no robust data that vaccination reduces the risk of EHM and appropriate studies have not been performed, largely owing to the absence of a relevant experimental equine model of this disease syndrome until relatively recently. A systematic review and meta-analysis of the efficacy of commercial or candidate vaccines against EHV-1 in randomised controlled trials (RCTs) was performed recently (Marenzoni et al, 2022). Meta-analysis of 16 eligible RCTs reported in eight studies concluded that EHV-1 vaccination generally resulted in a slight improvement of clinical and virological outcomes, although not to a significant extent (Marenzoni et al, 2022).The case for vaccination in the control and prevention of EHM is equivocal, as analyses of some previous outbreaks have demonstrated a significant association between the use of EHV vaccination among outbreak populations and greater frequency of EHM (Traub-Dargatz et al, 2013). Unpublished data from 157 horses that remained at the venue during the Valencia outbreak showed that, compared to non-vaccinated horses, horses that were vaccinated were more likely to die (12% vs 3%; P=0.036), more likely to develop EHM (23% vs 11%; P=0.04) and more likely to develop EHM and/or fever (88% vs 60%; P=0.001) However, there was no significant corresponding difference in EHV-1 infection prevalence (by PCR) between these groups (49% vs 48%; P=0.95) (Cunilleras, 2021). Although, it is cautioned that this should not be assumed to be a causal association as there needs to be appropriate consideration of confounding factors, such as age and spatial or temporal clustering of horses within enclosed airspaces, leading to marked variation in load and duration of viral exposure. Most of the participants in this roundtable consider that the use of a vaccine containing an inactivated EHV-1 strain following exposure does not increase the risk of clinical neurological disease, and anecdotally, some horses were reported to have been vaccinated in the face of potential exposure in Valencia with no apparent increase in frequency of EHM.While with the currently available products, vaccination in horses that have potentially been exposed to EHV-1 is generally not considered to be contraindicated, some of the authors do not consider it to be beneficial for practical reasons, such as:Time taken to stimulate immune protectionA false sense of protection from the risk of EHM and EHV-1 infection, with the risk of lapses in maintaining biosecurity measuresInterference with serological assay interpretation complicating the use of these tests to aid outbreak clearanceVaccines have not been registered for this indicationTheoretical possibility of such use of EHV-1 vaccine-triggering clinical disease, although this has never been reported in practice and, in the view of some of our expert panel, is unlikely with a vaccine containing an inactivated viral strain.In France, mandatory EHV-1 vaccination was introduced for broodmares in 2015, Thoroughbred racehorses in 2018 and for Standardbreds in 2019. Mandatory vaccination was imposed by the US Equestrian Federation in 2018, and the German Equestrian Sports Federation is set to impose mandatory vaccination for horses competing under their rules. The Société Hippique Française has imposed mandatory vaccination for horses up to 3 years of age.The FEI has currently stopped short of mandating compulsory vaccination for horses competing under their rules and are keeping the situation under review. A particular challenge to implementing mandatory vaccination by a global regulator like the FEI is ensuring the availability and consistency of vaccine supplies across different countries; 20 FEI member national federations reported an absence of registered vaccines, 33 of 73 reported periodic interruptions in vaccine availability, and in two countries, vaccination is reported to be prevented by legal restrictions.The British Equestrian Federation does not mandate EHV-1 vaccination, but recommends that the following groups of horses be re-vaccinated against EHV-1 or -4 at 6-month intervals in accordance with the manufacturers' recommendations (https://www.britishe-questrian.org.uk/equine/health-biosecurity/advice-notes-for-equine-gatherings):Horses less than 5 years of age (but older than 6 months)Horses that may come into contact with pregnant maresHorses housed at facilities with frequent movement of horses on and off the premisesHorses that frequently attend gatherings where horses mingle in close proximity.For EHV-1 or -4 vaccination to be effective, booster doses are required at 6-month intervals. In some populations, vaccines are being used ‘off-label’ (and without proof of efficacy) as frequently as every 2 months, with booster vaccinations of all in-contact and at-risk horses being performed in the event of EHV-1-related disease (Goehring, personal communication).Research into new vaccines that may offer greater protection is required; however, vaccination will never provide complete protection from disease. Herpesviruses are adept at evading host immunity through multiple immuneescape molecules they encode and through latency. Hence, infection does not result in long-lasting natural immunity. Therefore, it is unlikely that it will be possible to achieve the level of herd immunity that is theoretically possible with vaccination for some other diseases. Vaccination will not eliminate the need for effective biosecurity and other disease control measures. While there is a risk that vaccination may result in complacency with respect to the need for additional biosecurity measures, it may alternatively reinforce the need for compliance with other infectious disease control measures.Additional recommendationsLarge equestrian gatherings over multiple days pose an increased risk of EHV-1 outbreaks, and there is then a high likelihood of further outbreaks at connected equestrian competition venues if additional measures are not put into place. Anecdotally, the number of reported EHV-1 and EHM cases appears to be increasing, which raises concerns that infections are becoming more common because of greater numbers of horse movements over increasing distances, although this may also be linked to enhanced investigations with improved diagnostics and online reporting.There is a trend of increased prevalence in larger equestrian facilities and events with greater numbers of horses housed on the same premises. If further outbreaks, such as Valencia 2021, are to be prevented, then consideration needs to be given to additional measures that can be implemented before, during and after competition to reduce the risk of infectious transmission on and away from event sites to home premises and other event venues (Figure 4). Many of these measures have already been implemented, or are under consideration by the FEI, and the introduction of the FEI HorseApp is a major step forward.Figure 4. Schematic of equine herpesvirus (EHV)-1 transmission pathways onto, within and off site at equestrian gatherings.Critical control points for equine herpesvirus myeloen-cephalopathy preventionPre competition – horsesAdditional measures can be implemented to reduce the risk of horses with clinical or subclinical EHV-1 infection attending equestrian gatherings. Placing a responsibility on competitors to declare that their horses have been free from clinical signs (and have been free from contact with horses with clinical signs) should help to prevent horses at high risk of transmitting EHV-1 from travelling, and would serve as a reminder to competitors of the risks of infectious disease transmission at competitions. Caretakers should be encouraged to vaccinate their horses strategically to ensure that levels of immunity are likely to be high at the time of travelling and competing.Pre-competition – facilityThe FEI report on the Valencia outbreak high-lighted potential inadequacies in the procedures for veterinary inspection of horses on arrival at events (FEI, 2022). Where possible, veterinary inspection of all horses, including assessment of rectal temperature, should take place before admission to the competition venue. To be effective, there must also be a workable plan for how to deal with any horse arriving at a venue with a fever, in a manner which ensures it can receive appropriate veterinary care without endangering others. The site of inspection, and associated isolation facilities, should be separate from the main competition venue.Limiting the number of horses and maximising the ventilation within each airspace in the event venue will limit the risk of disease transmission. More guidance should be provided to event organisers on the requirements for stabling at competition venues, with equine biosecurity and welfare being prioritised over other considerations.Every competition venue should have a contingency plan for each event that considers the levels of risk and makes provisions for managing disease outbreaks accordingly.Horse monitoring during competitionIt is recognised that compliance with recommendations or requirements for manual temperature taking is very poor and is unlikely to improve whatever measures or regulations are put in place. There is a compelling argument for the use of temperature monitoring microchips that can be used to collect individual horse temperature data either by athletes or veterinary officials. If all horses were required to have temperature monitoring microchips or use wearable temperature monitors, every horse at a venue could be checked very quickly with the data constantly monitored. Time would also be saved at entry inspections, as these devices would generate a continuous temperature diary which could be reviewed retrospectively if necessary.Isolation facilities and protocolsIsolation facilities are rarely adequate at competition venues and thus need greater consideration. The recommendation in the FEI Veterinary Regulations is the provision of two isolation stables, with an additional one for every 100 horses and a contingency for over-flow isolation facilities.Depending on the size and level of risk at the event, isolation facilities may need to allow multiple different groups of horses to be isolated from one another. The number of isolation stables required should be dictated by the size of the event and may be reduced if other biosecurity measures (such as vaccination, athlete declarations, veterinary inspections on arrival, remote digital temperature monitoring and appropriately designed stabling) are implemented appropriately.Isolation stabling would not need to be permanent, but there needs to be a contingency for prompt referral of horses and samples to appropriately equipped veterinary hospitals and laboratories, respectively, and potentially for the rapid erection of extra temporary stabling should the need arise.Verifying freedom from infection after EHM outbreaksFurther consideration needs to be given to the requirements for verifying freedom from EHV-1 infection and to aligning protocols across different organisations and events, where this is to be adopted. Repeated negative test results (PCR and paired serology testing) are considered to provide robust evidence of freedom from infection (Gonzalez-Medina and Newton, 2015). However, in the Valencia outbreak, some horses returned negative PCR results before subsequently becoming positive. The cycle threshold value for any PCR result is important, as is knowledge of the biosecurity measures that are in place to minimise the possib

Laminitis associated with hyperinsulinemia a significant cause of morbidity and mortality in horses with equine metabolic syndrome. The diagnosis and management of insulin dysregulation are therefore critical to prevent the development of hyperinsulinemia-associated laminitis. This review article aims to help primary care clinicians manage patients with insulin dysregulation by providing an overview of diagnostics, management strategies and new therapies that are available.

BACKGROUND:Oral omeprazole is the accepted treatment for equine squamous gastric disease (ESGD); however, it is not universally effective. Esomeprazole results in more consistent and pronounced acid suppression in men and is more effective than omeprazole in the treatment of oesophageal and gastric disease. Pharmacodynamic and pilot clinical studies have indicated esomeprazole might also be more effective than omeprazole in horses. OBJECTIVES:To compare the efficacy and safety of oral esomeprazole and omeprazole pastes in the treatment of ESGD and, where present, concurrent equine glandular gastric disease (EGGD). STUDY DESIGN:Randomised, single-blinded controlled trial. METHODS:Horses presenting with grade ≥2 ESGD lesions were randomly allocated to receive 4 mg/kg of either a buffered esomeprazole or omeprazole paste orally once daily for 28 days before gastroscopy being repeated within a further 3 days. Videos and images were anonymised and subsequently graded blind by one researcher. The severity of ESGD (and EGGD) lesions before and after treatment, and thereby treatment responses, were compared using univariable logistic regression. RESULTS:A higher proportion of horses had ESGD healing in response to esomeprazole treatment (63/74, 85%) than with omeprazole treatment (43/73, 59%) (odds ratio [OR]: 4.00, 95% confidence interval [CI]: 1.81, 8.82, p = 0.001). In a subset of horses that had concurrent EGGD, a greater proportion of the horses treated with esomeprazole had lesions ≤grade 1 (esomeprazole 28/51, 55%; omeprazole 6/24, 25%; OR: 3.65, 95% CI: 1.25, 10.71, p = 0.02) Using grade 0 as the benchmark for EGGD healing, the difference remained significant (OR: 4.44, 95% CI: 1.33, 14.85, p = 0.02). MAIN LIMITATIONS:It may not be possible to extrapolate these results to other populations with different signalment or management. CONCLUSIONS:Oral-buffered esomeprazole was a more effective treatment for ESGD (and concurrent EGGD) than oral-buffered omeprazole.