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.
Valcek A, Sismova P, Nesporova K, Overballe-Petersen S, Bitar I, Jamborova I, Kant A, Hrabak J, Wagenaar JA, Madec JY, Damborg P, van Duijkeren E....The relatedness of the equine-associated ST1250 and its single- and double-locus variants (ST1250-SLV/DLV), obtained from horses in Europe, was studied by comparative genome analysis. A total of 54 isolates of ST1250 and ST1250-SLV/DLV from healthy and hospitalized horses across Europe [Czech Republic (n=23), the Netherlands (n=18), Germany (n=9), Denmark (n=3) and France (n=1)] from 2008-2017 were subjected to whole-genome sequencing. An additional 25 draft genome assemblies of ST1250 and ST1250-SLV/DLV were obtained from the public databases. The isolates were compared for genomic feature...
Malbon AJ, Dürrwald R, Kolodziejek J, Nowotny N, Kobera R, Pöhle D, Muluneh A, Dervas E, Cebra C, Steffen F, Paternoster G, Gerspach C, Hilbe M.Borna disease (BD), a frequently fatal neurologic disorder caused by Borna disease virus 1 (BoDV-1), has been observed for decades in horses, sheep, and other mammals in certain regions of Europe. The bicoloured white-toothed shrew (Crocidura leucodon) was identified as a persistently infected species involved in virus transmission. Recently, BoDV-1 attracted attention as a cause of fatal encephalitis in humans. Here, we report investigations on BoDV-1-infected llamas from a farm in a BD endemic area of Switzerland, and alpacas from holdings in a region of Germany where BD was last seen in the...
Zsoldos RR, Khayatzadeh N, Soelkner J, Schroeder U, Hahn C, Licka TF.Type 1 polysaccharide storage myopathy caused by genetic mutation in the glycogen synthase 1 gene is present in many breeds including the Noriker and Haflinger horses. In humans, EMG has already been used to document changes in the muscle activity patterns of patients affected by human glycogen storage disorders. Therefore, the aim of the present study was to describe gluteus muscle activity with surface electromyography (sEMG) in Haflinger and Noriker horses with known GYS1 mutation status during walk and trot. Thirty-two horses (11 Haflinger and 21 Noriker horses) with homozygous non-affecte...
Nath LC, Elliott AD, Weir J, Curl P, Rosanowski SM, Franklin S.Atrial fibrillation (AF) impacts performance and horse and jockey safety. Understanding the outcomes of AF identified postrace will better inform regulatory policy. Objective: To investigate the outcomes after episodes of AF identified postrace and determine whether affected horses are at increased risk of additional episodes compared to the general racing population. Methods: Total of 4684 Thoroughbred racehorses. Methods: Race records for Thoroughbred horses racing in Hong Kong from 2007 to 2017 were reviewed. Horses that performed below expectation were examined by cardiac auscultation and ...
Conrado FO, Beatty SSK.Fluid analysis is an important part of the diagnostic work-up of equine patients presenting with disorders of the nervous system, musculoskeletal system, and abdominal cavity. Proper specimen handling and processing are paramount for complete and accurate interpretation of fluid samples. Normal cerebrospinal fluid is a low-cellularity, low-protein fluid requiring specific sample handling to ensure accurate results. Joint and abdominal fluid analyses are completed in practice or submitted for analysis to a reference laboratory. This article discusses fluid sample handling and processing conside...
de Barros AMC, Silva AFR, Zibordi M, Spagnolo JD, Corrêa RR, Belli CB, de Camargo MM.Scoring models are useful tools that guide the attending clinician in gauging the severity of disease evolution and in evaluating the efficacy of treatment. There are few tools available with this purpose for the non-human patient, including horses. We aimed (i) to adapt the simplified acute physiology score 3 (SAPS-3) model for the equine species, reaching a margin of accuracy greater than 75% in the calculation of the probability of survival/death and (ii) to build a decision tree that helps the attending veterinarian in assessment of the clinical evolution of the equine patient. Methods: Fr...
Doerksen T, Bird E, Henningson J, Palinski R.Here, we report the near-complete genome sequences of vesicular stomatitis virus (VSV) serotype Indiana isolates from the 2020 U.S. outbreak. The sequences were obtained from swabs collected from Kansas horses in July and August. The four genome sequences help improve our understanding of VSV outbreak dynamics in the United States.
Rynhoud H, Meler E, Gibson JS, Price R, Maguire T, Farry T, Bennett E, Hartono J, Soares Magalhães RJ.To detect methicillin resistant Staphylococcus aureus (MRSA) and S. pseudintermedius (MRSP) swab samples were collected from dogs, cats and horses from South East Queensland (SE QLD). MRSP carriage in dogs was 8.7% and no MRSP was isolated from cats and horses; no MRSA was isolated. Risk factors for carriage included previous hospitalisation, previous bacterial infection, consultation type, average precipitation, and human population density. The probability of MRSP carriage was highest in Brisbane city, Sunshine Coast and Gympie. This suggests that MRSP carriage in dog populations from SE QLD...
Fedorka CE, Ball BA, Walker OF, McCormick ME, Scoggin KE, Kennedy LA, Squires EL, Troedsson MHT.Equine abortions are attributed to both infectious and noninfectious causes. Clinical extrapolations are often made from the experimental model for ascending placentitis towards other causes of fetal compromise, including various markers of inflammation, including the cytokines IL-2, 5, IL-6, IL-10, IFNγ, and TNF. It is unknown if these cytokine changes are noted under field conditions, or if they increase preceding other pregnancy related complications. To assess this, Thoroughbred mares (n = 702) had weekly blood obtained beginning in December 2013 and continuing until parturition. Fet...
Atiba A, Ghazy A, Hamad MH.Cutaneous pythiosis in horses is a chronic ulcerative granulomatous disease caused by the oomycete Pythium insidiosum. Objective: The objective of the present study was to evaluate the response of cutaneous pythiosis in horses to surgical excision and topical dimethyl sulphoxide (DMSO). Methods: Thirty horses were presented clinically with pruritus, fistulae discharging serosanguineous fluid, and output kunkers in different body areas (limb, abdomen, neck, and face). The clinical diagnosis was confirmed by isolation of the causative agent and histopathology. All animals were treated by surgica...
Elschner MC, Melzer F, Singha H, Muhammad S, Gardner I, Neubauer H.Glanders, caused by Burkholderia (B.) mallei is a notifiable zoonotic disease in equidae. For international trade and movement of equids, certificates of negative serological test results for antibodies against B. mallei are required. To date, the complement fixation test (CFT) is the mandatory test to issue these health certificates. The CFT is difficult to standardize and, due to its poor specificity, often leads to false-positive reactions resulting in trade restrictions with considerable financial consequences. In the present study, the new ID Screen Glanders Double Antigen Multispecies EL...
Darby S, Sanchez LC, Mallicote MF, House AM, Plummer CE, Nadruz V, Benmoha RH, Roberts SM, Derendorf H, Silva-Sanchez C, Claire J, MacKay RJ.Creeping indigo (Indigofera spicata) toxicosis is an emerging problem among horses in Florida and bordering states. Objective: To quantify the putative toxins l-indospicine (IND) and 3-nitropropionic acid (NPA) in creeping indigo collected from multiple sites and to measure plasma toxin concentrations in ponies fed creeping indigo and horses with presumptive creeping indigo toxicosis. Methods: Experimental descriptive study with descriptive observational field investigation. Methods: Air-dried creeping indigo was assayed for IND and NPA content. Five ponies were fed chopped creeping indigo con...
Tucker R, Hall YS, Hughes TK, Parker RA.Computed tomography (CT) imaging of the cervical spine of mature horses under general anaesthesia is becoming increasingly accessible. Osteochondral fragmentation (OF) of the cervical articular process joints (APJs) has been identified on CT imaging; the prevalence, clinical features and significance of this finding are currently unknown. Objective: To describe the prevalence and clinical features of a population of horses with CT evidence of OF within the cervical APJs. Methods: Retrospective, descriptive case series. Methods: The study population consisted of all horses undergoing CT imaging...
Lindåse S, Nostell K, Bergsten P, Forslund A, Bröjer J.Proxies are mathematical calculations based on fasting glucose and/or insulin concentrations developed to allow prediction of insulin sensitivity (IS) and β-cell response. These proxies have not been evaluated in horses with insulin dysregulation. The first objective of this study was to evaluate how fasting insulin (FI) and proxies for IS (1/Insulin, reciprocal of the square root of insulin (RISQI) and the quantitative insulin sensitivity check index (QUICKI)) and β-cell response (the modified insulin-to-glucose ratio (MIRG) and the homeostatic model assessment of β-cell function (HOMA-β)...
Derham AM, Schumacher J, O' Leary JM, Kelly G, Hahn CN.Impinging/overriding dorsal spinous processes (DSPs) of the thoracolumbar vertebrae are a common cause of poor performance in horses. In the last five decades, numerous surgical treatments have been reported on, from transverse transection of the affected DSPs, and endoscopic resection of the affected DSPs, to transection of the interspinous ligament. Until recently, cosmetic outcomes have been reported as good to excellent in studies. However, a previously unreported complication of neurogenic atrophy of the contralateral epaxial muscle following desmotomy of the interspinous ligament has bee...
Wimmer-Scherr C, Taminiau B, Renaud B, van Loon G, Palmers K, Votion D, Amory H, Daube G, Cesarini C.Equine atypical myopathy (AM) is caused by hypoglycin A (HGA) and methylenecyclopropylglycine (MCPG) intoxication resulting from the ingestion of seeds or seedlings of some Acer tree species. Interestingly, not all horses pasturing in the same toxic environment develop signs of the disease. In other species, it has been shown that the intestinal microbiota has an impact on digestion, metabolism, immune stimulation and protection from disease. The objective of this study was to characterize and compare fecal microbiota of horses suffering from AM and healthy co-grazers. Furthermore, potential d...
Page AE, Adam E, Arthur R, Barker V, Franklin F, Friedman R, Grande T, Hardy M, Howard B, Partridge E, Rutledge M, Scollay M, Stewart JC, Vale A....The ability to identify horses at risk for catastrophic injuries continues to be a pressing issue for the racing industry, especially given recent events in North America. Objective: Since most catastrophic injuries occur in areas of existing pathology and this pathology is likely to elicit an inflammatory response, it was hypothesised that analysis of messenger RNA (mRNA) expression would detect significant changes in select genes in horses at risk for a catastrophic injury. Methods: Prospective cohort study. Methods: Five racing jurisdictions across the United States participated in this stu...
Mondo E, Rinnovati R, Spadari A, Giacometti F, Serraino A, Savini F, Piva S.Respiratory diseases are the second most common cause of illnesses in horses, their etiology can be viral, bacterial, immune-mediated, or mechanical (Racklyeft and Love DN, Aust Vet J 78:549-59, 2000; Austin et al., J Am Vet Med Assoc 207:325-328, 1995; Arroyo et al., J Vet Intern Med 31:894-900, 2017). Klebsiella variicola is a Gram-negative bacterium that was initially identified as an endophyte in soil and plants such as bananas, rice, sugar cane and maize but recent studies have identified this microorganism as an emerging pathogen in humans (Rodríguez-Medina et al., Emerg Microbes Infec...
Nielsen JM, Fog P, Bojesen AM.The breeding prognosis for a mare with fungal (yeast or mold) endometritis is generally considered poor. To our knowledge, however, no reports have been published on the expected pregnancy rate for mares diagnosed with a fungal infection. Insemination records from 3,223 mares inseminated at two stud farms were retrospectively examined. Mares diagnosed with fungal endometritis were all treated with uterine lavage using physiological saline, intrauterine deposition of 100 mg Clotrimazole vagitorial tablets and oxytocin (10 i.e., i.m.) for three consecutive days. From mares with signs of endometr...
Egan S, Brama PAJ, Goulding C, McKeown D, Kearney CM, McGrath D.(1) Background: Postural sway is frequently used to quantify human postural control, balance, injury, and neurological deficits. However, there is considerably less research investigating the value of the metric in horses. Much of the existing equine postural sway research uses force or pressure plates to examine the centre of pressure, inferring change at the centre of mass (COM). This study looks at the inverse, using an inertial measurement unit (IMU) on the withers to investigate change at the COM, exploring the potential of postural sway evaluation in the applied domain. (2) Methods: The ...
Sanclemente JL, Rivera-Velez SM, Dasgupta N, Horohov DW, Wood PL, Sanz MG.Many foals that develop thoracic ultrasonographic lesions as a result of Rhodococcus equi infection heal on their own. However, most of these foals receive antimicrobials because foals at risk of developing clinical pneumonia cannot be identified. Untargeted lipidomics is useful to identify candidate biomarkers. Objective: (a) To describe the changes that occur in foal lipidomics as a result of ageing (birth to 8 weeks) and (b) To compare these results with those observed in foals after experimental infection with R. equi. Methods: Experimental study. Methods: Healthy newborn foals (n = 9) ...
Štritof Z, Mitchell C, Turk N, Habuš J, Hađina S, Perharić M, Waller AS.Clinical cases resembling strangles are regularly seen in some areas of Croatia. However, there are no data on the prevalence of infection and the clinical forms or geographic distribution of the disease. The aim of this study was to determine the seroprevalence of Streptococcus equi subspecies equi in horses resident in Croatia, in order to estimate the geographic distribution of infection. The study included 291 horse sera from the eight counties where the majority of Croatian horses are kept. Sera were tested by indirect ELISA (iELISA) for the presence of serum antibodies against S. equi pr...
Fedorka CE, Scoggin KE, El-Sheikh Ali H, Loux SC, Dini P, Troedsson MHT, Ball BA.Ascending placentitis is the leading cause of abortion in the horse. Interleukin (IL)-6 is considered predictive of placental infection in other species, but little is understood regarding its role in the pathophysiology of ascending placentitis. Sub-acute ascending placentitis was induced via trans-cervical inoculation of S zooepidemicus, and various fluids/serum/tissues collected 8 days later. Concentrations of IL-6 were detected within fetal fluids and serum in inoculated (n = 6) and control (n = 6) mares. RNASeq was performed on the placenta (endometrium and chorioallantois) to asses...
Favro G, Habib H, Gennity I, Puschner B, Hales EN, Finno CJ, Moeller BC.Equine neuroaxonal dystrophy/degenerative myeloencephalopathy (eNAD/EDM) is a hereditary, deteriorating central nervous disease in horses. Currently, the only way to confirm eNAD/EDM is through a postmortem histological evaluation of the central nervous system. Vitamin E, specifically the isoform alpha-tocopherol (α-TP), is known to protect eNAD/EDM susceptible horses from developing the clinical phenotype. While vitamin E is an essential nutrient in the diet of horses, there are no diagnostic tests able to quantitate vitamin E and its metabolites in urine. An ultra-performance liquid chromat...
Duquesne F, Breuil MF, Hans A, Petry S.The cultural diagnosis of the causal agent of contagious equine metritis (Taylorella equigenitalis) using transport swabs is challenging. Swabs must be placed in Amies charcoal medium, refrigerated during transport, and plated out at the laboratory no later than 48 h after sampling. In this study, the viability of T. equigenitalis strain CIP 79.7T in 11 commercial swab transport systems was initially compared at 1 day and 2 days of storage at ambient (20 ± 3 °C) or refrigerated (5 ± 3 °C) temperature. The four best swab transport systems, systems B, E, F (used as the reference) and K, were...
Dong J, Liu G, Gao N, Suo J, Matthijnssens J, Li S, Yuan D, Du Y, Zhang J, Yamashita N, Haga T, Cook FR, Zhu W.In contrast to horses, the only evidence suggesting gastrointestinal disease in neonatal donkeys is associated with Group A rotaviruses (RVAs) is the detection of viral antigens by ELISA in just 1 of 82 symptomatic donkey foals. No additional, more comprehensive investigations have been conducted, and RVAs if circulating in donkey populations have not been molecularly characterised. Objective: To investigate if RVAs are associated with an outbreak of severe enteritis in neonatal donkeys and if associated determine the genotype(s) along with the phylogenetic relationship to RVA strains circulat...
Nowacka-Woszuk J, Mackowski M, Stefaniuk-Szmukier M, Cieslak J.The equine graying with age causative mutation in the syntaxin-17 gene (STX17) has been known for over a decade, but proper genotyping of this variant remains challenging due to its molecular character (4.6-kb tandem duplication). Precise information on gray mutation status is important for horse breeders and veterinarians, since gray homozygous horses are more prone to developing aggressive melanoma tumors than heterozygotes. Since recent studies have confirmed that droplet digital PCR is a valuable technique for copy number analysis, we decided to investigate whether this method can be used ...
Story MR, Haussler KK, Nout-Lomas YS, Aboellail TA, Kawcak CE, Barrett MF, Frisbie DD, McIlwraith CW.Interest in the cervical spine as a cause of pain or dysfunction is increasingly becoming the focus of many equine practitioners. Many affected horses are presented for poor performance, while others will present with dramatic, sometimes dangerous behavior. Understanding and distinguishing the different types of neck pain is a starting point to comprehending how the clinical presentations can vary so greatly. There are many steps needed to systematically evaluate the various tissues of the cervical spine to determine which components are contributing to cervical pain and dysfunction. Osseous s...
Wilson AD, Heesom KJ, Mawby WJ, Mellor PS, Russell CL.IgE-mediated type 1 hypersensitivity reactions to the bites of insects are a common cause of skin disease in horses. Insect bite hypersensitivity (IBH) is most frequently associated with bites of Culicoides spp. and occurs in all parts of the world where horses and Culicoides coexist. The main allergens that cause IBH are probably some of the abundant proteins in the saliva of Culicoides associated with blood feeding. Western blots of Culicoides proteins separated by 1D gel-electrophoresis detected strong IgE responses in all horses with IBH to antigens in protein extracts from wild caught Cul...
Ziegler A, Hamza E, Jonsdottir S, Rhyner C, Wagner B, Schüpbach G, Svansson V, Torsteinsdottir S, Marti E.Insect bite hypersensitivity (IBH) is an allergic dermatitis of horses caused by bites of Culicoides spp. IBH does not occur in Iceland because of the absence of Culicoides, but the prevalence is high in horses imported from Iceland to environments where Culicoides are present. Objective: Test, in a longitudinal study before and after Culicoides exposure, whether a primary sensitizing Culicoides allergen can be identified and if an increase of allergen-specific immunoglobulin (Ig)E or IgG subclasses precedes clinical signs of IBH. Methods: Thirty two horses imported from Iceland to Europe; 16 ...
Morgan RA, Keen JA, Walker BR, Hadoke PW.Endocrinopathic laminitis (EL) is a vascular condition of the equine hoof resulting in severe lameness with both welfare and economic implications. EL occurs in association with equine metabolic syndrome and equine Cushing's disease. Vascular dysfunction, most commonly due to endothelial dysfunction, is associated with cardiovascular risk in people with metabolic syndrome and Cushing's syndrome. We tested the hypothesis that horses with EL have vascular, specifically endothelial, dysfunction. Healthy horses (n = 6) and horses with EL (n = 6) destined for euthanasia were recruited. We studied v...
Georges KC, Ezeokoli CD, Sparagano O, Pargass I, Campbell M, D'Abadie R, Yabsley MJ.Equine piroplasmosis due to Theileria equi and Babesia caballi is endemic in Trinidad. A case of equine piroplasmosis due to T. equi was diagnosed in a thoroughbred foal at 10h post-partum. A high parasitaemia (63%) of piroplasms was observed in a Wright-Giemsa(®) stained thin blood smear from the foal. In addition, the 18S rRNA gene for Babesia/Theileria was amplified from DNA extracted from the blood of the foal and the mare. Amplified products were subjected to a reverse line blot hybridization assay (RLB), which confirmed the presence of T. equi DNA in the foal. The mare was negative by R...
Newton JR, Wood JL, Chanter N.A matched case control study was used to determine infections and other factors associated with clinically apparent respiratory disease in young racehorses in training in the UK. A total of 170 cases, defined as horses with sudden onset coughing, nasal discharge or pyrexia, were identified and matched to 632 non-affected controls by trainer and time period. Factors examined included age, sex, time since entry into the training yard, time since last race and different infections including tracheal and nasopharyngeal (NP) bacteria and viruses. Multivariable conditional logistic regression (CLR) ...
Drolet BS, Reeves WK, Bennett KE, Pauszek SJ, Bertram MR, Rodriguez LL.In 2006, vesicular stomatitis New Jersey virus (VSNJV) caused outbreaks in Wyoming (WY) horses and cattle after overwintering in 2004 and 2005. Within two weeks of the outbreak onset, 12,203 biting flies and 194 grasshoppers were collected near three equine-positive premises in Natrona County, WY. Insects were identified to the species level and tested by RT-qPCR for VSNJV polymerase (L) and phosphoprotein (P) gene RNA. Collected dipterans known to be competent for VSV transmission included Simulium black flies and Culicoides biting midges. VSNJV L and P RNA was detected in two pools of female...
Mansour TA, Scott EY, Finno CJ, Bellone RR, Mienaltowski MJ, Penedo MC, Ross PJ, Valberg SJ, Murray JD, Brown CT.Transcriptome interpretation relies on a good-quality reference transcriptome for accurate quantification of gene expression as well as functional analysis of genetic variants. The current annotation of the horse genome lacks the specificity and sensitivity necessary to assess gene expression especially at the isoform level, and suffers from insufficient annotation of untranslated regions (UTR) usage. We built an annotation pipeline for horse and used it to integrate 1.9 billion reads from multiple RNA-seq data sets into a new refined transcriptome. This equine transcriptome integrates eight d...
McFarlane D, Paradis MR, Zimmel D, Sykes B, Brorsen BW, Sanchez A, Vainio K.Plasma α-melanocyte-stimulating hormone (α-MSH) and adrenocorticotropin (ACTH) concentrations in horses vary with season, confounding diagnostic testing for pituitary pars intermedia dysfunction (PPID). Objective: The goals of this study were to determine whether seasonal variation in plasma α-MSH and ACTH concentrations in horses is influenced by geographic location, breed, or PPID. Methods: Healthy light breed horses residing in Florida, Massachusetts, and Finland (n = 12 per group); healthy Morgan horses (n = 13); healthy ponies (n = 9) and horses with PPID (n = 8). Methods: Monthly plas...
Moore BD, Balasuriya UB, Hedges JF, MacLachlan NJ.Equine viral arteritis (EVA) is an endotheliotropic viral disease of horses caused by equine arteritis virus (EAV). Although there is only one serotype of EAV, there is marked variation in the virulence of different strains of the virus. The replication and cytopathogenicity of three well-characterized strains of EAV of different virulence to horses were compared in rabbit kidney (RK-13) and primary equine pulmonary artery endothelial cells (ECs). Viral protein expression, plaque size, and cytopathogenicity of all three viruses were similar in RK-13 cells, whereas two virulent strains of EAV w...
Lohmann KL, Vandenplas ML, Barton MH, Bryant CE, Moore JN.Lipopolysaccharide (LPS) antagonists inhibit the response of inflammatory cells to LPS, presumably by competitive inhibition, and may be of therapeutic value in the treatment of endotoxemia and sepsis. The inhibitory effects of some LPS antagonists are restricted to certain host species, however, as the same molecules can have significant endotoxic activity in other species. This species-specific recognition appears to be mediated by Toll-like receptor 4 (TLR4) and/or MD-2. We have shown previously that LPS from Rhodobacter sphaeroides ( RsLPS) is an LPS antagonist in human cells but an agonis...
AIDS reviewsNovember 6, 2003
Volume 5, Issue 3 156-164
Towers GJ, Goff SP.Pathogenic retroviruses have driven the evolution of several dominant-acting mechanisms able to block infection and protect the host. These are exemplified by the mouse gene Fv1, which encodes a Gag-like protein able to protect against murine leukemia virus (MLV) infection. The block is saturable, occurs after reverse transcription and is directed against the viral capsid gene. Several other mammalian species are also able to block MLV infection with the same capsid specificity. A human gene with this activity has been named Ref1. Recently, primates have been shown to restrict a variety of ret...
Fagerness AJ, Flaherty MT, Perry ST, Jia B, Payne SL, Fuller FJ.Equine infectious anemia virus (EIAV) is a macrophage-tropic lentivirus that persistently infects horses and causes a disease that is characterized by periodic episodes of fever, thrombocytopenia, and viremia. EIAV encodes only four regulatory/accessory genes, (tat, rev, ttm, and S2) and is the least genetically complex of all known lentiviruses. We sought to determine the role of the EIAV S2 accessory gene of EIAV by introducing mutations that would prevent S2 expression on the p19/wenv17 infectious molecular clone. Virus derived from the p19/wenv17 molecular clone is highly virulent and rout...
Balasuriya UBR, Hedges JF, Smalley VL, Navarrette A, McCollum WH, Timoney PJ, Snijder EJ, MacLachlan NJ.Equine arteritis virus (EAV) causes a persistent infection of the reproductive tract of carrier stallions. The authors determined the complete genome sequences of viruses (CW96 and CW01) that were present 5 years apart in the semen of a carrier stallion (CW). The CW96 and CW01 viruses respectively had only 85.6 % and 85.7 % nucleotide identity to the published sequence of EAV (EAV030). The CW96 and CW01 viruses had two 1 nt insertions and a single 1 nt deletion in the leader sequence, and a 3 nt coding insertion in ORF1a; thus their genomes included 12 708 nt as compared to the 12 704 nt in EA...
Ma H, Lundy JD, Cottle EL, O'Malley KJ, Trichel AM, Klimstra WB, Hartman AL, Reed DS, Teichert T.Alphaviruses such as Venezuelan equine encephalitis virus (VEEV) and Eastern equine encephalitis virus (EEEV) are arboviruses that can cause severe zoonotic disease in humans. Both VEEV and EEEV are highly infectious when aerosolized and can be used as biological weapons. Vaccines and therapeutics are urgently needed, but efficacy determination requires animal models. The cynomolgus macaque (Macaca fascicularis) provides a relevant model of human disease, but questions remain whether vaccines or therapeutics can mitigate CNS infection or disease in this model. The documentation of alphavirus e...
Kuroda T, Kinoshita Y, Niwa H, Shinzaki Y, Tamura N, Hobo S, Kuwano A.Meticillin-resistant Staphylococcus aureus (MRSA) infections have been confirmed in hospitalised Thoroughbred racehorses at the hospitals of two training centres in Japan since 2009. To investigate the source of infection, the authors examined the rate of nasal MRSA colonisation in 600 healthy Thoroughbred racehorses, 53 veterinarians and 16 office staff at the racehorse hospitals of the two training centres. MRSA was not isolated from healthy Thoroughbred racehorses or hospital office staff. However, MRSA was isolated from 16 veterinarians (30.1 per cent), and the colonisation rate was signif...
Del Piero F, Wilkins PA, Dubovi EJ, Biolatti B, Cantile C.Natural eastern equine encephalitis alphavirus (EEEV) infection was diagnosed in two adult horses with anorexia and colic, changes in sensorium, hyperexcitability, and terminal severe depression. Myocardium, tunica muscularis of stomach, intestine, urinary bladder, and spleen capsule had coagulative necrosis and perivascular lymphocytic infiltrate. Central nervous system (CNS) lesions were diffuse polioencephalomyelitis with leptomeningitis characterized by perivascular T lymphocyte cuffing, marked gliosis, neuronophagia, and multifocal microabscesses. Lesions were more prominent within cerebr...
Lane JG, Mair TS.The clinical records of 100 cases of headshaking in horses were reviewed. Possible causes of the abnormal behaviour were identified in 11 animals; these included ear mite infestation, otitis interna, cranial nerve dysfunction, cervical injury, ocular disease, guttural pouch mycosis, dental periapical osteitis and suspected vasomotor rhinitis. However, in only two of these could it be shown that correction of the abnormality led to elimination of the headshaking. The additional clinical signs exhibited by the other idiopathic cases of headshaking included evidence of nasal irritation, sneezing ...
DeRouen A, Spriet M, Aleman M.The sixth cervical vertebra (C6) has unique morphology due to a ventral extension from the transverse process known as the ventral lamina. Little information was found regarding the prevalence and clinical relevance of morphologic variations. Aims of this observational, retrospective study were to characterize C6 morphologic variations in a large sample of horses. Cervical radiographic studies of 100 horses were retrieved. Data recorded were signalment, clinical history, morphology of the C6 ventral lamina, presence of articular process osteoarthritis, and presence of static vertebral canal st...
Wagner B, Glaser A, Hillegas JM, Erb H, Gold C, Freer H.West Nile virus (WNV) is a zoonotic pathogen of global importance. In horses with neurological signs, detection of WNV-specific immunoglobulin M (IgM) in serum is widely used to identify clinical cases of WNV encephalitis. Here, we describe the development of two monoclonal antibodies (mAbs) to equine IgM which were used in a WNV IgM-specific enzyme-linked immunosorbent assay (ELISA). Their performance was compared to an established assay based on polyclonal anti-IgM. Check test serum samples from the National Veterinary Service Laboratory (NVSL) were used to evaluate the performance of the th...
Merkens HW, Schamhardt HC.Force plate data from walking horses were used to evaluate the locomotion of a group of six horses during experimentally induced lameness in a forelimb or a hindlimb. By tightening or loosening screws in modified horseshoes the resulting pressure pain on the sole enabled induction and release of three different degrees of supporting lameness within a period of 2 h. The ground reaction force (GRF) patterns of the different recording sessions were compared with control data of the same horse as well as with the 'standard' horse data using a quantitative evaluation procedure involving 93 GRF para...
Dixon PM, Tremaine WH, Pickles K, Kuhns L, Hawe C, McCann J, McGorum BC, Railton DI, Brammer S.Of 400 horses referred because of equine dental disease, 162 suffered from primary apical infections of their cheek teeth (CT), including 92 with maxillary CT infections and 70 with mandibular CT infections. Maxillary swellings and sinus tracts were more common (82 and 26% incidence, respectively) with infections of the rostral 3 maxillary CT, than with infections of the caudal 3 maxillary CT (39 and 5% incidence, respectively). Nasal discharge was more commonly present with caudal (95%) than rostral (23%) maxillary CT infections. Mandibular CT apical infections commonly had mandibular swellin...
Karakulska J, Fijałkowski K, Nawrotek P, Pobucewicz A, Poszumski F, Czernomysy-Furowicz D.The aim of this study was an analysis of the staphylococcal flora of the nasal cavity of 42 healthy horses from 4 farms, along with species identification of CoNS isolates and determination of resistance to 18 antimicrobial agents, particularly phenotypic and genotypic methicillin resistance. From the 81 swabs, 87 staphylococci were isolated. All isolates possessed the gap gene but the coa gene was not detected in any of these isolates. Using PCR-RFLP of the gap gene, 82.8% of CoNS were identified: S. equorum (14.9%), S. warneri (14.9%), S. sciuri (12.6%), S. vitulinus (12.6%), S. xylosus (11....
Reef VB, Vaala WE, Worth LT, Sertich PL, Spencer PA.Mares with complicated pregnancies (illness, problems at parturition or delivery of an abnormal foal, n = 30) were scanned transabdominally from 298 days gestation to term in order to measure fetal size, evaluate fetal well-being and characterise the intrauterine environment. The results of the last scan obtained prior to parturition were compared to normal data obtained from fetuses of comparable gestational age to develop a biophysical profile specific for the equine fetus. Twelve mares produced a normal foal (positive outcome) and 18 mares delivered 19 abnormal foals (negative outcome). Bot...
Johnson CB, Taylor PM.We have investigated in eight ponies the effects of three different end-tidal concentrations of halothane, isoflurane and methoxyflurane on median (F50) and 95% spectral edge (F95) frequencies of the EEG and the second differential (DD) of the middle latency auditory evoked potential (MLAEP). The three concentrations of each agent were chosen to represent approximately the minimum alveolar concentration (MAC), 1.25 MAC and 1.5 MAC for each agent. During halothane anaesthesia, F95 decreased progressively as halothane concentration increased, from mean 13.9 (SD 2.6) at 0.8% to 11.9 (1.1) at 1.2%...
Tóth F, Frank N, Martin-Jiménez T, Elliott SB, Geor RJ, Boston RC.Hyperinsulinaemia is detected in horses with insulin resistance (IR) and has previously been attributed to increased pancreatic insulin secretion. Connecting peptide (C-peptide) can be measured to assess pancreatic function because it is secreted in equimolar amounts with insulin and does not undergo hepatic clearance. Objective: A human double antibody radioimmunoassay (RIA) detects C-peptide in equine serum and concentrations would reflect responses to different stimuli and conditions. Methods: A validation procedure was performed to assess the RIA. Six mature mares were selected and somatos...
le Jeune SS, Nieto JE, Dechant JE, Snyder JR.Gastroscopic examinations were performed in 62 Thoroughbred broodmares (33 pregnant, 29 non-pregnant) at one breeding farm to investigate the prevalence of gastric ulceration. Age, pregnancy status, race earnings, last race start, herd size, medical history, number of live foals, breeding years, feed type and number of feedings were recorded, plus coat condition and body condition score were determined. Twenty-one mares were re-evaluated after foaling, and the foaling date, foal weight at birth and placenta weight were recorded. The overall prevalence of gastric ulcers was 70.9%, with a median...
Kajabi AW, Casula V, Sarin JK, Ketola JH, Nykänen O, Te Moller NCR, Mancini IAD, Visser J, Brommer H, René van Weeren P, Malda J, Töyräs J....Chondral lesions lead to degenerative changes in the surrounding cartilage tissue, increasing the risk of developing post-traumatic osteoarthritis (PTOA). This study aimed to investigate the feasibility of quantitative magnetic resonance imaging (qMRI) for evaluation of articular cartilage in PTOA. Articular explants containing surgically induced and repaired chondral lesions were obtained from the stifle joints of seven Shetland ponies (14 samples). Three age-matched nonoperated ponies served as controls (six samples). The samples were imaged at 9.4 T. The measured qMRI parameters included ...
Dembek KA, Onasch K, Hurcombe SD, MacGillivray KC, Slovis NM, Barr BS, Reed SM, Toribio RE.The renin-angiotensin-aldosterone system (RAAS) and hypothalamic-pituitary-adrenal axis (HPAA) and their interactions during illness and hypoperfusion are important to maintain organ function. HPAA dysfunction and relative adrenal insufficiency (RAI) are common in septic foals. Information is lacking on the RAAS and mineralocorticoid response in the context of RAI in newborn sick foals. Objective: To investigate the RAAS, as well as HPAA factors that interact with the RAAS, in hospitalized foals, and to determine their association with clinical findings. We hypothesized that critical illness i...
Loftus JP, Johnson PJ, Belknap JK, Pettigrew A, Black SJ.Inflammation and dysregulation of endogenous matrix metalloproteinase (MMP) production are implicated in the development of equine laminitis. In this study, we examine quantitative relationships among levels of leukocyte-derived proMMP-9 and MMP-9, lamellar proMMP-2 and MMP-2, and expression of proMMP-2 processing enzymes, MT1-MMP/PACE4, as steps towards determining whether inflammation and dysregulation of endogenous MMP production are independent or co-dependent processes. Methods: Archived samples of lamellae from horses with naturally acquired laminitis (n = 12), and from horses administer...
Theoret CL, Bolwell CF, Riley CB.To determine the frequency and type of skin wounds encountered by New Zealand veterinarians in their equine patients, the duration and estimated costs of treatment as well as the expected outcomes for these wounds. Methods: An online survey was sent to all veterinarians registered with the New Zealand Equine Veterinary Association. The survey comprised questions on the location and experience of respondents, the number of wound-related cases in relation to the total equine caseload, the type and anatomical location of wounds treated, the frequency, duration and costs of treatments, the outcome...
