128 GoFiguR: A web-based app for creating and modifying figures

Journal of Clinical and Translational Science · 2026-04-01

Objectives/Goals: The goal was to create and deploy an intuitive, easy-to-use tool that clinical investigators can use to make or modify high-quality figures for publication. Methods/Study Population: We developed GoFiguR, an interactive application built with RShiny, to help researchers and analysts visualize their data with ease. Users upload data files, choose a plot type (histogram, scatterplot, boxplot, bar plot, or Kaplan-Meier curve), and then specify variables, labels, and font sizes to generate the figure. Alternatively, users can upload a ggplot2 object to modify labels, font sizes, or plot themes in an existing figure. All figures can be exported either as ggplot2 object for additional modification or as one of multiple file formats with user-defined dimensions and resolution. GoFiguR is hosted on a secure, university-maintained website with access limited to university personnel. Instructional step-by-step handouts were developed to assist investigators in the use of the app. Results/Anticipated Results: We plan to integrate GoFiguR into the biostatistics consultative services offered by our Clinical and Translational Science Program. In practice, we anticipate several use cases: investigators and analysts can use GoFiguR to generate mock figures during project planning, analysts can create visualizations following data analysis, and investigators can apply final edits to figures prior to dissemination. Through this collaborative process, investigators are expected to gain a deeper understanding of appropriate figure types for various data visualizations. Discussion/Significance of Impact: Creating publication-quality figures is often a time-intensive process requiring multiple iterations, between the investigator and analyst. GoFiguR enables more efficient development of figures as investigators can directly modify figures to their specification.

The Systemic Inflammatory Response Syndrome and Predictors of Infection and Mortality in 1068 Critically Ill Newborn Foals

Journal of Veterinary Internal Medicine · 2025-03-01 · 5 citations

BACKGROUND: Sepsis has been defined in humans as the concurrent proven or suspected presence of microbial infection and the systemic inflammatory response syndrome (SIRS). Sepsis is the leading cause of morbidity and mortality in neonatal foals. The clinical utility of using SIRS or its individual components to predict infection and mortality in critically ill foals is currently unknown. OBJECTIVES: Assess the ability of history and signalment, clinical findings, laboratory results, and SIRS-related indices to predict infection and mortality in critically ill foals. ANIMALS: Retrospective, multi-center, cross-sectional study using a convenience sample of 1068 critically ill foals < 3 days of age admitted to 16 veterinary referral hospitals in 4 countries. METHODS: Data were retrieved from medical records. Infection was defined as the presence of bacteremia (positive blood culture) or clinical identification of an infected focus on admission. Univariate non-parametric and categorical methods, multivariate logistic regression, and classification tree methods were used for statistical analysis. RESULTS: Foal age at admission and presence of toxic neutrophils were independent predictors of infection, whereas SIRS-related indices were not predictive of infection. In-hospital mortality was 24%. Independent predictors for mortality were hypokinetic pulses, cold extremities, presence of seizures, blood L-lactate concentration > 6.0 mmol/L, and increased serum potassium and total bilirubin concentrations. CONCLUSIONS AND CLINICAL IMPORTANCE: The presence of infection in critically ill newborn foals was not predicted by SIRS indices. Cardiovascular dysfunction was strongly associated with mortality, suggesting that maintaining adequate perfusion and pulse pressure should be important treatment goals.

Women's experiences of learning of the involvement of a partner possessing child abuse material

RMIT Research Repository (RMIT University Library) · 2024-01-01

This report presents the executive summary and recommendations from a pilot study exploring women's experiences of learning that their partner possessed child abuse material. Nine Australian women were interviewed, regarding how the offence was detected, their partners' initial reactions, the women's initial reactions, police responses, sentencing, impact on the family and relationships, reactions of friends, and the women's feelings of stigma, shame, and lack of support. Although this was a small scale study, the authors are confident in their concluding recommendations for research, policy and practice.

Persistence of Sarcocystis Neurona and Histologic Lesions in Horses with Equine Protozoal Myeloencephalitis (Epm)

SSRN Electronic Journal · 2024-01-01 · 1 citations

Effects of intravenous administration of ascorbic acid (vitamin C) on oxidative status in healthy adult horses

Journal of Veterinary Internal Medicine · 2023-11-10 · 4 citations

BACKGROUND: Ascorbic acid (AA) is an antioxidant that might be beneficial for adjunctive treatment of sepsis in horses. The optimal dose and effects on oxidative status are unknown. HYPOTHESIS: Ascorbic acid administration will increase plasma AA concentrations and decrease determinants of reactive oxygen metabolites (dROM), basal and stimulant-induced intraerythrocytic reactive oxygen species (ROS) concentrations, and stimulant-induced neutrophil ROS production, and increase plasma antioxidant capacity (PAC) in a dose-dependent manner. ANIMALS: Eight healthy horses. METHODS: Randomized placebo-controlled crossover study. Each horse received 4 single-dose IV treatments including AA at 25, 50, and 100 mg/kg and saline (placebo) with each treatment separated by ≥1 week. Blood was collected at baseline, 2 and 6 hours for assessment of plasma dROM and PAC via photometer, intraerythrocytic ROS by flow cytometry, and stimulant-induced neutrophil ROS by a fluorometric assay. Plasma AA concentrations were measured by high-performance liquid chromatography/electrochemical detection. RESULTS: Ascorbic acid at 100 mg/kg resulted in decreased dROM 2 hours after treatment (P = .03, 95% CI 5.51-121.2, point estimate 63.3). There was no effect of AA on basal or stimulant-induced intraerythrocytic ROS (P = .88, 95% CI -0.156 to 0.081, point estimate -0.037; P = .93, 95% CI -0.123 to 0.112, point estimate -0.006, respectively), basal or stimulant-induced neutrophil ROS (P ≥ .12, 95% CI -644.9 to 56.2, point estimate -294.4), or PAC (P ≥ .64, 95% CI -1567 to 463.4, point estimate -552.0) at any dose or timepoint. Plasma AA concentrations increased in a dose-dependent manner. CONCLUSIONS AND CLINICAL IMPORTANCE: High-dose administration of AA might provide antioxidant benefits in horses.

TLR4 and MD2 variation among horses with differential TNFα baseline concentrations and response to intravenous lipopolysaccharide infusion

Scientific Reports · 2023-01-27 · 4 citations

Gram-negative bacterial septicemia is mediated through binding of lipopolysaccharide (LPS) to mammalian toll-like receptor protein 4 (TLR4). TLR4 and its cognate protein, myeloid differentiation factor 2 (MD2) form a heterodimeric complex after binding LPS. This complex induces a cascade of reactions that results in increased proinflammatory cytokine gene expression, including TNFα, which leads to activation of innate immunity. In horses, the immune response to LPS varies widely. To determine if this variation is due to differences in TLR4 or MD2, DNA from 15 healthy adult horses with different TNFα dynamics after experimental intravenous LPS infusion was sequenced across exons of TLR4 and MD2. Haplotypes were constructed for both genes using all identified variants. Four haplotypes were observed for each gene. No significant associations were found between either TNFα baseline concentrations or response to LPS and haplotype; however, there was a significant association (P value = 0.0460) between the baseline TNFα concentration and one MD2 missense variant. Three-dimensional structures of the equine TLR4-MD2-LPS complex were built according to haplotype combinations observed in the study horses, and the implications of missense variants on LPS binding were modeled. Although the sample size was small, there was no evidence that variation in TLR4 or MD2 explains the variability in TNFα response observed after LPS exposure in horses.

ACVIM-Endorsed Statements: Consensus statements, evidence-based practice guidelines and systematic reviews

Journal of Veterinary Internal Medicine · 2023-10-03 · 4 citations

The American College of Veterinary Internal Medicine (ACVIM) has commissioned groups of experts to produce “Consensus Statements” since 2000 to provide veterinarians with information about topics important to ACVIM Diplomates and the veterinary profession. The ACVIM Consensus Statements have been relatively succinct statements intended to guide decision-making about diagnosis, management or treatment of diseases of animals. During the past 20 years, Consensus Statements have evolved and several versions of guidelines have been developed by the ACVIM Board of Regents (BoR) and staff to facilitate selection of the topics, identify panel members, and determine logistics related to format and dissemination of the statements. The general purpose of these guidelines has been to clarify the responsibilities of the Chair and members of the panel, define the length of the statement, set timelines, and establish a financial agreement with panelists. Little attempt has been made to define how ACVIM Consensus Statements are prepared and the manner in which they consider the relevant literature and evaluate and report on evidence. The medical and veterinary communities increasingly rely on evidence-based statements on a particular topic for guidance and counsel on decisions relating to management of diseases.1, 2 There are several conventional formats for these statements, including consensus statements, practice guidelines, systematic reviews and position statements.3-8 Recently, scoping reviews have become more common and are gaining some traction in the veterinary literature.9 The methodology underlying each of these types of statements differs, but what all have in common is a well-described and accepted methodology for objectively considering and reporting the amount and quality of evidence. For example, the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach is now widely used for developing practice (and other) guidelines, Cochrane prescribes a particular methodology for undertaking evidence-based reviews, Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) defines how systematic reviews should be carried out, and the Delphi method is widely accepted for development of consensus statements.4, 5, 7, 8, 10-15 Scoping reviews are not designed or intended to produce a critically appraised and synthesized result/answer to a particular question and are therefore not included as an ACVIM-Endorsed Statement (AES).9 Narrative reviews are common in both the human and veterinary medical literature and there is a proposed methodology for evaluating their quality,16 but they are not considered sufficient to provide a rigorous, evidence-based assessment of a topic.17 Narrative reviews are not listed in the Oxford Centre for Evidence-Based Medicine hierarchy of evidence.17 There is increasing recognition of the need for clear guidelines for the development of expert statements.1 The variety of formats for these evidence-based statements reflects that the underlying reason for commissioning a statement dictates its format. One size does not fit all, and such is the case with ACVIM Consensus Statements as reflected by the variety of formats found in the 45 Consensus Statements published through the end of 2020. Most (n = 34, 76%) of these Consensus Statements are narrative reviews, although recently some statements have followed GRADE, Delphi or similar methodologies, likely reflecting increased recognition that ACVIM Consensus Statements should be developed using explicit and transparent criteria and methodologies. Of the 45 ACVIM Consensus Statements published between 2000 and 2020, only 13/45 (29%) describe the methodology used to develop the statement, 11 (24%) define particular questions to be addressed in the statement, 9 (20%) utilize descriptions of levels of evidence, and 4 (9%) address a limited number of questions (ie, narrowly define the topic) yet 20 (44%) provide specific recommendations. Clearly, guidelines in effect to date have not resulted in ACVIM Consensus Statements consistently conforming to contemporary standards for such expert statements. The ACVIM Consensus Statements make valuable contributions to the veterinary literature, providing practicing specialists and nonspecialists with recommendations developed by experts in the field and are consistently the most widely read of all articles published in the Journal of Veterinary Internal Medicine (based on downloads and citations). The ACVIM Consensus Statements are increasingly recognized as being an important source of expert advice and, as such, reflect well on the College. However, quality standards for such statements are increasing, and we believe that it is time that the College consider developing more uniform and rigorous practices and policies for creation of these statements. Doing so will ensure that readers of such expert statements are confident of the quality of the statement and that the statement reflects well on the ACVIM and the authors. The ACVIM supports the production of materials intended to assist clinicians and others in assessing the best available or optimal approach to providing veterinary care of animals or in understanding aspects of animal disease. These have been referred to as ACVIM Consensus Statements. One of the roles of the ACVIM is to identify appropriate topics and to ensure that these Consensus Statements are uniformly reliable and of high quality. To achieve this purpose, the ACVIM must ensure that topics are timely and relevant, panels are appropriately comprised of experts who are free of conflicts of interest, methodology is rigorous and transparent, and that there is a process for review of the draft statement. We proposed, and the Board of Regents accepted, that subsequent expert statements endorsed by the ACVIM be collectively referred to as AESs and that they be developed using specific methodologies. The roles of the Board of Regents and the Education and Research Committee may be modified from that proposed below to align with changes in the functions of the Board and Board officers. Narrative reviews, scoping reviews, and position papers are not considered suitable forms of AES. A narrative review provides a summary of current and relevant literature, but with few or limited comments on the quality of evidence and no formal recommendations for action. Importantly, they do not use PRISMA methodology.2, 15, 16 Scoping reviews do not seek to answer a particular question or questions, but are intended to identify certain characteristics or concepts in papers or studies, and examine the mapping, reporting or discussion of these characteristics or concepts.9 A position paper provides the view of an individual or group on a particular issue, is not developed with any defined methodology, and is in many cases an opinion piece. The appropriate format for an AES will vary depending on the topic, the available published evidence, and the intent of the statement. The AES can be developed using one of three approved methodologies. The methodology chosen for a particular AES will be decided as part of the process for selecting a topic, convening a panel, and developing specific questions. Consensus statements are always developed using the Delphi method and reflect the collective opinions of a group of content experts. The opinions of the experts will be based on their individual expertise, experience, and knowledge of the literature. Consensus is tested and demonstrated using prescribed methodology to identify areas of agreement and disagreement within the group of experts.14, 18 Consensus statements are applicable to situations where evidence is limited or lacking, but where there is the opportunity to reduce uncertainty and improve quality of care.6, 14 Consensus statements take advantage of the collective wisdom of a group of experienced clinicians and researchers, substituting expert opinion for objective fact. The opinion of the experts is based on their individual experience and knowledge of the relevant scientific literature. A consensus statement is applicable to situations where the evidence base is of insufficient quantity, quality, or is too varied for development of practice guidelines. An example of development of clinical consensus statements is the process used by otolaryngologists in human medicine.14 Consensus statements should not be based on a general statement of a topic (eg, “Asthma in cats”) but should be more narrowly focused. In this example, a more narrowly defined topic would be “Treatment of asthma in cats,” which addresses the specific statements: (1) inhaled corticosteroids are indicated; (2) betamethasone is the optimal inhaled corticosteroid; (3) oral corticosteroids are less effective than inhaled corticosteroids; and (4) beta-adrenergic bronchodilators are indicated. When considering the topic and its breadth, the available length of the final document should be considered. Statements should be concise and precise. Topics should be defined narrowly enough so as to be addressed within the limitations on length of the statement. Evidence-based practice guidelines (“guidelines”) guide provision of current best practice care to animals and are ideally based on a rigorous, methodical, evidenced-based review of the relevant literature. Guidelines have become increasingly important and useful to practicing clinicians given the increasing availability of novel or innovative treatments, interventions, or diagnostic methodologies and large quantity of scientific literature. Guidelines should have a consistent and transparent method of development, be of uniformly high quality, and be free of bias or conflict of interest by the developers of the guidelines. High quality guidelines recommend a course of action based on a comprehensive and systematic review, grading of the evidence, and explicit comparison of the benefits and harms of a given test or treatment, such as achieved by the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) process.4, 5, 7, 8, 14 The Institute of Medicine provides a detailed user guide for preparation of guidelines as does the Cochrane website and Cochrane handbook on preparation of systematic reviews and guidelines, which also includes access to software for preparing guidelines compliant with GRADE (https://gradepro.org/product/#about; Table 1).7, 10, 11 An important component of a Guideline is the Summary of Findings table. A Summary of Findings table presents the main findings of a review in a transparent and simple tabular format. In particular, the table provides key information concerning the quality of evidence, the magnitude of effect of the interventions examined, and the sum of available data on the main outcomes.7 Systematic reviews are important to veterinarians because they provide an objective assessment of existing data to assist with decisions about clinical practice, can provide rationale and justification for research, and are used as the basis for evidence-based practice guidelines. The usefulness of a systematic review depends on the methodology and the clarity of reporting. A systematic review is a review of a clearly formulated question that uses systematic and explicit methods to identify, select, and critically appraise relevant research, and to collect and analyze data from the studies that are included in the review. Statistical methods (meta-analysis) may or may not be used to analyze and summarize the results of the included studies. The methodology must follow that of PRISMA or Cochrane systematic reviews.15 PRISMA is an evidence-based minimum set of items for reporting in systematic reviews and meta-analyses. PRISMA focuses on the reporting of reviews that evaluate randomized trials, but can also be used as a basis for reporting systematic reviews of other types of research, particularly evaluations of interventions.19 The difference between evidence-based practice guidelines and systematic reviews relates more to the topic being reviewed and the scope of the review. Guidelines address an area of clinical practice and may have a large number of questions (>5) or statements to evaluate and collate in Summary of Findings tables. Guidelines provide explicit recommendations on clinical practice. Systematic reviews may address topics that are not directly related to clinical practice, for which there are a small number of questions (<5), or both. Systematic reviews might not provide explicit recommendations. The difference between the two approaches is not always clear and the methodologies have much in common. Historically, the topic was chosen by the At-Large BoR members after consulting with colleagues and solicitation of ideas from ACVIM Diplomates. Our opinion, after reviewing all of the ACVIM Consensus Statements published to date, is that the topics chosen have been timely and well-balanced with respect to topical areas that are important to the broad interests of ACVIM Diplomates. Ideally methods to receive proposals for topics from the ACVIM should continue to be developed. Oversight of the AES program will now be provided by the Education and Research Committee (ERC) of the ACVIM. We recommend that the ERC members, in consultation with the ACVIM BoR, develop a short list of proposed topics that then is posted on the ACVIM website, with the membership being notified and asked to respond within a specified period to rank and provide comments about the proposed topics, or make suggestions for additional topics. The process for developing an AES would be to agree on the general topic and then for the ERC to seek advice from the President of the relevant specialty and the Chair of the panel on the most suitable format (ie, consensus statement, guidelines, or systematic review). The ERC and the relevant specialty President, guided by the methodologist, will be responsible for final approval of the AES topic and format. The AES should be developed by a panel comprised of individuals who are widely recognized as having expertise on the topic. Ideally, most panel members will have published basic research, clinical studies, or both on the topic or in closely related areas. The process for identifying and selecting panel members should be carefully considered to ensure that selection is impartial, all potentially interested and qualified people have been identified and considered, potential conflicts of interest have been identified and effectively managed, the process for identifying panel members is accepted and actively supported by the ACVIM membership, and the final panel composition is approved by the ACVIM BoR, which may delegate this approval to the ERC. The process also likely will differ depending on the type of statement that is being developed (Table 2). Panels for all types of AES will have a Chair who will be assigned specific responsibilities documented in a formal role description. The panel Chair should be an ACVIM Diplomate unless there are strong reasons to select a non-ACVIM-Diplomate for this role. The Chair and, if needed, Assistant Chair, of each panel will be selected after the topic of the statement has been finalized, and will be identified by consultation of the ERC with the relevant specialty President (if the topic is relevant to more than one specialty, then the Presidents of each of the relevant specialties will participate in the appointment). The ERC may seek additional advice from content experts and may call for nominations for the role(s). The process for appointing panel members differs for each type of expert statement. Typically, recommendations for membership are developed by the panel Chair in consultation with the ERC and President of the relevant specialty, with the assistance of the methodologist. The final composition of each panel is approved by the ACVIM BoR, which may delegate this approval to the ERC. At least half of the expert panel should be ACVIM Diplomates. For the Delphi method, the panel Chair, Assistant Chair, President of the relevant specialty and ERC will select 2-3 panel members who will serve as core organizers and authors of the consensus statement. These panel members, with the support of a methodologist, then will identify the additional 11-25 participants who will provide expert opinions that are the basis for content for the consensus statement. The methodologist should have expertise in the Delphi method and ensure that the correct approach and format are followed. The methodologist also will participate in writing the final document and ensure that submission deadlines are met. After a call for nominations (including self-nomination), participants would be chosen from interested Diplomates who would need to provide evidence of their qualifications, including published research and clinical experience. Diplomates also could nominate qualified persons who are not members of the ACVIM (again, providing evidence of qualifications). The panel Chair, Assistant Chair, President of the relevant specialty and ERC will select 4-6 expert panelists who will work remotely to develop the guidelines, with the support of a methodologist. The methodologist should have expertise in the GRADE method and help ensure that the correct approach and format are followed. The methodologist also can participate in writing the final document and ensure that submission deadlines are met. After a call for nominations (including self-nomination), participants would be chosen from interested Diplomates who would need to provide evidence of their qualifications (ie, published research, clinical experience). Diplomates also could nominate qualified persons who are not members of the ACVIM (again, providing evidence of qualifications). When using PRISMA guidelines or the Cochrane methodology to conduct a systematic review, the ERC and President of the relevant specialty will select a content expert as panel Chair who then would recommend 2-3 other content experts familiar with the development of meta-analyses and systematic reviews to develop the statement. This approach also would benefit from the support of a methodologist familiar with meta-analyses and systematic reviews. Regardless of the method used to identify the panel Chair and members, the Chair should drive the process, encourage equal participation by all panel members, coordinate the roles of the panel members, ensure diversity of opinion, drive the writing process to meet submission deadlines, format and editorial standards, and manage any identified conflicts of interest that become apparent (including potentially having a member with a relevant conflict of interest recuse themselves from the panel). Where applicable, the definition of “consensus” must be based on criteria specified before the panel convenes to review evidence or prepare the content of their report. When a consensus statement is developed using the Delphi method, the planned number of rounds/iterations as well as criteria for stopping discussion should be specified before development of the consensus statement, and consensus will be defined as at least 75% agreement among authors.18 When the Guideline/GRADE approach is used, consensus or lack of consensus should be reported regarding rating of evidence quality and conclusions that can be drawn from that finding but is less impactful because recommendations are rated based on quality of evidence.7 When the systematic review methodology is used, reaching consensus is not generally necessary because recommendations are based on summarized, objective data. All AES will be made available to ACVIM Diplomates for review and comment before finalizing and publishing. The draft documents will be posted on the ACVIM website, available only to Diplomates, for online provision of comment and feedback. The document will be available for no less than 30 days and its availability will be announced to all ACVIM Diplomates by email. However, formal peer review of consensus statements or practice guidelines will not be conducted. At the discretion of the panel Chair and the JVIM Co-Editors-In-Chief, it may be appropriate and desirable to peer review for systematic reviews. of a of ACVIM Diplomates regarding Consensus Statements that the ACVIM membership is of the potential for conflict of interest to the and content of AES. is critically important that such conflicts be identified and managed, and the Chair of the panel and the with support from ACVIM should be with this of a potential does not management of that and care must be that does not the panel members and the panel Chair from management or for the A is a set of in which concerning a interest as a or the of could be by a interest as financial or of interest the and of these A an or individual potentially because of a between interests and or potential conflicts the to recommendations or the of statements a or has a interest as or that question their or decision-making can be of interest can in the of any financial When such a the is asked to recuse Importantly, or potential can the AES and the ACVIM unless clearly and from the of the concepts in are identifying the potential or and the To be managed, a must be This can be by the individual or by a considered by some to be critically important to there is limited evidence regarding the effect of Research that can have at is not the it is to These of the individual the from or for their role in developing an AES. could have the of or a the effect of the with a are to recuse themselves from (ie, decisions where such a conflict may be sufficient to recuse an individual regarding and decisions of a specific topic, or it may be more appropriate for an to be from in the AES. The to recuse depends the potentially individual identifying (ie, being and the potential and the individual themselves to a from the could be appropriate for a to the potential and to on to or the individual in AES panels would only members who are free of relevant to the topic of the statement. However, this will not always be or and must be in to identify and manage is and can be addressed by having the process widely with of the specific and management being of the statement, and management should be of information is as and panel The the ACVIM and the ACVIM President will review all information and determine any a potentially relevant The final recommendations on management of the are provided to the ACVIM BoR for and a relevant it will be as and This editorial was prepared by the authors and was not peer and are of the of the other authors a conflict of

73. Mid-infrared spectroscopy can identify changes in plasma profiles associated with dietary interventions: Untargeted omic screening

Animal - science proceedings · 2023-11-01

Potomac Horse Fever

Veterinary Clinics of North America Equine Practice · 2023-02-01 · 4 citations

A seasonal idiopathic hepatitis syndrome in horses presented to a Midwestern veterinary teaching hospital

Journal of the American Veterinary Medical Association · 2022 · 2 citations

• Medicine
• Internal medicine
• Gastroenterology

OBJECTIVE: To report history, clinical examination findings, clinicopathologic findings, diagnostic test results, treatment, and outcome in horses with a novel idiopathic hepatitis syndrome. ANIMALS: 13 client-owned horses. PROCEDURES: Medical records of horses that were presented with fever and increased blood liver enzyme activity over a 16-month period were reviewed (December 1, 2020, to April 1, 2022). Collected data included signalment, history, clinical and clinicopathologic findings, diagnostic test results, treatment, clinical progression, and short-term outcome. RESULTS: Affected horses were presented between December and April of each of the 2 seasons investigated. The majority of horses developed cyclic fevers over the course of 3 weeks, during which time histologic evidence of hepatitis was observed. Histologic lesions included hepatic necrosis, neutrophilic to lymphohistiocytic inflammation, biliary epithelial injury, and portal fibrosis. Systemic inflammation was evidenced by increased serum amyloid A concentration and leukon changes. No horse developed signs of hepatic insufficiency, and all horses clinically recovered. Return of serum activity of GGT to within the reference range occurred within 16 weeks in most horses. Histologic lesions remained evident up to 27 weeks after initial presentation in 1 horse. CLINICAL RELEVANCE: Although an etiologic agent has not been identified, an apparently seasonal equine hepatitis syndrome was characterized by fever, systemic inflammation, increased liver enzyme activity, and histologic evidence of hepatitis. An infectious cause is suspected on the basis of histology and outcome.