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.
Demyda-Peyrás S, Laseca N, Anaya G, Kij-Mitka B, Molina A, Karlau A, Valera M.Chromosomal abnormalities are largely associated with fertility impairments in the domestic horse. To date, over 600 cases of individuals carrying abnormal chromosome complements have been reported, making the domestic horse the species with the highest prevalence. However, studies analyzing the prevalence of chromosomal diseases in whole populations are scarce. We, therefore, employed a two-step molecular tool to screen and diagnose chromosomal abnormalities in a large population of 25,237 Pura Raza Español horses. Individuals were first screened using short tandem repeats parentage testing ...
Ludwig EK, Hallowell K, Womble M, O'Neil E.A 2-day-old Cleveland Bay colt was referred to the Equine Emergency Service of the Farm Animal and Equine Veterinary Medical Center at North Carolina State University's College of Veterinary Medicine for evaluation of decreased nursing behaviour and right hindlimb lameness of 2 days' duration. When assisted to stand, the foal was unable to extend either hindlimb or bear weight on the hindlimbs, the right patella was luxated laterally and unable to be reduced, and the foal assumed a crouched position. Stifle radiographs revealed minimal, heterogeneous, ill-defined ossification of both patellae....
Sandersen C, Dmitrovic P, Dupont J, Cesarini C, Guyot H, Serteyn D, Kirsch K.Different blood gas analyzers are used in equine practice. Every machine needs to be validated, as they have not been designed for use in horses. The aim of this study was to compare the newly marketed GEM5000 machine to the formerly validated epoc machine for blood gas analysis in horses. In this prospective, non-blinded, comparative laboratory analyzer study, 43 equine blood samples were analyzed on both analyzers and values were compared between the two machines via Lin's concordance analysis, Passing-Bablok regression analysis and Bland-Altman plots. Duplicate measurements were conducted o...
Nagy A, Dyson S.There are no detailed data on complications of sacroiliac (SI) joint region injections or on the variability of the methods and circumstances of injections among clinicians. Objective: To describe complications following diagnostic, therapeutic and combined SI joint region injections and the details of how these are routinely performed by a large number of clinicians. Methods: Cross-sectional questionnaire survey. Methods: Clinicians (members of American and European specialist colleges and veterinarians known to the authors), invited by email, who had performed ≥1 SI joint region injection,...
Simonin EM, Babasyan S, Tarsillo J, Wagner B.IgE+ plasmablasts develop following allergen exposure and B cell activation. They secrete IgE and therefore are directly linked to maintain the mechanisms of IgE-mediated allergies. Here, we show that the presence of IgE+ plasmablasts in peripheral blood not only coincides with clinical allergy, but also predicts the upcoming development of clinical disease. Using an equine model of naturally occurring allergy, we compared the timing of allergen exposure, arrival of IgE+ plasmablasts in peripheral blood, and onset of clinical disease. We found that IgE+ plasmablasts predict the development of ...
Peixoto Rabelo I, Barroco de Paula V, Carvalho Bustamante C, Santana AM, Gomes da Silva D, Baldassi AC, Canola PA, Araújo Valadão CA.Horses submitted to carbohydrate overload can develop laminitis due to changes in cecal pH and microbiota, followed by an increase in transmural absorption of luminal content, including bacterial toxins. In response to acute injury there is hepatic overproduction of several proteins known as acute phase proteins (APP). Few studies have evaluated protein fractionation to characterize the inflammatory response in acute laminitis. The aim of this study was to test the viability of an experimental model to induce acute laminitis, using a single carbohydrate overload, and the influence of a bufferi...
Kopper JJ.Equine rotavirus is one of the most common causes of infectious diarrhea in foals. Although the infection itself is self-limiting, the resulting diarrhea is due to multiple mechanisms and can be severe, requiring supportive care including fluid and electrolyte support. Prompt diagnosis is important for treatment and biosecurity decisions and can be achieved by several means. Prevention, while imperfect, currently relies on vaccination of pregnant mares before parturition, ingestion of adequate colostrum from vaccinated mares and biosecurity measures.
Sazmand A, Yavari M, Babaei M, Nourian A, Otranto D.Migration of Ascaris lumbricoides through the papilla of Vater in humans, and entry into the biliary tree, is well-recognised. Ascaris suum and Toxocara vitulorum have been recovered from the liver of swine and buffalo. We necropsied a Persian Kurdish filly at age 6 months, weighing ∼100 kg. Death evidently was caused by oleander (Nerium oleander) intoxication. An 8-cm adult male Parascaris was found at the lobar-left hepatic bile duct junction. We suggest that the nematode entered anteriorly into the hepatic tree, via the duodenum, major duodenal papilla, bile duct, left hepatic duct and f...
Oliver A, Conrado FO, Nolen-Walston R.Equine granulocytic anaplasmosis is a clinically significant and common disease of equids that has a broader prevalence than was once thought. The most common clinical signs include high fever and edema, with mild to mderate thrombocytopenia and lymphopenia typically noted on complete blood count. Subclinical cases are reported and many are self-limiting. Rare clinical presentations include neurologic disease, vasculitis, dysphagia, rhabdomyolysis, or bicavitary effusion. Most cases resolve rapidly with appropriate antimicrobial intervention.
Oliver A, Conrado FO, Nolen-Walston R.Equine granulocytic anaplasmosis is a clinically significant and common disease of equids that has a broader prevalence than was once thought. The most common clinical signs include high fever and edema, with mild to mderate thrombocytopenia and lymphopenia typically noted on complete blood count. Subclinical cases are reported and many are self-limiting. Rare clinical presentations include neurologic disease, vasculitis, dysphagia, rhabdomyolysis, or bicavitary effusion. Most cases resolve rapidly with appropriate antimicrobial intervention.
Taylor SD.Potomac horse fever (PHF) is a common cause of equine colitis in endemic areas. Until recently, the only causative agent known to cause PHF was Neorickettsia risticii. However, N. findlayensis has been isolated from affected horses. Horses typically become infected upon ingestion of Neorickettsia spp.-infected trematodes within aquatic insects. The most common clinical signs include diarrhea, fever, anorexia, lethargy and colic. The diagnostic test of choice for PHF is PCR of blood and feces. Tetracyclines remain an effective treatment. Supportive care, including fluid therapy, colloid ad...
Middlebrooks B, McCue P, Nelson B, May E, Divine C, Barton C, Conley A.Disorders of sexual development (DSD) are associated with atypical chromosomal, gonadal, or phenotypic sex. It is likely that the number of cases of DSD are underestimated in the equine population. Monorchidism in the horse is very rare. This case report describes the clinical assessment of a phenotypic mare with stallion-like behavior which led to the diagnosis of a DSD. A 4-year-old Quarter Horse mare presented in good body condition, with normal external genitalia for a mare, and normal mammary glands with two bilaterally symmetric teats. No uterus, cervix, or gonads were detected on transr...
Ruby RE, Janes JG.A variety of infectious agents including viral, bacterial, and fungal organisms can cause equine abortion and placentitis. Knowledge of normal anatomy and the common pattern distribution of different infectious agents will assist the practitioner in evaluating the fetus and/or placenta, collecting appropriate samples for further testing, and in some cases, forming a presumptive diagnosis. In all cases, it is recommended to confirm the diagnosis with molecular, serologic, or microbiological testing. If a causative agent can be identified, then appropriate biosecurity and vaccination measures ca...
Ogorek TJ, Golden JE.Venezuelan, western, and eastern equine encephalitic alphaviruses (VEEV, WEEV, and EEEV, respectively) are arboviruses that are highly pathogenic to equines and cause significant harm to infected humans. Currently, human alphavirus infection and the resulting diseases caused by them are unmitigated due to the absence of approved vaccines or therapeutics for general use. These circumstances, combined with the unpredictability of outbreaks-as exemplified by a 2019 EEE surge in the United States that claimed 19 patient lives-emphasize the risks posed by these viruses, especially for aerosolized V...
Melly V, Ortved KF, Manzi TJ, Richardson DW, Stefanovski D, Wulster KB.Increasing accessibility and advancements in computed tomographic (CT) imaging improve understanding of the contributors to poor performance in the Thoroughbred racehorse. Objective: To characterise an unreported site of tarsal subchondral bone injury (SBI) in Thoroughbred racehorses. Methods: Retrospective, cross-sectional analytical study. Methods: Tarsal CT scans of 108 horses were reviewed for evidence of SBI in the dorsodistolateral calcaneus (DDLC). Signalment, including age, breed, sex, and discipline of horses, was recorded. The association of DDLC SBI with Thoroughbred racehorse compa...
Veerasammy B, Gonzalez G, Báez-Ramos P, Schaaf CR, Stewart AS, Ludwig EK, McKinney-Aguirre C, Freund J, Robertson J, Gonzalez LM.Intestinal epithelial stem cells (ISC) are responsible for epithelial regeneration and are critical to the intestine's ability to regain barrier function following injury. Evaluating ISC biomarker expression in cases of small intestinal strangulation (SIS) may provide insight into clinical progression. Objective: Intestinal resection margins from cases of SIS were evaluated to determine if (1) evidence of injury could be identified using histomorphometry, (2) ISC biomarker expression was decreased in the proximal resection margin compared to control and distal resection margin, and (3) the ISC...
Ahedor B, Sivakumar T, Valinotti MFR, Otgonsuren D, Yokoyama N, Acosta TJ.Equine piroplasmosis (EP) is a tick-borne disease caused by Theileria equi and Babesia caballi in equids, including horses. EP has a global distribution and often leads to a significant socioeconomic impact on the equine industry. Infected animals remain as carriers and become a source of infection for tick vectors, thereby posing an immense challenge in the disease management. Therefore, detection of these carriers is crucial to assess the risk of transmission and to implement appropriate control measures in endemic countries. Paraguay is a tropical country where various tick-borne diseases a...
Costa da Silva RG, Mishra AP, Riggs CM, Doube M.To assess the capability of deep convolutional neural networks to classify anatomical location and projection from a series of 48 standard views of racehorse limbs. Unassigned: Radiographs ( = 9504) of horse limbs from image sets made for veterinary inspections by 10 independent veterinary clinics were used to train, validate and test (116, 40 and 42 radiographs, respectively) six deep learning architectures available as part of the open source machine learning framework PyTorch. The deep learning architectures with the best top-1 accuracy had the batch size further investigated. Unassigned: T...
Shaffer SK, Stover SM, Fyhrie DP.Focal bone lesions are often found prior to clinically relevant stress-fractures. Lesions are characterized by low bone volume fraction, low mineral density, and high levels of microdamage and are hypothesized to develop when bone tissue cannot sufficiently respond to damaging loading. It is difficult to determine how exercise drives the formation of these lesions because bone responds to mechanical loading and repairs damage. In this study, we derive steady-state rate constants for a compartment model of bone turnover using morphometric data from fractured and non-fractured racehorse proximal...
Chappell DE, Barnett DC, James K, Craig B, Bain F, Gaughan E, Schneider C, Vaala W, Barnum SM, Pusterla N.A voluntary upper respiratory biosurveillance program in the USA received 9740 nasal swab submissions during the years 2008-2021 from 333 veterinarians and veterinary clinics. The nasal swabs were submitted for qPCR testing for six common upper respiratory pathogens:equine influenza virus (EIV), equine herpesvirus-1 (EHV-1), equine herpesvirus-4 (EHV-4), subspecies (), equine rhinitis A virus (ERAV), and equine rhinitis B virus (ERBV). Additional testing was performed for equine gamma herpesvirus-2 (EHV-2) and equine gamma herpesvirus-5 (EHV-5) and the results are reported. Basic frequency s...
Cullinane A, Garvey M, Walsh C, Gibbons J, Creighton A.The association between poor performance and respiratory disease in Thoroughbred racehorses that do not have a structural abnormality of the respiratory tract, is often based on anecdotal evidence. The objective of this scoping review was to examine the scientific evidence for such associations. Publications were selected based on a search of three databases (PubMed, Scopus, and CAB Direct), in English and without date restriction, followed by a screening process to exclude non-relevant papers, duplicates, and reviews. This process identified 996 publications of which 20 were analysed using th...
de Almeida Campos AC, Cicolo S, de Oliveira CM, Molina CV, Navas-Suárez PE, Poltronieri Dos Santos T, da Silveira VB, Barbosa CM, Baccarin RYA....Equid herpesvirus (EHV) commonly affects horses causing neurologic and respiratory symptoms beside spontaneous abortions, meaning huge economic losses for equine industry worldwide. In foals, the virus can facilitate secondary infections by Rhodococcus equi, important in morbidity and mortality in equines. A total of five genotypes of EHV were previously described in Brazil including EHV-1, EHV-2, EHV-3, EHV-4, and EHV-5. EHV-2 genotype had only been previously described in Brazil in asymptomatic animals. We report the investigation of the dead of 11 foals in Middle-west region of Brazil showi...
Labbe KA, Allshouse KA, Gilmour LJ, Arnold CE, Whitfield-Cargile CM, Griffin CE.Sinusitis is a common disease of horses yet there are a limited number of reports in the literature that describe the prevalence of infraorbital canal (IOC) pathology and headshaking behaviour in horses diagnosed specifically with primary sinusitis and secondary dental sinusitis. Given the impact that these behaviours can have on horses' intended athletic use, investigation is warranted. Objective: To determine the occurrence of IOC pathology in horses with concurrent primary or secondary dental sinusitis based on computed tomography (CT) findings and to assess whether the frequency of headsha...
Lv S, Zhang Y, Zhang Z, Meng S, Pu Y, Liu X, Liu L, Ma Y, Liu W, Jiang L.The gut microbiomes of equine are plentiful and intricate, which plays an important part in the growth. However, there is a relative lack of information on the microbial diversity in the pony's gut. Unassigned: In this article, 118 fecal samples from DeBa pony, NiQi pony and GuZh horse were studied by 16S rRNA amplicon sequencing. Unassigned: Diversity analysis was used to determine the difference of gut microbiota composition among different breeds. Alpha diversity analysis showed that the gut microbiota of NiQi ponies were abundant and various. Beta diversity analysis showed that the microor...
Dobiáš R, Jahn P, Tóthová K, Dobešová O, Višňovská D, Patil R, Škríba A, Jaworská P, Škorič M, Podojil L, Kantorová M, Mrázek J....Invasive pulmonary aspergillosis (IPA) may be a rare cause of granulomatous pneumonia in horses. The mortality of IPA is almost 100%; direct diagnostic tools in horses are needed. Bronchoalveolar lavage fluid (BALF) and serum samples were collected from 18 horses, including individuals suffering from IPA (n = 1), equine asthma (EA, n = 12), and 5 healthy controls. Serum samples were collected from another 6 healthy controls. Samples of BALF (n = 18) were analyzed for spp. DNA, fungal galactomannan (GM), ferricrocin (Fc), triacetylfusarinin C (TafC), and gliotoxin (Gtx). Analysis of 24 serum s...
Quattrini C, Scalco R, Vernau W, Dini P, Aleman M.Cerebrospinal fluid (CSF) is highly labile and delayed processing might alter results of analysis. Objective: To determine the effects of time and addition of autologous serum on cytological evaluation of CSF. Methods: Ten client-owned adult horses requiring euthanasia. Methods: Prospective study. Serum and CSF were collected from each horse before and within 10 minutes after euthanasia. CSF samples were divided into 15 aliquots (2 mL each); 1 aliquot was submitted for routine CSF analysis within 60 minutes of collection. Four drops of autologous serum were added to 7 of the aliquots, and ...
Miglinci L, Reicher P, Nell B, Koch M, Jindra C, Brandt S.Squamous cell carcinoma (SCC) seriously compromises the health and welfare of affected horses. Although robust evidence points to equine papillomavirus type 2 (EcPV2) causing genital lesions, the etiopathogenesis of equine SCC is still poorly understood. We screened a series of SCCs from the head-and-neck (HN), (peri-)ocular and genital region, and site-matched controls for the presence of EcPV2-5 and herpesvirus DNA using type-specific EcPV PCR, and consensus nested herpesvirus PCR followed by sequencing. EcPV2 DNA was detected in 45.5% of HN lesions, 8.3% of (peri-)ocular SCCs, and 100% of g...
Fjordbakk CT, Marques-Smith P.Interpretation of patellar ligament (PL) ultrasonography may be difficult, as hypoechoic or heterogenous echogenicity are common findings. Verifying suspected disease of equine PLs by histopathology is also problematic as descriptions of normal PL vascularity and histology are scarce. The current study describes the PL and infrapatellar fat pad (IFP) vascular pattern from computed tomography scans of barium perfused normal equine specimens (n = 8; age 10 days to 18 years), as well as routine histology to serve as a reference for future investigations into PL pathology and IFP disease. Re...
Gosai F, Gosai N.Strangles is a contagious upper respiratory tract infection primarily affecting equines. It is rare disease with zoonotic transmission. It is caused by the bacterium, . We present the rare case of strangles in an elderly patient complicated by bacteraemia, osteomyelitis and native valve endocarditis. The patient was treated successfully with appropriate antibiotics and no surgical intervention was needed. In an age of accelerated emerging zoonosis, this is an important entity clinicians should be aware of to prevent delay in diagnosis and poor outcome. Conclusions: Strangles is a disease of eq...
Pepys MB, Baltz ML, Tennent GA, Kent J, Ousey J, Rossdale PD.A sensitive and precise immunoassay for equine serum amyloid A protein (SAA) was established and used to determine, for the first time, the circulating concentration of this protein in health and disease. As in other species, equine SAA was present only at trace levels in healthy animals but behaved as an extremely sensitive and rapidly responding acute phase reactant following most forms of tissue injury, infection and inflammation, objectively reflecting the extent and activity of disease. Measurements of SAA should make a significant contribution to diagnosis and management of viral and bac...
LeBlanc MM, Magsig J, Stromberg AJ.Low-volume uterine flush (n=401) was performed in 308 infertile mares to diagnose endometritis. Mares evaluated were either barren after three or more breedings or had two or more unsuccessful embryo recovery attempts during consecutive cycles. Culture results were compared with cytological and histological findings, efflux clarity and pH to substantiate that the micro-organisms recovered were truly pathogens. Cytological specimens were evaluated for presence of epithelial and inflammatory cells, bacteria, yeast and debris. Endometrial biopsies (n=110) were examined for the presence of neutrop...
Oaks JL, McGuire TC, Ulibarri C, Crawford TB.The equine infectious anemia virus (EIAV) often results in lifelong subclinical infection following early episodes of clinical disease. To identify the cellular reservoirs of EIAV during subclinical infection, horses were infected with EIAV and allowed to develop subclinical infections. Horses with acute disease served as a basis for comparison. The tissue distribution, replication status, location of infected cells, and viral load were characterized by PCR for proviral DNA and reverse transcriptase PCR for viral RNA, in situ hybridization, and in situ PCR. Proviral DNA was widespread in tissu...
Johns IC, Baxter K, Booler H, Hicks C, Menzies-Gow N.To describe the bacterial and fungal flora of the normal conjunctiva of horses in the UK; to determine the effect of horse age, sex, geographic location, and housing on this flora; and to determine the most appropriate antimicrobial drug(s) for prophylactic treatment of corneal ulcers. Methods: A total of 60 adult healthy horses were studied. Methods: Swabs of the conjunctiva were obtained from 60 horses housed in two locations within the UK. Specimens were cultured for aerobic bacteria and fungi, and sensitivity against six ophthalmic antimicrobials assessed. The effect of age, sex, location ...
Arroyo LG, Rossi L, Santos BP, Gomez DE, Surette MG, Costa MC.The aim of this study was to compare the mucosal and luminal content microbiota of the cecum and colon of healthy and diarrheic horses. Marked differences in the richness and in the community composition between the mucosal and luminal microbiota of the cecum and large colon of horses with colitis were observed. Microbial dysbiosis occurs in horses with colitis at different levels of the intestinal tract, and microbiota composition is different between the mucosa and luminal content of diarrheic horses. The changes in some key taxa associated with dysbiosis in the equine intestinal microbiota,...
Li F, Puffer BA, Montelaro RC.Equine infectious anemia virus (EIAV) contains the simplest genome among lentiviruses in that it encodes only three putative regulatory genes (S1, S2, S3) in addition to the canonical gag, pol, and env genes, presumably reflecting its limited tropism to cells of monocyte/macrophage lineage. Tat and Rev functions have been assigned to S1 and S3, respectively, but the specific function for the S2 gene has yet to be determined. Thus, the function of S2 in virus replication in vitro was investigated by using an infectious molecular viral clone, EIAVUK. Various EIAVUK mutants lacking S2 were constr...
Lavoie-Lamoureux A, Leclere M, Lemos K, Wagner B, Lavoie JP.Systemic inflammation in horses with heaves is poorly characterized. Objective: To assess acute phase proteins (APP) and inflammatory cytokine profiles in serum of healthy horses and horses with heaves. Methods: Six healthy horses and 6 heaves-affected horses belonging to the University of Montreal. Methods: Prospective, observational study. Healthy and heaves-affected control horses were exposed to a 30-day natural challenge with hay and straw to induce clinical exacerbation of heaves. Serum samples were obtained by venipuncture before (T0) as well as after 7 (T7) and 30 days (T30) of stablin...
Johnston K, Holcombe SJ, Hauptman JG.To determine the relationship between plasma lactate concentration and colonic viability and survival in horses with >or=360 degrees volvulus of the ascending colon. Methods: Retrospective study. Methods: Horses (n=73) with >or=360 degrees volvulus of the ascending colon. Methods: Medical records (January 2000-November 2005) of all horses examined for colic at Michigan State University Veterinary Teaching Hospital were reviewed. Horses were included only if plasma lactate concentration was measured preoperatively and a diagnosis of >or=360 degrees volvulus of the ascending colon was c...
Tomlinson JE, Jager M, Struzyna A, Laverack M, Fortier LA, Dubovi E, Foil LD, Burbelo PD, Divers TJ, Van de Walle GR.Equine parvovirus-hepatitis (EqPV-H) has recently been associated with cases of Theiler's disease, a form of fulminant hepatic necrosis in horses. To assess whether EqPV-H is the cause of Theiler's disease, we first demonstrated hepatotropism by PCR on tissues from acutely infected horses. We then experimentally inoculated horses with EqPV-H and 8 of 10 horses developed hepatitis. One horse showed clinical signs of liver failure. The onset of hepatitis was temporally associated with seroconversion and a decline in viremia. Liver histology and in situ hybridization showed lymphocytic infiltrate...
Sykes BW, Sykes KM, Hallowell GD.A previous study demonstrated that a dose effect between 1.6 and 4.0 mg/kg bwt of omeprazole per os s.i.d. is present in the treatment of equine gastric ulceration. In the same study, healing of glandular ulceration appeared inferior to healing of squamous ulceration. However, several limitations were recognised in that study and further investigation is warranted. Objective: To further investigate the presence of a dose relationship in the treatment of gastric ulceration under conditions that may favour omeprazole efficacy such as administration prior to exercise and after a brief fast, and...
McGorum BC, Ellison J, Cullen RT.The concentrations of total and respirable airborne endotoxin in the breathing zone of a pony in 3 different management systems, on 8 occasions, are reported. Airborne endotoxin concentrations in all 3 systems were lower than those reported for many other agricultural environments. However, total airborne endotoxin concentrations in many of the conventional stables exceeded those which can induce pulmonary inflammation and bronchial hyper-responsiveness in normal human subjects, and exceeded those which can induce bronchoconstriction in humans with pre-existing pulmonary inflammation. Therefor...
Wang H, Liu KJ, Sun YH, Cui LY, Meng X, Jiang GM, Zhao FW, Li JJ.Salmonella enterica subspecies enterica serovar abortus equi (S. abortus equi) is well known as the aetiological agent of equine abortion. However, abortion caused by S. abortus equi has not been previously described in donkeys. Objective: To investigate whether S. abortus equi was correlated with an abortion outbreak consisting of 61 abortions. Methods: Investigation of the clinical cases using pathoanatomical, bacteriological, serological and molecular approaches. Methods: Autopsies on nine aborted foetuses were performed. Tissue specimens from seven aborted foetuses and two mares were cu...
Rosa R, Costa EA, Marques RE, Oliveira TS, Furtini R, Bomfim MR, Teixeira MM, Paixão TA, Santos RL.St. Louis encephalitis virus (SLEV) is a causative agent of encephalitis in humans in the Western hemisphere. SLEV is a positive-sense RNA virus that belongs to the Flavivirus genus, which includes West Nile encephalitis virus, Japanese encephalitis virus, Dengue virus and other medically important viruses. Recently, we isolated a SLEV strain from the brain of a horse with neurological signs in the countryside of Minas Gerais, Brazil. The SLEV isolation was confirmed by reverse-transcription RT-PCR and sequencing of the E protein gene. Virus identity was also confirmed by indirect immunofluore...
Hussey GS, Goehring LS, Lunn DP, Hussey SB, Huang T, Osterrieder N, Powell C, Hand J, Holz C, Slater J.Equine herpesvirus myeloencephalitis (EHM) remains one of the most devastating manifestations of equine herpesvirus type 1 (EHV-1) infection but our understanding of its pathogenesis remains rudimentary, partly because of a lack of adequate experimental models. EHV-1 infection of the ocular vasculature may offer an alternative model as EHV-1-induced chorioretinopathy appears to occur in a significant number of horses, and the pathogenesis of EHM and ocular EHV-1 may be similar. To investigate the potential of ocular EHV-1 as a model for EHM, and to determine the frequency of ocular EHV-1, our ...
Camacho AT, Guitian FJ, Pallas E, Gestal JJ, Olmeda AS, Habela MA, Telford SR, Spielman A.The control of equine piroplasmosis is becoming increasingly important to maintain the international market open to the horse industry. The purpose of this study was to demonstrate the occurrence of equine piroplasmosis (Theileria equi and Babesia caballi) in Galicia, north-west Spain, and to compare haematological and serum biochemistry parameters between non-parasitaemic horses and horses parasitaemic with T. equi and B. caballi. Sixty serum samples (control group) were taken from healthy horses pastured on two farms, and examined for evidence of equine T. equi and B. caballi infection by in...
Bochnia M, Ziegler J, Sander J, Uhlig A, Schaefer S, Vollstedt S, Glatter M, Abel S, Recknagel S, Schusser GF, Wensch-Dorendorf M, Zeyner A.Hypoglycin A (HGA) in seeds of Acer spp. is suspected to cause seasonal pasture myopathy in North America and equine atypical myopathy (AM) in Europe, fatal diseases in horses on pasture. In previous studies, this suspicion was substantiated by the correlation of seed HGA content with the concentrations of toxic metabolites in urine and serum (MCPA-conjugates) of affected horses. However, seed sampling was conducted after rather than during an outbreak of the disease. The aim of this study was to further confirm the causality between HGA occurrence and disease outbreak by seed sampling during ...
Knowles DP, Perryman LE, Goff WL, Miller CD, Harrington RD, Gorham JR.Babesiosis is a tick-borne hemoparasitic disease affecting horses worldwide. To investigate mechanisms of immunity to this parasite, the antibody response of infected horses to Babesia equi merozoite proteins was evaluated. Immunoprecipitation of B. equi merozoite antigens with sera from infected horses revealed 11 major proteins of 210, 144, 108, 88, 70, 56, 44, 36, 34, 28, and 25 kDa. Monoclonal antibody (MAb) 36/133.97, which binds to live merozoites, immunoprecipitated proteins of 44, 36, 34, and 28 kDa. When immunoprecipitations were performed with in vitro translation products of merozoi...
Amaya M, Keck F, Lindquist M, Voss K, Scavone L, Kehn-Hall K, Roberts B, Bailey C, Schmaljohn C, Narayanan A.Many viruses have been implicated in utilizing or modulating the Ubiquitin Proteasome System (UPS) to enhance viral multiplication and/or to sustain a persistent infection. The mosquito-borne Venezuelan equine encephalitis virus (VEEV) belongs to the Togaviridae family and is an important biodefense pathogen and select agent. There are currently no approved vaccines or therapies for VEEV infections; therefore, it is imperative to identify novel targets for therapeutic development. We hypothesized that a functional UPS is required for efficient VEEV multiplication. We have shown that at non-tox...
Finley MR, Li Y, Hua F, Lillich J, Mitchell KE, Ganta S, Gilmour RF, Freeman LC.In dogs and in humans, potassium channels formed by ether-a-go-go-related gene 1 protein ERG1 (KCNH2) and KCNQ1 alpha-subunits, in association with KCNE beta-subunits, play a role in normal repolarization and may contribute to abnormal repolarization associated with long QT syndrome (LQTS). The molecular basis of repolarization in horse heart is unknown, although horses exhibit common cardiac arrhythmias and may receive drugs that induce LQTS. In horse heart, we have used immunoblotting and immunostaining to demonstrate the expression of ERG1, KCNQ1, KCNE1, and KCNE3 proteins and RT-PCR to det...
Allen G, Yeargan M, Costa LR, Cross R.An experimental system that permits sensitive and reproducible detection of equine herpesvirus 1 (EHV-1)-specific cytotoxic T-lymphocyte (CTL) activity in the horse was developed. Peripheral blood mononuclear cells (PBMC) collected from immune horses were restimulated in vitro by culture with live EHV-1. Cytotoxic activity against virus-infected, pokeweed mitogen-stimulated lymphoblast targets was assessed in a 4-h 51Cr release assay. The optimal conditions for in vitro stimulation of equine memory CTLs and for preparation of EHV-1-infected target cells expressing viral antigens were systemati...
Schöniger S, Schoon HA.Mares are seasonally polyestric. The breeding season in spring and summer and the winter anestrus are flanked by transitional periods. Endometrial diseases are a frequent cause of subfertility and have an economic impact on the horse breeding industry. They include different forms of endometrosis, endometritis, glandular maldifferentiation, and angiosis. Except for suppurative endometritis, these are subclinical and can only be diagnosed by the microscopic examination of an endometrial biopsy. Endometrosis is characterized by periglandular fibrosis and nonsuppurative endometritis by stromal in...
Freeman K, Woods E, Welsby S, Percival SL, Cochrane CA.Evidence of biofilms in human chronic wounds are thought to be responsible for preventing healing in a timely manner. However, biofilm evidence in horse wounds has not yet been documented. Consequently, this study aimed to determine whether biofilms could be detected in wounds, and to investigate the microbiology of chronic wounds in horses. Prior to analysis, wound surfaces were irrigated with 5 mL of sterile saline to remove debris. All wounds were swabbed twice (1 cm2 area) using sterile cotton-tipped swabs. In addition to this, 2 tissue biopsies were taken to investigate evidence of biofil...
Malalana F, Stylianides A, McGowan C.Equine recurrent uveitis (ERU) is a spontaneous disease characterised by repeated episodes of intraocular inflammation. The epidemiology of ERU has not been fully elucidated, but the condition appears to be much more common in horses than is recurrent uveitis in humans, especially in certain breeds and geographical regions. Both humans and horses show a similarly altered immune response and a marked autoimmune response as the primary disease pathophysiology. However, an inciting cause is not always clear. Potential inciting factors in horses include microbial agents such as Leptospira spp. Mic...
Pusterla N, Vin R, Leutenegger C, Mittel LD, Divers TJ.Equine coronavirus (ECoV) is an emerging virus associated clinically and epidemiologically with fever, depression, anorexia and less frequently colic and diarrhoea in adult horses. Sporadic cases and outbreaks have been reported with increased frequency since 2010 from Japan, the USA and more recently from Europe. A faeco-oral transmission route is suspected and clinical or asymptomatic infected horses appear to be responsible for direct and indirect transmission of ECoV. A presumptive clinical diagnosis of ECoV infection may be suggested by clinical presentation, haematological abnormalities ...
Deregt D, de Vries AA, Raamsman MJ, Elmgren LD, Rottier PJ.Monoclonal antibodies (MAbs) to equine arteritis virus (EAV) proteins were produced and characterized. The protein specificities of eight MAbs were determined definitively by immunoprecipitation of EAV proteins expressed from vaccinia virus recombinants (VVRs). Included were two new VVRs produced for this study, expressing the M and the GL proteins, respectively. Three MAbs were determined to be N-specific and five MAbs recognized the GL protein. One GL-specific MAb, 17F5, of the IgA class, efficiently neutralized EAV infectivity. In competitive binding assays (CBAs), the N-specific MAbs defin...
Adney DR, Brown VR, Porter SM, Bielefeldt-Ohmann H, Hartwig AE, Bowen RA.The Middle East respiratory syndrome coronavirus (MERS-CoV) was first recognized in 2012 and can cause severe disease in infected humans. Dromedary camels are the reservoir for the virus, although, other than nasal discharge, these animals do not display any overt clinical disease. Data from in vitro experiments suggest that other livestock such as sheep, goats, and horses might also contribute to viral transmission, although field data has not identified any seropositive animals. In order to understand if these animals could be infected, we challenged young goats and horses and adult sheep wi...
Gildea S, Fitzpatrick DA, Cullinane A.Outbreaks of equine influenza (EI) in endemic populations cause disruption and economic loss. Objective: To identify (i) factors involved in the spread of EI (ii) virus strains responsible for outbreaks (iii) single radial haemolysis (SRH) antibody levels correlating with protection against current virus strains (iv) evidence of vaccination breakdown. Methods: RT-PCR, virus isolation and SRH were carried out on nasopharyngeal swabs and blood samples collected from horses, ponies and donkeys on affected premises. Data relating to 629 samples from 135 equidae were analysed. Conclusions: Outbreak...
Bogaert L, Martens A, Van Poucke M, Ducatelle R, De Cock H, Dewulf J, De Baere C, Peelman L, Gasthuys F.Bovine papillomavirus (BPV), the causative agent of papillomas in cattle, has been shown to play a major role in the pathogenesis of equine sarcoids in horses. BPV has also been detected occasionally in normal equine skin. In this study, presence and activity of BPV in normal skin and peripheral blood of 4 groups of horses were evaluated: sarcoid-affected horses, horses living in contact with sarcoid-affected horses, horses living in contact with papilloma-affected cattle and control horses. From each horse, 3 samples on 4 locations were collected: a swab of the intact skin surface and both a ...
Fetene E, Leta S, Regassa F, Büscher P.Trypanosomosis caused by Trypanosoma vivax is one of the diseases threatening the health and productivity of livestock in Africa and Latin America. Trypanosoma vivax is mainly transmitted by tsetse flies; however, the parasite has also acquired the ability to be transmitted mechanically by hematophagous dipterans. Understanding its distribution, host range and prevalence is a key step in local and global efforts to control the disease. Methods: The study was conducted according to the methodological recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRIS...
Castagnetti C, Pirrone A, Mariella J, Mari G.The use of blood lactate concentration as an indicator of prognosis and disease severity has become a common practice in equine medicine, especially with the validation of handheld analyzers. However, few authors described lactate concentration in critically ill foals, and there are no published studies about the use of handheld analyzers in neonatal foals. In this study, for the first time in the equine neonate, we validated the Lactate Scout analyzer, both in healthy and in critically ill foals. The study also describes the normal range for blood lactate in 26 healthy neonatal foals during t...
