Disease diagnosis in horses involves the identification and characterization of illnesses through various diagnostic methods and tools. This process is essential for effective veterinary care and management of equine health. Techniques used in diagnosing diseases in horses include clinical examinations, laboratory tests, imaging modalities such as ultrasonography and radiography, and molecular diagnostics. Blood tests are frequently utilized to assess parameters such as complete blood count and biochemical profiles, which can indicate underlying health issues. Additionally, advancements in genetic testing and biomarker identification have enhanced the ability to detect specific diseases early. This page aggregates peer-reviewed research studies and scholarly articles that explore diagnostic methodologies, their applications, and their impact on equine health management.
Aldworth-Yang S, Coleman SJ, O'Reilly K, Catalano DN.Artificial intelligence (AI) platforms are becoming increasingly popular as resources for equine information. However, these platforms generate responses from a wide range of sources and do not always distinguish between fact and opinion. Objective: The objective of this study was to assess the accuracy and quality of AI-generated answers to equine-related questions. Researchers hypothesized that AI platforms could answer basic equine questions effectively but would perform poorly on complex topics or questions. Methods: Forty questions were written covering general horse care, facilities mana...
Romanucci M, Baghini S, Canonici F, Canonici P, Di Luzio Paparatti F, Marruchella G.Neck masses may represent a diagnostic challenge for equine veterinarians, since they may involve different structures with a similar clinical appearance. Whereas neck masses in foals mostly result from non-neoplastic conditions, including various congenital abnormalities, neoplastic cervical masses have been rarely documented. This report describes the unusual case of a rapidly growing neck cancer in a four-month-old colt, resulting in a fatal outcome. Gross and immunohistological findings were most consistent with a poorly differentiated thymic carcinoma with sarcomatoid features and multifo...
Pereira LMA, Schade J, Pereira LMA, Tocheto R, Cristo TG, Casagrande RA, Souza AF, Fonteque JH.This study aimed to determine the occurrence of swellings (lampas) in the rostral portion of the hard palate in young, adult, and elderly horses and to characterize them histologically. One hundred and twenty horses of different ages were evaluated by oral inspection. Horses were classified with lampas when the mucosa of the hard palate extended beyond the occlusal surface of the upper incisors and samples of palatal mucosa were collected. Ten other horses without rostral hard palate alterations, euthanized for unrelated causes, were included as the control group. Histological analysis include...
Petersen JL, Finno CJ.A prior genome-wide association (GWA; N = 200) including Thoroughbreds and stock horses implicated chromosome 6 (NC_009149.3) in owner-reported equine anhidrosis. A missense variant in KCNE4 (NC_009149.3:g.11813731A>G) was proposed as a risk allele, although its association with anhidrosis was not reported. Variant annotation and protein modelling in the original study suggested the G allele conferred risk. We reported no association of the G allele with anhidrosis in 50 horses phenotyped by an intradermal terbutaline sweat test (ITST); all horses produced sweat regardless of genotype. ...
Kanani Y, Oryan A, Derakhshandeh A.Burkholderia mallei is the causative agent of glanders, a serious zoonotic disease of major concern for both animal and human health. This highly contagious and potentially fatal bacterium is always classified as a biothreat agent. In this review, we covered a comprehensive overview of glanders, including the biology of the pathogen, epidemiology, pathogenesis, diagnosis, control strategies and ongoing eradication programs in Eurasia. We also summarized human case reports, differential diagnosis, treatment and organism's antimicrobial properties. The section on vaccine development is among the...
Hallsten M, Fogle C, Shippy S, Hobbs KJ, Blikslager AT, Elane GL.To describe the sensitivity, specificity, predictive values, and accuracy of abdominal palpation per rectum in horses treated surgically for colic. Unassigned: Medical records were gathered over 5 years (2019 to 2024). Findings of abdominal palpation per rectum were collected and compared to surgical diagnosis, and cases were categorized as true or false positive and negative. Signalment, physical examination parameters, hematologic values, and years of examiner experience were recorded. Unassigned: Records of 453 horses were included. Overall sensitivity and positive predictive value were 86%...
Zeldenrust EG, Carlton K, Jenkins EJ, Moré G, Nielsen MK, Pearl DL, Schott CR, Terier SM, Barta JR.Klossiella equi Baumann, 1946 (Apicomplexa: Coccidia) is a globally distributed adeleorinid parasite that infects the kidneys of equid hosts. Considered an uncommon parasite, when K. equi is detected, it is typically an incidental finding during histologic examination of the kidneys as part of routine necropsy. In the present study, kidney was collected opportunistically from 3 different equine populations: 1) routine necropsies at the Ontario Veterinary College (OVC; n = 48); 2) natural mortalities from the Sable Island wild horse herd (n = 25); and 3) routine necropsies of animals fr...
Helber L, Wagner B, Leeth CM, LeRoith T, Cecere TE, Lahmers KK, Andrews FM, Hay AN, Werre SR, Johnson AL, Clark CK, Pusterla N, Reed SM, Lindsay DS....Currently, little is known about the exact role of immunopathology in equine protozoal myeloencephalitis (EPM), including the ability to persist after anti-protozoal treatment. The main objectives of this study were to determine whether is present in the CNS in horses with EPM, including previously treated cases, and to evaluate the associated histopathology and immune response. For this study, control ( = 10) and horses with EPM ( = 9) were confirmed based on our inclusion criteria. Based on our preliminary data, we classified horses with EPM and clinical signs for >6 months as...
Vanderbiest L, Rousseau L, Renaville B, Aleman M, Finno C, Milan A, Vinardell T.Occipitoatlantoaxial malformations (OAAM) are developmental disorders occurring at the occiput, atlas and axis. OAAM type 1 is a familial disorder affecting Arabian horses. Currently, a single genetic mutation in the HOXD3 gene region can be tested to confirm the diagnosis. This case describes a 3-year-old Arabian gelding affected with OAAM. Clinical examination revealed a proximal cervical deformation on the right side and severe stiffness of the neck in the sagittal plane without associated pain. Neurological examination demonstrated a generalized proprioceptive ataxia. Radiographs revealed ...
Federico F, Amie W, Alzbeta C, Anders J, David LP, Mandy PJ.Cerebrospinal fluid (CSF) is a valuable source of biomarkers for neurological diseases, but detection of low-abundance proteins is often masked by highly abundant proteins. Enrichment strategies can enhance proteomic coverage and improve biomarker discovery, yet comparative evaluations of such methods in equine CSF are limited. Objective: This study compared the ProteoMiner Small-Capacity Enrichment Kit and the PreOmics Enrich-iST Kit for their ability to deplete high-abundance proteins and enhance detection of low-abundance proteins relevant to neuropathology. Methods: Equine CSF samples were...
Erdoğan MS.Radiographic measurement parameters play a key role in diagnosing acute and subacute laminitis in horses, with diagnostic thresholds typically derived from empirical receiver operating characteristic (ROC) analysis. However, these methods often produce unstable results, particularly in small or noisy datasets. This study applies nonuniform rational B-spline (NURBS)-based ROC smoothing to radiographic data from laminitic and healthy horses to evaluate its effectiveness in refining diagnostic thresholds. Thresholds are determined using Youden's index based on NURBS-smoothed ROC curves and compar...
Hayashi M, Yonetamari J, Muto Y, Kinoshita Y, Uchida E, Niwa H, Fujiwara N, Nakaya M, Yamagishi Y, Tanaka K.In this study, five strains of anaerobic, Gram-negative, rod-shaped bacteria were characterized phenotypically, biochemically and genotypically. These strains were clinically isolated from horse specimens in Japan. Phylogenetic trees constructed based on 16S rRNA gene sequence comparisons showed distinct clustering of the five strains with the type strains of closely related species. The genomic DNA G+C content was 46.7 mol%. The major cellular fatty acids identified were C, 3-OH-C and 3-OH-iso-C. Whole-genome comparisons based on average nucleotide identity using blast (ANIb) and digital DNA...
Bostick HN, Keys DA, Bowden AC, McMullen RJ.To compare equine optic nerve head (ONH) measurements using spectral domain optical coherence tomography (SD-OCT) to detect clinically relevant ONH cupping. Methods: Forty-five eyes from 34 horses were categorized as CONTROL or CUPPED based on indirect ophthalmoscopy and were measured using SD-OCT: Bruch's membrane opening (BMO), optic cup width (OC), anterior laminar depth (ALD), prelaminar thickness (PLT), and cup-to-disk ratio (OC: BMO) at superior (sup.), central (ctr.), and inferior (inf.) ONH locations. Results: The OC:BMO was 0.61 ± 0.09 (sup.), 0.64 ± 0.09 (ctr.), and 0.55 ...
Manso-Díaz G.Diagnostic imaging is essential for evaluating and managing neurologic disease in horses. Following clinical lesion, neurolocalization imaging modalities are often necessary to further characterize the disease process. However, which technology to use depends on various factors, including the patient's size, clinical signs, and the anatomic region. Current advances in imaging technology, in general, and the adaptation of different modalities for equine patients, in particular, have substantially improved our ability to evaluate the equine central nervous system. This article will summarize the...
Smith MA, Ripley N, Gravatte H, Nielsen MK.With rising anthelmintic resistance in adult cyathostomins, the most pervasive equine parasites, the need to assess larvicidal efficacy has increased, yet available methods remain limited. Encysted larvae are quantified using mucosal digestion, wherein a 5% subsample of intestinal mucosa is processed, and a 2% aliquot is counted for early third stage (EL3) and late third stage/mucosal fourth stage (LL3/L4) larvae. This method is imprecise and post-treatment larval differences are often not observed. The following study aimed to assess standard and modified protocol precision and sensitivity. I...
Naveed A, Eertink LG, Soni S, Kennedy MA, Adam E, Wang D, Li F.Equine rotavirus A (ERVA) poses a significant threat to foal health, necessitating reliable serological tools for assessing protective immune responses. This study focused on the development of an enzyme-linked immunosorbent assay (ELISA) for the measurement of antibodies against the VP8∗ receptor binding core domain of ERVA. Following the expression and purification of VP8∗ receptor binding domain from the bacterial expression system, the ELISA for detecting anti-ERVA VP8∗ antibodies with VP8∗ as a coating antigen was developed and its performance was validated by the comparative anal...
Alvarado Soto GJ, Maldonado M, Armentrout A, Woolard K, Aleman M, Giaretta P, Willis AT.Achalasia is the most common motility disorder of the esophagus in humans and has been diagnosed in cats and dogs. We describe a 4-month-old Quarter Horse colt with failure to thrive, recurrent colic episodes, and aspiration pneumonia, in which fluoroscopic evaluation identified a caudal esophageal motility disorder consistent with achalasia. Necropsy examination confirmed achalasia.
Pimenta J, Martins B, Mexedo A, Campilho R, Silva F, Cotovio M.Equine Gastric Ulcer Syndrome is a highly prevalent condition, yet its clinical diagnosis remains challenging due to the nonspecific nature of many associated signs. The relationship between the anatomical location of gastric ulcers and clinical presentation is still poorly defined. This retrospective study aimed to evaluate the association between gastric ulcer location and the clinical signs observed in horses. Medical records of 52 horses diagnosed with gastric ulcers by gastroscopy were retrospectively reviewed. Clinical signs were classified as physical, behavioral, or mixed, and ulcer lo...
van Erck-Westergren E, O'Connor S, Stewart BD, Dubois G, Morton J, Hinchcliff KW, Ter Woort F.The frequency, characteristics, and relationship with performance of arrhythmias occurring during high-intensity exercise in Thoroughbred racehorses remain poorly understood. Objective: Describe the frequency, characteristics, and association with subsequent race performance of arrhythmias occurring during intense exercise. Methods: Seventy-one racehorses competing in races sanctioned by the Hong Kong Jockey Club. Methods: Risk-based case-control study. Single-lead ECGs were recorded during high-intensity trials using wearable devices. Ectopic depolarizations identified during warm-up, maximal...
Shams N, Jaydari A, Khademi P, Eydi J, Sgroi G.Due to the abundance of ticks on open grassy surfaces, racetracks may represent ideal scenarios for tick-borne pathogens. Therefore, in 2024/2025 Turkmen horses (Akhal-Teke breed) and ticks collected by dragging in paddocks of Iran were screened for Anaplasmataceae using Sanger sequencing on 16S rRNA, TRP36 and dsb genes. Amongst 200 horses, 11 (5.5%) tested positive without signs/symptoms, being 8 (4%) for Ehrlichia canis and 3 (1.5%) for Anaplasma ovis; no difference in prevalence was found by gender and age (p>0.05). All ticks were identified as Hyalomma asiaticum and Haemaphysalis sulca...
Sévin C, Duquesne F, Copin S, Raguenet V, Guy M, Wilhelm A, Gassilloud B, Moreau P, Petry S.A retrospective review of equine necropsies performed at the Normandy Laboratory for Animal Health, French Agency for food, environmental and occupational health and safety (1996-2022) unexpectedly reported Vibrio alginolyticus, Vibrio parahaemolyticus and Vibrio vulnificus in equine samples using API 20NE, prompting a re-evaluation of bacterial identification. Of 27 strains, 25 were cultivable, and re-examined using API 20NE, API 20E, MALDI-TOF, 16S rRNA gene sequencing and Vibrio-specific PCR assays. API 20NE confirmed the original (erroneous) identifications; all Vibrio-specific PCR assays ...
Blangy-Letheule A, Montnach J, Perrier J, Lemonnier LC, Denis M, Rozec B, Lauzier B, Leroux AA.Colic is a leading cause of mortality in horses, particularly when associated with systemic inflammation and organ dysfunction. In human medicine, these complications are associated with sepsis, defined as organ dysfunction caused by a dysregulated, life-threatening host response to infection. However, no consensus sepsis score exists for adult horses. This retrospective study aimed to develop a diagnostic sepsis score for adult horses. Medical records from 295 horses admitted for colic to the Oniris equine emergency department (Nantes, France) between July 2011 and November 2021 were analyzed...
Onyiche TE, Peng TL.Potomac Horse Fever (PHF), also known as equine neorickettsiosis (EN) or equine monocytic ehrlichiosis is an acute, potentially fatal infectious disease in horses caused by the monocytotropic rickettsia bacterium Neorickettsia risticii. This obligate intracellular bacterium is maintained throughout the life cycle of digenetic trematodes which utilize multiple intermediate and definitive hosts. Research on N. risticii is scattered across multiple continents, with most studies originating from North and South America. Therefore, a systematic review is needed to consolidate global evidence, clari...
Basso RM, Cerri FM, Braga PRC, Silva ROS, de Araújo Júnior JP, Oliveira-Filho JP, Pantoja JCF, Ribeiro MG, Arroyo LG, Borges AS.Diarrhea is a significant cause of morbidity and mortality in foals. Our hypothesis is that foals with diarrhea have a greater prevalence of ≥2 organisms causing coinfections. We investigated the major microorganisms associated with diarrhea in 200 foals up to 1-y-old (100 diarrheic and 100 non-diarrheic). Fecal samples were analyzed by real-time PCR (rtPCR) for the detection of and toxin genes and , (genotyping for toxin-encoding genes), spp., , , , , , and spp. Rotavirus A and coronavirus were detected using reverse-transcription rtPCR. Fecal bacterial culture was also performed for ...
Mackowski M, Kajdasz A, Laskowska K, Cieslak J.Although serological and genetic studies of equine blood group systems have been conducted for many years, the molecular basis of erythrocyte antigens' variability has remained largely unexplored. In this study, we aimed to elucidate the genetic basis of serological variation within equine blood group K. Using mRNA extracted from peripheral blood samples (n = 100) collected from horses with known serological blood types (Ka or K-), we performed a transcriptome-wide association study (TWAS), which revealed a significantly associated region on equine chromosome 2 (ECA2). A detailed analysis ...
Jasiński T, Borowska M, Juszczuk-Kubiak E, Turek B, Kaczorowski M, Bąk M, Żuk J, Domino M.Horses presenting with temporomandibular joint (TMJ) dysfunctions are often clinically evaluated for TMJ osteoarthritis (OA). Due to the unique characteristic of TMJ-related pain, the clinical diagnosis of equine TMJ OA is challenging; however, it may be supported by computer-aided tools incorporating biomarker data. This study aims to evaluate a machine learning-based approach to address a binary classification distinguishing healthy TMJs from TMJ OA. Among 50 equine cadaver heads, 82 TMJs were included and annotated as healthy or OA based on histological and computed tomography (CT) findings...
Kareskoski AM.Behavioral issues, such as persistent or strong estrus, non-specific pain, and performance challenges in mares are frequently attributed to the estrous cycle. Objective: The objectives of this study were to analyze retrospective data on mares presented for estrus-related behavioral complaints, and to propose a structured diagnostic framework for categorizing cases during work-up at different levels of care. Methods: A retrospective study was conducted using patient records of a total of 14993 mares. Results: In this data set, behavioral problems, pain, or poor performance were not repeatably v...
Cornelisse K, Ionescu AM.Keesjan Cornelisse and Andra-Maria Ionescu discuss the clinical presentation, investigation and diagnostic approach to a case of orthoflavivirus infection in a horse in south-west England.
Sapper CB, Koch C, Schweizer D, Cunha Silva L, Pauwels FE, Klopfenstein MD, de Preux M, Van der Vekens E.Lesions of the tendons and manica flexoria (MF) within the digital flexor tendon sheath (DFTS) are a common cause for lameness in horses. This prospective study compared and quantified the agreement and disagreement of positive contrast computed tomographic tenography (CTT), positive contrast radiographic tenography (RXT), ultrasonography (US) and tenoscopy for diagnosing naturally occurring lesions within the DFTS, without application of a gold standard. Lesions affecting the deep (DDFT) and/or superficial digital flexor tendon (SDFT), and/or the MF and/or constriction of the palmar/plantar a...
Elsawy BSM, Alzan HF., a recently discovered tick-borne hemoparasite infecting equids globally, has significant implications for equine health. Although it is closely related to (sharing 23% genomic divergence), it establishes an asymptomatic carrier state in persistently infected horses, creating a silent transmission reservoir. Its discovery and unique genetics justify its classification as a new taxon. A critical diagnostic challenge is that the lack of the gene in prevents its detection by the standard cELISA, emphasizing the need for species-specific tools. Although species-specific PCR assays, including ...
Coles GC, Bauer C, Borgsteede FH, Geerts S, Klei TR, Taylor MA, Waller PJ.Methods have been described to assist in the detection of anthelmintic resistance in strongylid nematodes of ruminants, horses and pigs. Two tests are recommended, an in vivo test, the faecal egg count reduction test for use in infected animals, and an in vitro test, the egg hatch test for detection of benzimidazole resistance in nematodes that hatch shortly after embryonation. Anaerobic storage for submission of faecal samples from the field for use in the in vitro test is of value and the procedure is described. The tests should enable comparable data to be obtained in surveys in all parts o...
Connor RJ, Kawaoka Y, Webster RG, Paulson JC.The receptor specificity of 56 H2 and H3 influenza virus isolates from various animal species has been determined to test the relevance of receptor specificity to the ecology of influenza virus. The results show that the receptor specificity of both H2 and H3 isolates evaluated for sialic acid linkage specificity and inhibition of hemagglutination by horse serum correlates with the species of origin, as postulated earlier for H3 strains based on a limited survey of five human, three avian, and one equine strain. Elucidation of the amino acid sequence of several human H2 receptor variants and a...
Kaplan RM.Reports of drug resistance have been made in every livestock host and to every anthelmintic class. In some regions of world, the extremely high prevalence of multi-drug resistance (MDR) in nematodes of sheep and goats threatens the viability of small-ruminant industries. Resistance in nematodes of horses and cattle has not yet reached the levels seen in small ruminants, but evidence suggests that the problems of resistance, including MDR worms, are also increasing in these hosts. There is an urgent need to develop both novel non-chemical approaches for parasite control and molecular assays cap...
Kaplan RM, Vidyashankar AN.Over the past 10-15 years, we have witnessed a rapid increase in both the prevalence and magnitude of anthelmintic resistance, and this increase appears to be a worldwide phenomenon. Reports of anthelmintic resistance to multiple drugs in individual parasite species, and in multiple parasite species across virtually all livestock hosts, are increasingly common. In addition, since the introduction of ivermectin in 1981, no novel anthelmintic classes were developed and introduced for use in livestock until recently with the launch of monepantel in New Zealand. Thus, livestock producers are often...
Murray K, Selleck P, Hooper P, Hyatt A, Gould A, Gleeson L, Westbury H, Hiley L, Selvey L, Rodwell B.A morbillivirus has been isolated and added to an increasing list of emerging viral diseases. This virus caused an outbreak of fatal respiratory disease in horses and humans. Genetic analyses show it to be only distantly related to the classic morbilliviruses rinderpest, measles, and canine distemper. When seen by electron microscopy, viruses had 10- and 18-nanometer surface projections that gave them a "double-fringed" appearance. The virus induced syncytia that developed in the endothelium of blood vessels, particularly the lungs.
Petersen HH, Nielsen JP, Heegaard PM.The body's early defence in response to trauma, inflammation or infection, the acute phase response, is a complex set of systemic reactions seen shortly after exposure to a triggering event. One of the many components is an acute phase protein response in which increased hepatic synthesis leads to increased serum concentration of positive acute phase proteins. The serum concentration of these acute phase proteins returns to base levels when the triggering factor is no longer present. This paper provides a review of the acute phase proteins haptoglobin, C-reactive protein and serum amyloid A an...
Costa MC, Arroyo LG, Allen-Vercoe E, Stämpfli HR, Kim PT, Sturgeon A, Weese JS.The intestinal tract houses one of the richest and most complex microbial populations on the planet, and plays a critical role in health and a wide range of diseases. Limited studies using new sequencing technologies in horses are available. The objective of this study was to characterize the fecal microbiome of healthy horses and to compare the fecal microbiome of healthy horses to that of horses with undifferentiated colitis. A total of 195,748 sequences obtained from 6 healthy horses and 10 horses affected by undifferentiated colitis were analyzed. Firmicutes predominated (68%) among health...
den Boon JA, Snijder EJ, Chirnside ED, de Vries AA, Horzinek MC, Spaan WJ.The nucleotide sequence of the genome of equine arteritis virus (EAV) was determined from a set of overlapping cDNA clones and was found to contain eight open reading frames (ORFs). ORFs 2 through 7 are expressed from six 3'-coterminal subgenomic mRNAs, which are transcribed from the 3'-terminal quarter of the viral genome. A number of these ORFs are predicted to encode structural EAV proteins. The organization and expression of the 3' part of the EAV genome are remarkably similar to those of coronaviruses and toroviruses. The 5'-terminal three-quarters of the genome contain the putative EAV p...
Uilenberg G.The history of the genus Babesia is briefly outlined. The classical differences with the main other genus of non-pigment-forming hemoparasites, Theileria, are the absence of extra-erythrocytic multiplication (schizogony) in Babesia and the cycle in the vector tick, which includes transovarial transmission in Babesia but only transstadial transmission in Theileria. Also, the multiplication in the red cell of Babesia, by budding, most often results in two daughter cells (merozoites), while that of Theileria gives four merozoites, often as a Maltese cross. In particular this means that what is st...
McCoy AM.Osteoarthritis (OA) is unquestionably one of the most important chronic health issues in humans, affecting millions of individuals and costing billions of dollars annually. Despite widespread awareness of this disease and its devastating impact, the pathogenesis of early OA is not completely understood, hampering the development of effective tools for early diagnosis and disease-modifying therapeutics. Most human tissue available for study is obtained at the time of joint replacement, when OA lesions are end stage and little can be concluded about the factors that played a role in disease deve...
Balazs EA, Denlinger JL.Viscosupplementation is a new medical concept that has as its therapeutic goal the restoration of rheological homeostasis in pathological structures such as osteoarthritic joints. When the normal viscoelasticity of a solid tissue compartment or the elastoviscosity of a liquid tissue compartment is decreased under pathological conditions, normal function and regenerative processes are impaired. By introducing viscosupplementary devices, the normal rheological state of such compartments is restored or augmented. These devices stay in the tissue compartment for various periods of time, depending ...
Goldansaz SA, Guo AC, Sajed T, Steele MA, Plastow GS, Wishart DS.Metabolomics uses advanced analytical chemistry techniques to comprehensively measure large numbers of small molecule metabolites in cells, tissues and biofluids. The ability to rapidly detect and quantify hundreds or even thousands of metabolites within a single sample is helping scientists paint a far more complete picture of system-wide metabolism and biology. Metabolomics is also allowing researchers to focus on measuring the end-products of complex, hard-to-decipher genetic, epigenetic and environmental interactions. As a result, metabolomics has become an increasingly popular "omics" app...
Dubey JP, Desmonts G.SEROLOGICAL and parasitological surveys indicate that Toxoplasma gondii infection is widely prevalent in horses (Riemann et a! 1975). To study the pathogenesis of orally-induced toxoplasmosis, 13 equids aged between Aix months and 13 years (nine ponies, three horses and one mule) were each inoculated orally with 10,000 oocysts of the GT-I strain of TRondii. The equids were killed 33 to 476 days after inoculation and their tissues were bioassaycd for T gondit (Dubey 1985). Details of inoculation, housing, clinical response and parasitological and histological findings were previously reported (...
Selvey LA, Wells RM, McCormack JG, Ansford AJ, Murray K, Rogers RJ, Lavercombe PS, Selleck P, Sheridan JW.To describe the clinical and epidemiological features of an outbreak of a viral infection affecting humans and horses. Methods: Stables in Hendra, a suburb of Brisbane. Methods: Affected horses and humans, and at-risk human contacts. Results: A pregnant mare died two days after arrival from a paddock elsewhere in Brisbane. Eight to 11 days later, illness (depression, anorexia, fever, dyspnoea, ataxia, tachycardia, tachypnoea and nasal discharge) was reported among 17 other horses from the same or an adjoining stable. Fourteen horses died or were put down. Five and six days after the index mare...
Ching PK, de los Reyes VC, Sucaldito MN, Tayag E, Columna-Vingno AB, Malbas FF, Bolo GC, Sejvar JJ, Eagles D, Playford G, Dueger E, Kaku Y....During 2014, henipavirus infection caused severe illness among humans and horses in southern Philippines; fatality rates among humans were high. Horse-to-human and human-to-human transmission occurred. The most likely source of horse infection was fruit bats. Ongoing surveillance is needed for rapid diagnosis, risk factor investigation, control measure implementation, and further virus characterization.
Desquesnes M, Holzmuller P, Lai DH, Dargantes A, Lun ZR, Jittaplapong S.Trypanosoma evansi, the agent of "surra," is a salivarian trypanosome, originating from Africa. It is thought to derive from Trypanosoma brucei by deletion of the maxicircle kinetoplastic DNA (genetic material required for cyclical development in tsetse flies). It is mostly mechanically transmitted by tabanids and stomoxes, initially to camels, in sub-Saharan area. The disease spread from North Africa towards the Middle East, Turkey, India, up to 53° North in Russia, across all South-East Asia, down to Indonesia and the Philippines, and it was also introduced by the conquistadores into Latin ...
Puffer BA, Parent LJ, Wills JW, Montelaro RC.We have previously demonstrated that the Gag p9 protein of equine infectious anemia virus (EIAV) is functionally homologous with Rous sarcoma virus (RSV) p2b and human immunodeficiency virus type 1 (HIV-1) p6 in providing a critical late assembly function in RSV Gag-mediated budding from transfected COS-1 cells (L. J. Parent et al., J. Virol. 69:5455-5460, 1995). In light of the absence of amino acid sequence homology between EIAV p9 and the functional homologs of RSV and HIV-1, we have now designed an EIAV Gag-mediated budding assay to define the late assembly (L) domain peptide sequences con...
Woldehiwet Z.Anaplasma phagocytophilum is the recently designated name replacing three species of granulocytic bacteria, Ehrlichia phagocytophila, Ehrlichia equi and the agent of human granulocytic ehrlichiosis, after the recent reorganization of the families Rickettsiaceae and Anaplasmataceae in the order Rickettsiales. Tick-borne fever (TBF), which is caused by the prototype of A. phagocytophilum, was first described in 1932 in Scotland. A similar disease caused by a related granulocytic agent was first described in horses in the USA in 1969; this was followed by the description of two distinct granulocy...
McIlwraith CW, Frisbie DD, Kawcak CE.Osteoarthritis (OA) is an important cause of pain, disability and economic loss in humans, and is similarly important in the horse. Recent knowledge on post-traumatic OA has suggested opportunities for early intervention, but it is difficult to identify the appropriate time of these interventions. The horse provides two useful mechanisms to answer these questions: 1) extensive experience with clinical OA in horses; and 2) use of a consistently predictable model of OA that can help study early pathobiological events, define targets for therapeutic intervention and then test these putative thera...
Burbelo PD, Dubovi EJ, Simmonds P, Medina JL, Henriquez JA, Mishra N, Wagner J, Tokarz R, Cullen JM, Iadarola MJ, Rice CM, Lipkin WI, Kapoor A.Genetic and biological characterization of new hepaciviruses infecting animals contributes to our understanding of the ultimate origins of hepatitis C virus (HCV) infection in humans and dramatically enhances our ability to study its pathogenesis using tractable animal models. Animal homologs of HCV include a recently discovered canine hepacivirus (CHV) and GB virus B (GBV-B), both viruses with largely undetermined natural host ranges. Here we used a versatile serology-based approach to determine the natural host of the only known nonprimate hepacivirus (NPHV), CHV, which is also the closest p...
Weaver SC, Salas R, Rico-Hesse R, Ludwig GV, Oberste MS, Boshell J, Tesh RB.Venezuelan equine encephalomyelitis (VEE) virus has caused periodic epidemics among human beings and equines in Latin America from the 1920s to the early 1970s. The first major outbreak since 1973 occurred in Venezuela and Colombia during 1995, and involved an estimated 75,000 to 100,000 people. We report an epidemiological and virological investigation of this epidemic. Methods: Virus isolates were made in cell culture from human serum, human throat swabs, and brain tissue from aborted and stillborn human fetuses, as well as from horse brain tissue and pooled mosquito collections. Human sera ...
Rosengren Pielberg G, Golovko A, Sundström E, Curik I, Lennartsson J, Seltenhammer MH, Druml T, Binns M, Fitzsimmons C, Lindgren G, Sandberg K....In horses, graying with age is an autosomal dominant trait associated with a high incidence of melanoma and vitiligo-like depigmentation. Here we show that the Gray phenotype is caused by a 4.6-kb duplication in intron 6 of STX17 (syntaxin-17) that constitutes a cis-acting regulatory mutation. Both STX17 and the neighboring NR4A3 gene are overexpressed in melanomas from Gray horses. Gray horses carrying a loss-of-function mutation in ASIP (agouti signaling protein) had a higher incidence of melanoma, implying that increased melanocortin-1 receptor signaling promotes melanoma development in Gra...
Marasas WF, Kellerman TS, Gelderblom WC, Coetzer JA, Thiel PG, van der Lugt JJ.Each of two horses was dosed by stomach tube with culture material on maize of Fusarium moniliforme MRC 826. One horse developed severe hepatosis and mild oedema of the brain after 6 doses of 2.5 g of culture material/kg body mass/day in 7 days. The second horse, in a similar experiment but at a dosage rate of 1.25 g/kg/day, developed mild hepatosis and moderate oedema of the brain. In both animals the brain oedema was particularly noticeable in the medulla oblongata. The mycotoxin fumonisin B1 was extracted and purified from the culture material of F. moniliforme MRC, 826 which contained appr...
Ahern BJ, Parvizi J, Boston R, Schaer TP.Review the literature for single site cartilage defect research and evaluate the respective strengths and weaknesses of different preclinical animal models. Methods: A literature search for animal models evaluating single site cartilage defects was performed. Variables tabulated and analyzed included animal species, age and number, defect depth and diameter and study duration. Cluster analyses were then used to separate animals with only distal femoral defects into similar groups based on defect dimensions. Representative human studies were included allowing comparison of common clinical lesio...
MacDonald GH, Johnston RE.The initial steps of Venezuelan equine encephalitis virus (VEE) spread from inoculation in the skin to the draining lymph node have been characterized. By using green fluorescent protein and immunocytochemistry, dendritic cells in the draining lymph node were determined to be the primary target of VEE infection in the first 48 h following inoculation. VEE viral replicon particles, which can undergo only one round of infection, identified Langerhans cells to be the initial set of cells infected by VEE directly following inoculation. These cells are resident dendritic cells in the skin, which mi...
Saenz RA, Quinlivan M, Elton D, Macrae S, Blunden AS, Mumford JA, Daly JM, Digard P, Cullinane A, Grenfell BT, McCauley JW, Wood JL, Gog JR.A key question in pandemic influenza is the relative roles of innate immunity and target cell depletion in limiting primary infection and modulating pathology. Here, we model these interactions using detailed data from equine influenza virus infection, combining viral and immune (type I interferon) kinetics with estimates of cell depletion. The resulting dynamics indicate a powerful role for innate immunity in controlling the rapid peak in virus shedding. As a corollary, cells are much less depleted than suggested by a model of human influenza based only on virus-shedding data. We then explore...
O'Sullivan JD, Allworth AM, Paterson DL, Snow TM, Boots R, Gleeson LJ, Gould AR, Hyatt AD, Bradfield J.In September, 1994, an outbreak of severe respiratory disease affected 18 horses, their trainer, and a stablehand in Queensland, Australia. Fourteen horses and one human being died. A novel virus was isolated from those affected and named equine morbillivirus (EMV). We report a case of encephalitis caused by this virus. Results: A 35-year-old man from Queensland had a brief aseptic meningitic illness in August, 1994, shortly after caring for two horses that died from EMV infection and then assisting at their necropsies. He then suffered severe encephalitis 13 months later, characterised by unc...
