Equine Disease Research Articles

Equine glandular gastric disease in adult horses

Equine glandular gastric disease is a separate entity from equine squamous gastric disease and is, until proven otherwise, a syndrome with different underlying causes. Gastroscopy is the mainstay of diagnosis, with an understanding that what is seen at the pylorus may not reflect the whole picture of squamous or glandular disease. The pathophysiology is still not understood, which limits understanding of how to effectively treat the condition. Clinical signs relate to changes in broad themes including changes in temperament (including cutaneous hypersensitivity), rideability and appetite, which may result in weight loss. Risk factors for glandular gastric disease are different to squamous gastric disease and include exercise for more than 4 days per week, multiple caretakers, being less experienced at the discipline that they compete in and less adaptable to stress. Limitations in progress of understanding of this condition include a better understanding of the pathophysiology and what findings mean regarding clinical signs and response to therapy, consistent definitions of healing and improvement, evaluating adjunctive products as adjunctives and not as medicines and large multi-centre studies using appropriate statistics.

Survey of state animal health officials reveals lack of personnel and resources to manage equine infectious disease outbreaks.

The purpose of the study was to assess the challenges faced by state animal health officials (SAHOs) when managing equine disease outbreaks. A survey was conducted to assess SAHOs' collaboration with horse owners and practicing veterinarians to provide biosecurity and infection disease control. It was sent to 180 email addresses listed in the Equine Disease Communication Center website database. The responses in each category for each question were tabulated and reported as a percentage. There were 72 survey responses from 45 states. The number of states responding suggested that the results represent SAHOs' current opinions. Fifty percent of responders identified the lack of resources and training for equine health management and equine reportable disease prevention and control. There is a lack of owner compliance in managing disease outbreaks, and boarding stables, horse shows, and racing facilities require the most resources for outbreak management. The survey indicated on-site communication as the most effective for managing an outbreak, and the Equine Disease Communication Center is to be a valued resource for alerts and disease information. At the state level, there is a lack of needed personnel and resources to effectively manage an equine infectious disease outbreak. Furthermore, failure of veterinary and owner compliance in reporting and managing equine infectious diseases allows disease spread. Lack of sufficient resources for management of reportable diseases will potentially result in disease spread with a negative impact on horse health and the equine industry.

RNA structures within Venezuelan equine encephalitis virus E1 alter macrophage replication fitness and contribute to viral emergence.

Venezuelan equine encephalitis virus (VEEV) is a mosquito-borne +ssRNA virus belonging to the Togaviridae. VEEV is found throughout Central and South America and is responsible for periodic epidemic/epizootic outbreaks of febrile and encephalitic disease in equines and humans. Endemic/enzootic VEEV is transmitted between Culex mosquitoes and sylvatic rodents, whereas epidemic/epizootic VEEV is transmitted between mosquitoes and equids, which serve as amplification hosts during outbreaks. Epizootic VEEV emergence has been shown to arise from mutation of enzootic VEEV strains. Specifically, epizootic VEEV has been shown to acquire amino acid mutations in the E2 viral glycoprotein that facilitate viral entry and equine amplification. However, the abundance of synonymous mutations which accumulate across the epizootic VEEV genome suggests that other viral determinants such as RNA secondary structure may also play a role in VEEV emergence. In this study we identify novel RNA structures in the E1 gene which specifically alter replication fitness of epizootic VEEV in macrophages but not other cell types. We show that SNPs are conserved within epizootic lineages and that RNA structures are conserved across different lineages. We also identified several novel RNA-binding proteins that are necessary for altered macrophage replication. These results suggest that emergence of VEEV in nature requires multiple mutations across the viral genome, some of which alter cell-type specific replication fitness in an RNA structure-dependent manner.

A multi-task learning model for clinically interpretable sesamoiditis grading

Sesamoiditis is a common equine disease with varying severity, leading to increased injury risks and performance degradation in horses. Accurate grading of sesamoiditis is crucial for effective treatment. Although deep learning-based approaches for grading sesamoiditis show promise, they remain underexplored and often lack clinical interpretability. To address this issue, we propose a novel, clinically interpretable multi-task learning model that integrates clinical knowledge with machine learning. The proposed model employs a dual-branch decoder to simultaneously perform sesamoiditis grading and vascular channel segmentation. Feature fusion is utilized to transfer knowledge between these tasks, enabling the identification of subtle radiographic variations. Additionally, our model generates a diagnostic report that, along with the vascular channel mask, serves as an explanation of the model’s grading decisions, thereby increasing the transparency of the decision-making process. We validate our model on two datasets, demonstrating its superior performance compared to state-of-the-art models in terms of accuracy and generalization. This study provides a foundational framework for the interpretable grading of similar diseases.

Pharmaceutical treatment of equine glandular gastric disease: A contextualised review of recent developments

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.

Onchocerca cervicalis: an underestimated cause of equine skin disease?

Onchocerca cervicalis: an underestimated cause of equine skin disease?

Equine squamous gastric disease: an update on treatment and management

Equine squamous gastric disease: an update on treatment and management

Extensive survey of equine infectious diseases in Argentina: equine infectious anaemia, glanders, surra, and dourine

Extensive survey of equine infectious diseases in Argentina: equine infectious anaemia, glanders, surra, and dourine

Streptococcus equi subspecies equi from strangles suspected equines: molecular detection, antibiogram profiles and risk factors

Strangles, caused by Streptococcus equi subspecies equi, is a highly infectious disease of equines causing major health issues and financial losses. The aim of the study was to detect the presence of the SeM gene in Streptococcus equi isolated from equine suspected of having strangles. A cross-sectional study design was conducted from July to December 2022 in five districts of the central Gondar zone, Ethiopia. One-hundred sixty swab samples were taken from animals that had been clinically suspected. The SeM gene was detected using polymerase chain reaction, and the antimicrobial susceptibility test was performed using the Kirby-Bauer disc diffusion method. The binary logistic regression model was employed to test for statistical significance. In 31.87% (51/160) of the samples, Streptococcus equi species were isolated, and 31.37% (16/51) of these species carried the SeM gene. There was a significant amount of tetracycline (81.5%), erythromycin (81.5%), and vancomycin (75.5%) resistance among the 16 isolates. Strangles were more likely to be present in animals who shared feed containers (AOR = 7.59; 95% CI = 1.44–39.93), drank from the same water troughs (AOR = 7.74; 95% CI = 1.44–41.01), and spent the night together (AOR = 5.97; 95% CI 1.41–25.37). The findings of this study showed that the research areas harboured Streptococcus equi subspecies equi. Sharing feed containers and water troughs were potential sources of strangles infection; thus, these containers need to be cleaned regularly.

Hyalomma marginatum - an emerging tickborne disease vector for the UK?

The tick Hyalomma marginatum is expanding its geographical range, reinforcing the need for surveillance and control to prevent the emergence of tickborne equine disease. Daniel Armstrong, policy adviser for exotic animal diseases at Defra, explains more.

Equine disease surveillance: quarterly update.

Equine disease surveillance: quarterly update.

Metastatic renal carcinoma in a horse presented for lameness examination and suspected pneumonia

AbstractEquine renal cell carcinoma (RCC) is a rare and poorly understood condition, making the diagnosis challenging. We present a case of a 16‐year‐old Warmblood gelding referred for lameness and suspected pneumonia. The horse exhibited diverse non‐specific symptoms, including pyrexia, coughing, weight loss and lameness. Diagnostic imaging revealed an osseous neoplastic lesion and lung metastasis. Postmortem confirmed metastatic renal carcinoma. This case underscores the difficulty of RCC diagnosis due to non‐specific clinical signs, necessitating a comprehensive approach involving clinical, imaging and histopathological findings. RCC offers limited treatment options as it is typically diagnosed at advanced stages, leading to a poor prognosis and euthanasia. Increased awareness and research are crucial for early detection and better understanding of this rare equine disease.

Review of equine glandular gastric disease

SummaryEquine glandular gastric disease (EGGD) is a common disorder of horses that presents challenges in both diagnosis and treatment for equine veterinarians. Because clinical signs are non‐specific, diagnosis requires endoscopy. Lesion grading may be inconsistent due to challenges in interpreting endoscopic findings, which complicates diagnosis and monitoring. Successful management is difficult due to the multifactorial pathogenesis of disease. This review will provide an overview of the epidemiology, pathogenesis, diagnosis and approach to the management of EGGD.

Changes in saliva analytes in equine gastric ulcer syndrome (EGUS) after treatment: a pilot study

Equine gastric ulcer syndrome (EGUS) is a prevalent condition in horses, affecting up to 93% of racehorses. Comprising the equine squamous gastric disease (ESGD) and the equine glandular gastric disease (EGGD), EGUS poses significant health challenges. Saliva, a non-invasive and easily obtainable sample, is increasingly recognized for its potential as a source of biomarkers in horses. This study investigates changes in saliva analytes using automated assays before and after EGUS treatment, aiming to identify biomarkers indicative of treatment success or failure. A total of 28 horses diagnosed with EGUS were treatment with omeprazole for six weeks and further divided into successful (n = 15) or unsuccessful (n = 13) treatment group. Saliva samples were collected before and after treatment, and analytes related to enzymes, metabolites, proteins, redox biomarkers, and minerals were measured using an automated chemistry analyzer. Results revealed that horses with successful treatment, indicated by reduced EGGD and ESGD scores, showed significant increases in bicarbonate and urea, and decreases in adenosine deaminase (ADA), and creatine kinase (CK). Conversely, horses with non-successful treatment showed no significant changes in salivary analytes. These analytes have the advantages of an easy and fast measurement and the possibility of being applied in routine. Further studies with larger populations should be performed to establish the possible practical application of these analytes as biomarkers of treatment.

Equine gamma herpesvirus presence and viral load are not associated with equine glandular gastric disease

Equine gamma herpesvirus presence and viral load are not associated with equine glandular gastric disease

Equine glandular gastric disease—effectiveness of misoprostol therapy based on 460 gastroscopies of 148 horses

Equine glandular gastric disease—effectiveness of misoprostol therapy based on 460 gastroscopies of 148 horses

Comparison of oral esomeprazole and oral omeprazole in the treatment of equine squamous gastric disease

Comparison of oral esomeprazole and oral omeprazole in the treatment of equine squamous gastric disease

Biosecurity perceptions among Ontario horse owners during the COVID-19 pandemic.

Disease outbreaks present a significant challenge to horse health and welfare and the economic stability of horse industries internationally. This is a particular concern in Ontario, Canada, where there have been frequent outbreaks of respiratory infectious diseases among horses. Despite these risks, there has been limited research on whether Ontario horse owners engage in biosecurity measures sufficient to mitigate risk of equine diseases, and whether current events such as the COVID-19 pandemic influence attitudes towards equine biosecurity practices. To explore Ontario horse owners' perceptions, attitudes and experiences relating to on-farm biosecurity during the COVID-19 pandemic. Qualitative study using virtual semi-structured interviews. Participants (horse owners, frequent horse riders and part boarders) were recruited using social media snowball sampling where advertisements were shared by equine and veterinary organisations. Interviews were conducted virtually between June and September 2022 and were analysed using reflexive thematic analysis. Three key themes relating to biosecurity perceptions among the 14 participants were identified. Participants relied on minimal preventative measures (such as vaccines) where perceived risk of disease was low, but implemented additional measures including quarantine and handwashing when perceived risk of disease was high. Participants' choice of biosecurity practices often mirrored those recommended by the barn manager. Moreover, participants felt that responsibility for biosecurity was not shared equally across horse owners, with more emphasis placed on those engaging in high-risk situations for disease spread. Despite experiencing biosecurity during the COVID-19 pandemic, horse owners were not consistently applying these practices to their horse care routines. The perspectives reported here are from a small sample of horse owners and may not be generalisable to all populations. Our findings indicate that horse owners need improved access to and engagement with educational initiatives that emphasise the importance and purpose of all biosecurity measures.

Shotgun proteomics of detergent-solubilized proteins from Trypanosoma evansi

Trypanosoma evansi, the causative agent of surra, is the most prevalent pathogenic salivarian trypanosome and affects the majority of domesticated and wild animals in endemic regions. This work aimed to analyze detergent-solubilized T. evansi proteins and identify potential diagnostic biomarkers for surra. Triton X-114-extracted membrane-enriched proteins (MEP) of T. evansi bloodstream forms were analyzed using a gel-free technique (LC-ESI-MS/MS). 247 proteins were identified following the MS analysis of three biological and technical replicates. Two of these proteins were predicted to have a GPI-anchor, 100 (40%) were predicted to have transmembrane domains, and 166 (67%) were predicted to be membrane-bound based on at least one of six features: location (WolfPSORT, DeepLoc-2.0, Protcomp-9.0), transmembrane, GPI, and gene ontology. It was predicted that 76 (30%) of proteins had membrane evidence. Typical membrane proteins for each organelle were identified, among them ISG families (64, 65, and 75 kDa), flagellar calcium-binding protein, 24 kDa calflagin, syntaxins and oligosaccharyltransferase some of which had previously been studied in other trypanosomatids. T. evansi lacks singletons and exclusive orthologous groups, whereas three distinct epitopes have been identified. Data are available via ProteomeXchange with identifier PXD040594. SignificanceTrypanosoma evansi is a highly prevalent parasite that induces a pathological condition known as “surra” in various species of ungulates across five continents. The infection gives rise to symptoms that are not pathognomonic, thereby posing challenges in its diagnosis and leading to substantial economic losses in the livestock industry. A significant challenge arises from the absence of a diagnostic test capable of distinguishing between Trypanosoma equiperdum and T. evansi, both of which are implicated in equine diseases. Therefore, there is a pressing need to conduct research on the biochemistry of the parasite in order to identify proteins that could potentially serve as targets for differential diagnosis or therapeutic interventions.

Coloration in Equine: Overview of Candidate Genes Associated with Coat Color Phenotypes.

Variation in coat color among equids has attracted significant interest in genetics and breeding research. The range of colors is primarily determined by the type, concentration, and distribution of melanin pigments, with the balance between eumelanin and pheomelanin influenced by numerous genetic factors. Advances in genomic and sequencing technologies have enabled the identification of several candidate genes that influence coat color, thereby clarifying the genetic basis of these diverse phenotypes. In this review, we concisely categorize coat coloration in horses and donkeys, focusing on the biosynthesis and types of melanin involved in pigmentation. Moreover, we highlight the regulatory roles of some key candidate genes, such as MC1R, TYR, MITF, ASIP, and KIT, in coat color variation. Moreover, the review explores how coat color relates to selective breeding and specific equine diseases, offering valuable insights for developing breeding strategies that enhance both the esthetic and health aspects of equine species.