Infectious diseases in horses encompass a range of illnesses caused by bacteria, viruses, fungi, or parasites. These diseases can affect various systems within the equine body, leading to symptoms that range from mild discomfort to severe systemic illness. Common infectious diseases in horses include equine influenza, strangles, equine herpesvirus, and West Nile virus. These diseases can be transmitted through direct contact with infected animals, contaminated surfaces, or vectors such as insects. Understanding the mechanisms of transmission, pathogenesis, and immune response is essential for effective prevention and control. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, diagnosis, treatment, and management of infectious diseases in horses.
Brosnahan MM, Damiani A, van de Walle G, Erb H, Perkins GA, Osterrieder N.Available vaccines fail to induce lasting and protective immunity to equine herpesvirus 1 (EHV-1) associated diseases. RNA interference is a novel approach showing promise for therapeutic use in outbreak situations. This study examined the effect of small interfering RNA (siRNA) on clinical signs as well as the presence of live virus and viral DNA in nasal secretions and peripheral blood mononuclear cells (PBMCs) in horses experimentally infected with EHV-1. siRNA targeting two EHV-1 genes (glycoprotein B and the origin binding protein) was administered 12h before and 12h after intranasal infe...
Dzieciatkowski T, Przybylski M, Cymerys J, Turowska A, Chmielewska A, Tucholska A, Banbura MW.Equine herpesvirus type 1 (EHV-1) is one of the major viral agents causing diseases in horses common worldwide. A variety of techniques, including PCR, have been used to diagnose EHV-1 infections. In this paper, an attempt of real-time PCR has been described, which uses specific fluorochrome-labeled TaqMan probes for detection of viral DNA. This method does not require post-amplification manipulations, thereby reducing the risk of cross-contamination. The assay was sensitive enough to detect EHV-1 sequences in different clinical samples, as well in mice neuronal cell cultures. The technique wa...
Jacobi S, Townsend WM, Bolin CA.To evaluate whether equine serum administered via a simulated subpalpebral lavage system (SPL) supports proliferation of Streptococcus zooepidemicus or Pseudomonas aeruginosa within the tubing. Methods: A sterile i.v. catheter with injection cap was inserted into sterilized silicone tubing (Mila). To mimic an SPL within the dorsal conjunctival fornix, the tubing was secured to an elevated platform. The tip of the tubing extended from the platform into a vial containing culture medium just inoculated with approximately 1.5 x 10(8) CFU/mL P. aeruginosa or S. zooepidemicus. To mimic administratio...
Arrigo NC, Adams AP, Weaver SC.The eastern equine encephalitis (EEE) complex consists of four distinct genetic lineages: one that circulates in North America (NA EEEV) and the Caribbean and three that circulate in Central and South America (SA EEEV). Differences in their geographic, pathogenic, and epidemiologic profiles prompted evaluation of their genetic diversity and evolutionary histories. The structural polyprotein open reading frames of all available SA EEEV and recent NA EEEV isolates were sequenced and used in evolutionary and phylogenetic analyses. The nucleotide substitution rate per year for SA EEEV (1.2 x 10(-4...
Wobeser BK, Godson DL, Rejmanek D, Dowling P.A protozoal parasite identified as Neospora hughesi was found in inflammatory lesions in the central nervous system of a Canadian-born adult horse presented with neurological signs. This is believed to be the first case of equine protozoal myeloencephalitis (EPM) caused by Neospora hughesi in a horse outside of the United States. Un parasite protozoaire identifié comme a été trouvé dans les lésions inflammatoires du système nerveux central d’un cheval adulte né au Canada présentant des signes neurologiques. On croit qu’il s’agit du premier cas d’encéphalomyélite protozoai...
Maurizi L, Marié JL, Aoun O, Courtin C, Gorsane S, Chal D, Davoust B.A precise assessment of the epidemiological extent of equine Lyme disease is not well established in metropolitan France, French Guiana, and Africa (Chad, Djibouti, Ivory Coast, Gabon, and Democratic Republic of Congo). Blood samples were obtained from 570 horses. The samples were tested for Borrelia burgdorferi infection by a commercial ELISA Dot-Blot method (SNAP 4 Dx; IDEXX S. Laboratory). Lyme disease antibodies were only detected in metropolitan France, specifically in the eastern and center-western regions (48% and 31%). The geographical distribution of the disease follows the distributi...
Bryant NA, Paillot R, Rash AS, Medcalf E, Montesso F, Ross J, Watson J, Jeggo M, Lewis NS, Newton JR, Elton DM.During 2007, large outbreaks of equine influenza (EI) caused by Florida sublineage Clade 1 viruses affected horse populations in Japan and Australia. The likely protection that would be provided by two modern vaccines commercially available in the European Union (an ISCOM-based and a canarypox-based vaccine) at the time of the outbreaks was determined. Vaccinated ponies were challenged with a representative outbreak isolate (A/eq/Sydney/2888-8/07) and levels of protection were compared.A group of ponies infected 18 months previously with a phylogenetically-related isolate from 2003 (A/eq/South...
Gryspeerdt AC, Vandekerckhove AP, Garré B, Barbé F, Van de Walle GR, Nauwynck HJ.Equine herpesvirus 1 (EHV1) replicates in the respiratory tract of horses, after which infected leukocytes transport virus throughout the body, resulting in abortion or nervous system disorders. Two EHV1 strains circulate in the field: neurovirulent and non-neurovirulent. To investigate differences in replication in the upper respiratory tract (URT), an experimental inoculation study in ponies was performed with both strains. Two groups of six ponies, were inoculated intranasally with 10(6.5) TCID(50) of either strain. Clinical signs, nasal shedding and viremia were evaluated. At early time po...
Gaede W, Reckling KF, Schliephake A, Missal D, Hotzel H, Sachse K.At a stud farm of Trakehner horses, all 33 foals of a birth cohort developed conjunctivitis and serous to muco-purulent rhinitis, and 7 older horses showed recurrent signs of conjunctivitis. Examination of nasal and conjunctival swabs by bacterial and cell culture, as well as real-time PCR, ArrayTube microarray analysis and DNA sequencing led to the identification of Chlamydophila (C.) caviae (first description in horses) and Streptococcus (S.) equi subsp. zooepidemicus. We presume a synergistic effect associated with these two agents by hypothesising that primary lesions were set by C. caviae...
Lu Z, Chambers TM, Boliar S, Branscum AJ, Sturgill TL, Timoney PJ, Reedy SE, Tudor LR, Dubovi EJ, Vickers ML, Sells S, Balasuriya UB.The objective of this study was to develop and evaluate new TaqMan real-time reverse transcription-PCR (rRT-PCR) assays by the use of the minor groove binding probe to detect a wide range of equine influenza virus (EIV) strains comprising both subtypes of the virus (H3N8 and H7N7). A total of eight rRT-PCR assays were developed, targeting the nucleoprotein (NP), matrix (M), and hemagglutinin (HA) genes of the two EIV subtypes. None of the eight assays cross-reacted with any of the other known equine respiratory viruses. Three rRT-PCR assays (EqFlu NP, M, and HA3) which can detect strains of th...
Craigo JK, Barnes S, Zhang B, Cook SJ, Howe L, Issel CJ, Montelaro RC.Equine infectious anemia virus (EIAV), a lentivirus that infects horses, has been utilized as an animal model for the study of HIV. Furthermore, the disease associated with the equine lentivirus poses a significant challenge to veterinary medicine around the world. As with all lentiviruses, EIAV has been shown to have a high propensity for genomic sequence and antigenic variation, especially in its envelope (Env) proteins. Recent studies have demonstrated Env variation to be a major determinant of vaccine efficacy, emphasizing the importance of defining natural variation among field isolates o...
Boyle AG, Sweeney CR, Kristula M, Boston R, Smith G.To identify factors associated with an increased likelihood that horses would have a serum Streptococcus equi SeM-specific antibody titer > or = 1:1,600. Methods: Cross-sectional study. Methods: 188 healthy client-owned horses. Methods: A single serum sample from each horse was tested for SeM-specific antibody titer with an ELISA. Multivariate logistic regression was used to identify factors associated with having a titer > or = 1:1,600. Results: Age, breed, and vaccination status were significantly associated with the likelihood of having a titer > or = 1:1,600. The odds of having a ...
Retteg Pauls S, Jottini S, Takai S, Venner M, Wohlsein P.A 3-month-old female trotter foal was euthanized due to severe dyspnoea. Pathomorphologically a chronic granulomatous to necrotizing pneumonia was found and Rhodoccocus (R.) equi was isolated microbiologically. An immunohistological method using a murine monoclonal antibody against a 15-17 kDa antigen of virulent R. equi was established in formalin-fixed and paraffin-embedded tissue sections using various antigen retrieval techniques to optimize the staining results. Microwave treatment was most suitable for the demonstration of bacterial antigen localized predominantly in intralesional macrop...
Adaszek Ł, Winiarczyk S, Łukaszewska J.The study was aimed at determining the cause of a disease in a horse exhibiting symptoms of fever, joint effusion, weakness, and extravasations on the mucous membranes. Blood was drawn from the animal for haematological and biochemical molecular tests. The PCR technique revealed the presence of 16S RNA Ehrlichia spp. genetic material in the blood samples. DNA amplification by means of primers EHR 521 and EHR 747 gave a product with a volume of 247 bp.The sequence of the PCR product obtained showed a 97.6% similarity with a sequence of a fragment of 16S RNA Ehrlichia phagocytophila, gene number...
Bright LA, Burgess SC, Chowdhary B, Swiderski CE, McCarthy FM.The horse genome is sequenced, allowing equine researchers to use high-throughput functional genomics platforms such as microarrays; next-generation sequencing for gene expression and proteomics. However, for researchers to derive value from these functional genomics datasets, they must be able to model this data in biologically relevant ways; to do so requires that the equine genome be more fully annotated. There are two interrelated types of genomic annotation: structural and functional. Structural annotation is delineating and demarcating the genomic elements (such as genes, promoters, and ...
Ryu SH, Koo HC, Park YK, Kim JM, Jung WK, Davis WC, Park YH, Lee CW.Equine respiratory disease is a common cause of poor performance and training interruptions. The higher incidence rate of infectious upper respiratory disease (IURD) in thoroughbred racehorses at the Seoul Race Park coincided with the frequent stabling season, shorter stabling periods, and younger ages in this study. Incidence rates were also correlated with significantly lower proportions of cells expressing MHC class II-, CD2 antigen-, CD4+- or CD8+-T lymphocyte-, and B lymphocyte in IURD patients compared with healthy control groups in the summer and fall and in 2-and-3-year-old groups. The...
Tamarit A, Gutierrez C, Arroyo R, Jimenez V, Zagalá G, Bosch I, Sirvent J, Alberola J, Alonso I, Caballero C.An outbreak of Trypanosoma evansi infection that occurred in mainland Spain is described. The outbreak occurred on an equine and camel farm to which dromedary camels from an infected area of the Canary Islands had recently been introduced. One of these camels developed clinical signs and T. evansi was discovered in a blood smear examination. The herd was evaluated in order to determine the extent of the disease. The results showed that 76% of the camels, 35% of the donkeys and 2% of the horses were affected. The animals were isolated and treated using Cymelarsan((R)) (0.5mg/kg). After treatmen...
Guimarães-Ladeira CV, Palhares MS, Oliveira JS, Ramirez MA, Guedes RM.Proliferative enteropathy, caused by the intracellular bacterium Lawsonia intracellularis, has been described in horses in Australia, the USA, Canada and European countries but has not been reported in Latin America. The prevalence of the disease in horses worldwide is unknown. Objective: To evaluate the presence of subclinical L. intracellularis infection in horses in the state of Minas Gerais, Brazil. Methods: A longitudinal study using serology and PCR for detecting antibodies (IgG) and shedding of L. intracellularis in faecal samples, respectively, was conducted using a total of 223 horses...
Santín M, Vecino JA, Fayer R.This is the first report of Enterocytozoon bieneusi in an equid species. Feces from 195 horses from 4 locations in Colombia were examined for E. bieneusi by polymerase chain reaction. Of these, 21 horses (10.8%) were found positive for E. bieneusi . The prevalence of E. bieneusi in horses 1 yr of age (2.5%). No significant differences in prevalence were observed between male (13.7%) and female horses (9%). Sequencing of the internal transcribed spacer region of the SSUrRNA locus identified 3 genotypes. Two genotypes appear to be unique to horses and were named Horse 1 and Horse 2. A third geno...
Sergeant ES, Kirkland PD, Cowled BD.During the Australian epidemic of equine influenza in 2007, tens of thousands of horses were infected. From the resulting field data, 475 known infected and 1323 uninfected horses were identified to allow a post outbreak evaluation of the performance of the commonly used bELISA for influenza A under field conditions. A variety of techniques, such as ROC plots, area under the curve and hypothesis testing were used to assess the overall performance of the test. The test was deemed to be accurate (area under curve=0.993+/-0.003 standard error) and significantly informative (z=-32.0; p or =50) wer...
Konishi E.The literature on natural infections with Japanese encephalitis virus in Japan and subclinical:clinical infection rates was summarized. To detect natural infections, conventional serologic methods were used in the past, while nonstructural 1 protein-based methods have been used recently. Annual infection rates in humans and horses indicated the status of natural virus activity in Japan.
Gao X, Jiang CG, Han XE, Zhao LP, Shen RX, Xiang WH, Zhou JH.To elucidate the function of the S2 gene in equine infectious anemia virus (EIAV) and its role in the attenuation of the Chinese attenuated EIAV vaccine strains, the S2 in the EIAV vaccine strain EIAV (FDDV) was reverse-mutated and the in vitro replication character of the resultant virus was evaluated. Based on the sequence variation of the S2 gene between the EIAV virulent strains and vaccine strains, all the four vaccine-specific sites in the S2 of an EIAV(FDDV) infectious clone, pFDDV3-8, were reverse-mutated to the sequences of the virulent strain EIAV(DV115). The reverse-mutated molecula...
Guss B, Flock M, Frykberg L, Waller AS, Robinson C, Smith KC, Flock JI.Streptococcus equi subspecies equi (S. equi) is a clonal, equine host-adapted pathogen of global importance that causes a suppurative lymphodendopathy of the head and neck, more commonly known as Strangles. The disease is highly prevalent, can be severe and is highly contagious. Antibiotic treatment is usually ineffective. Live attenuated vaccine strains of S. equi have shown adverse reactions and they suffer from a short duration of immunity. Thus, a safe and effective vaccine against S. equi is highly desirable. The bacterium shows only limited genetic diversity and an effective vaccine coul...
Attoui H, Mendez-Lopez MR, Rao S, Hurtado-Alendes A, Lizaraso-Caparo F, Mohd Jaafar F, Samuel AR, Belhouchet M, Pritchard LI, Melville L, Weir RP....During 1997, two new viruses were isolated from outbreaks of disease that occurred in horses, donkeys, cattle and sheep in Peru. Genome characterization showed that the virus isolated from horses (with neurological disorders, 78% fatality) belongs to a new species the Peruvian horse sickness virus (PHSV), within the genus Orbivirus, family Reoviridae. This represents the first isolation of PHSV, which was subsequently also isolated during 1999, from diseased horses in the Northern Territory of Australia (Elsey virus, ELSV). Serological and molecular studies showed that PHSV and ELSV are very s...
Pusterla N, Byrne BA, Hodzic E, Mapes S, Jang SS, Magdesian KG.A quantitative real-time (RT)-PCR assay was developed to detect Salmonella spp. in the feces of 911 equine species admitted to a veterinary hospital. Fresh feces and feces enriched for 24h in selenite broth were assessed by conventional culture and by RT-PCR targeting the Salmonella invA gene. The detection limit for the RT-PCR assay was 3 and 10 organisms, respectively, when spiked samples were purified from selenite broth and feces. The analytical specificity was 100% based on the detection of a panel of 40 salmonella serotypes from five serogroups and the lack of cross-reactivity with non-r...
Fortier G, van Erck E, Pronost S, Lekeux P, Thiry E.Equine gammaherpesviruses (γEHV) have been widely studied over the past 45 years and many isolates have been characterised. Despite this, the diagnosis of γEHV infection remains difficult to establish as its clinical manifestations lack specificity, ranging from mild respiratory signs in a small number of animals to outbreaks in large groups of young horses. This review focuses on the epidemiology, pathogenesis, clinical manifestations and diagnosis of equine herpesvirus (EHV)-2 and -5 infections, as well as on the genetic variation of these viruses. Study of these variations has resulted in...
Barros IN, Silva SO, Nogueira Neto FS, Asano KM, Souza SP, Richtzenhain LJ, Brandao PE.Gastroenteritis is one of the leading causes of morbidity and mortality among young and newborn animals and is often caused by multiple intestinal infections, with rotavirus and bovine coronavirus (BCoV) being the main viral causes in cattle. Given that BCoV is better studied than equine coronaviruses and given the possibility of interspecies transmission of these viruses, this research was designed to compare the partial sequences of the spike glycoprotein (S), hemagglutinin-esterase protein (HE), and nucleoprotein (N) genes from coronaviruses from adult cattle with winter dysentery, calves w...
Martínez-Torrecuadrada JL, Díaz-Laviada M, Roy P, Sánchez C, Vela C, Sánchez-Vizcaíno JM, Casal JI.Fifteen horses were experimentally infected with African horse sickness virus (AHSV) serotype 4. To learn more about the time course of production and specificity of AHSV-specific antibodies, sera were analyzed by immunoblot analysis. Only animals that survived for more than 9 days were able to develop a humoral immune response detectable by immunoblotting. The earliest serological markers corresponded mainly to VP5, VP6, and NS2 and to a lesser extent to VP3, NS1, and NS3. Neutralizing antibodies to VP2 were not detected by immunoblotting, suggesting that they are mostly conformation dependen...
Miszczak F, Shuck KM, Lu Z, Go YY, Zhang J, Sells S, Vabret A, Pronost S, Fortier G, Timoney PJ, Balasuriya UB.This study showed that under specifically defined conditions with respect to nucleic acid extraction method and testing reagents, a previously described real-time reverse transcription-PCR (rRT-PCR) assay (T1 assay) provides sensitivity equal to or higher than that of virus isolation for the detection of equine arteritis virus in semen.
BMC research notesSeptember 24, 2015
Volume 8 471 doi: 10.1186/s13104-015-1441-0
Boukharta M, Azlmat S, Elharrak M, Ennaji MM.Three equine influenza viruses, A/equine/Nador/1/1997(H3N8), A/equine/Essaouira/2/2004(H3N8), and A/equine/Essaouira/3/2004(H3N8), were isolated from different Equidae during local respiratory disease outbreaks in Morocco in 1997 and 2004. Their non-structural (NS) genes were amplified and sequenced. Results: The results show high homology of NS nucleotide sequences of A/equine/Nador/1/1997 with European strains (i.e., A/equine/newmarket/2/93 and A/equine/Grobois/1/1998) and clustered into the European lineage. However, NS gene of A/equine/Essaouira/2/2004(H3N8) and A/equine/Essaouira/3/2004(H...
Lyons ET, Tolliver SC, Drudge JH, Granstrom DE, Collins SS.During the period 28 February-1 July 1992, fecal samples were collected and examined for eggs of Strongyloides westeri once from each of 382 horse foals (364 Thoroughbreds, 16 Standardbreds, one Lippizaner, and one draft-type horse) in central Kentucky. Ages of the foals at the time of sampling ranged from 7 to 63 days (mean 22 days). The nine farms in the study were considered to have overall excellent deworming programs. None of the foals had been treated with an antiparasitic compound before the study. Eggs of S. westeri were found in 6% (22 of 382) of the foals on 78% (7 of 9) of the farms...
Pusterla N, Leutenegger CM, Barnum SM, Byrne BA.In recent years, molecular approaches have been able to characterise the viability of equine upper respiratory tract pathogens using absolute molecular quantitation as well as detection of transcripts for virulence genes. Objective: The objective of this study was to investigate molecular surrogates for S. equi subspecies equi (S. equi) viability in biological samples from horses with strangles. Methods: Retrospective cross-sectional study. Methods: S. equi culture-positive and culture-negative upper airway secretions were assessed by qPCR at the genomic (gDNA) and complimentary DNA (cDNA) ...
Szeredi L, Pospischil A, Dencsö L, Mathis A, Dobos-Kovács M.A Lippizan mare aborted a male fetus a few days before the expected foaling date without showing any clinical sings. Focal lympho-histiocytic hepatitis in the foal and multiplex focal lympho-histiocytic villitis accompanied by villus necroses and marked hypertrophy of chorionic epithelial cells in the arcades were observed. Elongated nucleated organisms were seen in groups in vacuoles or solitarily located in the cytoplasm of the chorionic epithelial cells. The organisms were in large numbers and often extracellularly in areas of villitis and villus necroses. They were Gram-positive, stained w...
Kahn SK, Cohen ND, Bordin AI, Coleman MC, Heird JC, Welsh TH.The bacterium Rhodococcus equi causes pneumonia in foals that is prevalent at breeding farms worldwide. In the absence of an effective vaccine, transfusion of commercial plasma from donor horses hyperimmunised against R. equi is used by many farms to reduce the incidence of pneumonia among foals at farms where the disease is endemic. The effectiveness of hyperimmune plasma for controlling R. equi pneumonia in foals has varied considerably among reports. The purposes of this narrative review are: (1) to review early studies that provided a foundational basis for the practice of transfusion of h...
Trumpp KM, Parsley AL, Lewis MJ, Camp JW, Taylor SD.Tick paralysis has not been reported in horses in North America. Results: Two American Miniature horses were examined for progressive weakness and recumbency. Numerous ticks (Dermacentor variabilis) were found on both horses. Horse 1 was recumbent (grade 5/5 gait deficit) on presentation, whereas Horse 2 was standing but ataxic (grade 4/5 gait deficit) and tetraparetic. Both horses had decreased tongue and tail muscle tone, and had normal spinal reflexes. Cerebrospinal fluid cytology was normal. Equine herpesvirus-1 testing was negative. Unassigned: Ticks were removed within 24 hours of pres...
El-Hage CM, McCluskey MJ, Azuolas JK.Ross River Virus (RRV) was believed to be the cause of acute illness in four horses around the Bellarine peninsula in south-west Victoria, Australia. The horses presented with clinical signs including petechial haemorrhages, lymphadenopathy, distal limb swelling and reluctance to move. Fibrinogen was also elevated in three of the four horses. Whilst no virus was isolated, serological testing revealed elevated RRV IgM titres in all horses indicating acute infection. The outbreak occurred at a time when a known RRV vector, the mosquito Aedes camptorhynchus was recorded at very high levels in the...
Dietzel J, Kuhrt H, Stahl T, Kacza J, Seeger J, Weber M, Uhlig A, Reichenbach A, Grosche A, Pannicke T.Borna disease (BD) is a fatal disorder of horses, often characterized by blindness. Although degeneration of retinal neurons has been demonstrated in a rat model, there are controversial data concerning whether a similar degeneration occurs in the retina of infected horses. To investigate whether BD may cause degeneration of photoreceptors and possibly of other neuronal cells at least at later stages of the disease, we performed a detailed quantitative morphologic study of retinal tissue from Borna-diseased horses. BD was diagnosed by detection of pathognomonic Joest-Degen inclusion bodies in ...
Russi RC, Garcia L, Cámara MS, Soutullo AR.Equine infectious anaemia (EIA) is controlled by the identification of seropositive animals. The official diagnostic method is the agar gel immunodiffusion (AGID) test, which detects antibodies against a viral core protein (p26). Although AGID is inexpensive and specific, the report of results takes considerable time and the test has low analytical sensitivity. Objective: To validate our in-house indirect ELISA , following the World Organization of Animal Health (OIE) criteria. Methods: Test validation. Methods: Synthetic peptides gp90 and gp45 were used as antigens in ELISA . Tests used for v...
Dos Santos TM, Roier ECR, Pires MS, Santos HA, Vilela JAR, Peckle M, Paulino PG, Baldani CD, Massard CL.The present study aims to determine the frequencies of Theileria equi and Anaplasma phagocytophilum antibodies among horses from the state of Rio de Janeiro, Brazil, and to detect the presence of DNA of these pathogens through molecular methods. A total of 98 serum samples of horses from the municipality of Seropedica were tested by indirect immunofluorescence antibody (IFA) to detect anti-A. phagocytophilum and anti-T. equi IgG antibodies. In addition, quantitative real-time PCR (qPCR) was used to detect these pathogens in the DNA extracted from the whole blood and buffy coat of horses. Bivar...
McFarlane D.The aging process in people is associated with changes in adaptive and innate immune responses. Similar changes occur in aged horses. Age-related progressive impairment in the ability to respond to pathogen challenge and an increased inflammatory reactivity may predispose geriatric horses to many diseases of old age. Specific recommendations for immune modification of older horses, including an age-appropriate vaccination schedule, are not currently available. In addition, the effect of old age on risk of infectious disease is poorly documented. More work is needed to better understand the int...
Erol E, Shaffer CL, Lubbers BV.The alarming increase in rifampin and macrolide resistance among Rhodococcus equi isolates highlights the need to identify alternative therapeutic options that can effectively control rhodococcosis in foals while limiting the further development of drug resistance. Objective: To evaluate bacterial killing, antibiotic synergism and mutant prevention concentrations (MPCs) of clarithromycin alone and in combination with doxycycline, minocycline or rifampin against clinical isolates of R equi. Methods: In vitro experiments. Methods: Bacterial time-kill, fractional inhibitory concentration (checker...
Anlén KG.The effects on seven horses of bites by the European adder (Vipera berus) are described and compared with previously available information. The clinical signs varied from local swelling and mild systemic signs to severe systemic signs, including systemic inflammatory response, severe tissue necrosis, ventricular tachycardia and dysphagia. Two of the horses were treated with 'Zagreb' antiserum, and three that were not treated with antiserum were euthanased owing to complications related to the bites.
House JA.AHS is a noncontagious vector-borne disease of Equidae caused by Orbiviruses. Species susceptibility in decreasing order is horses, mules, donkeys, and zebras. The main vectors of AHS are culicoides. The disease is endemic in sub-Saharan Africa, but epizootics have occurred outside of this area on several occasions. The most recent outbreaks outside of the endemic area were in Spain, Morocco, and Portugal between 1987 and 1990. AHS causes mortality up to 95% and is classically divided into four clinical forms: the pulmonary, cardiac, mixed, and horse fever forms. Pathologic changes are subcuta...
Hill DE, Forbes L, Kramer M, Gajadhar A, Gamble HR.The horse is considered an aberrant host for the nematode parasite Trichinella spiralis, and many aspects of the biology and epidemiology of Trichinella infection in the horse are poorly understood. It has been reported that experimentally-infected horses produce a transient serological response to infection and that muscle larvae are cleared more rapidly than in parasite-adapted hosts such as the pig and humans. However, limited numbers of animals have been studied, and both the longevity of larvae in horse musculature and the immune response to Trichinella larvae remain unclear. In this stud...
Lindroth KM, Dicksved J, Pelve E, Båverud V, Müller CE.Free faecal liquid (FFL) is a condition in horses which manifests as differential defecation of solid and liquid phases of faeces. The etiology of FFL is currently unknown, but deviances in the hindgut microbiota has been suggested to be of importance. The present study aimed to compare the faecal bacterial composition of farm-matched horses with (case, n = 50) and without (control, n = 50) FFL. Samples were collected at three different occasions. The V3 and V4 regions of the 16S rRNA gene were amplified and sequenced using Illumina sequencing. Also, samples were cultivated for detecti...
White SD, Vandenabeele SI, Drazenovich NL, Foley JE.Malassezia-type yeasts previously have been observed on cytologic examination of the intermammary region of mares that presented with tail-head pruritus; topical antiyeast treatment resolved the pruritus. Further, Malassezia dermatitis has been observed in horses in intertriginous areas such as the udder and prepuce; the species of yeast was not confirmed. It is not known whether healthy mares or male horses can be carriers of this yeast in these body areas. Objective: Malassezia spp. are present in the intermammary region in healthy mares and the preputial fossa in healthy geldings. Methods: ...
Gutiérrez JM, Chaves F, Rojas E, Elizondo J, Avila C, Cerdas L.A monovalent antivenom was produced by immunizing two horses with venom of the pit viper Bothrops asper (Ophidia: Viperidae). Although development of the immune response against four toxic and enzymatic activities of the venom was similar in both horses during the first two thirds of the immunization schedule, antibody response in one of the horses reached much higher levels in the last part of the immunization. Immunoelectrophoretic analysis indicates that there were precipitating antibodies in the sera of these horses during all the stages of immunization. However, immunoprecipitation did no...
Bienert A, Bartmann CP, Verspohl J, Deegen E.In most cases the diagnosis of any molar dental disease in horses is made at an advanced stage, so that permanent restoration of the diseased teeth is not feasible. Complications such as bacteraemia and septicaemia due to infections as a result of dentogenous sinusitis and following dentosurgical procedures have been described in human medicine and in veterinary medicine. Twenty patients were available for examination from the Clinic for Horses of the School of Veterinary Medicine Hannover with molar dental disease in upper or lower jaw. As a result of this disease the infected tooth had to be...
Suganuma K, Acosta TJ, Valinotti MFR, Sanchez AR, Mossaad E, Elata A, Inoue N.Despite the epidemic situation of animal trypanosomosis caused by Trypanosoma evansi, Trypanosoma equiperdum and Trypanosoma vivax in South American countries, there are no reports for the prevalence of animal trypanosomes in Paraguay. In this study, 408 blood samples were obtained from apparently healthy horses from sixteen departments of Paraguay, for routine medical check-up from August to September 2019, and a polymerase chain reaction (PCR)-based cross-sectional study was carried out to identify trypanosome prevalence. The prevalence of Trypanozoon (T. evansi and T. equiperdum) and T. viv...
Kelen PV, Downs JA, Unnasch T, Stark L.A GIS-based risk index model was developed to quantify EEEV transmission risk to horses in the State of Florida. EEEV is a highly pathogenic arbovirus that is endemic along the east coast of the United States, and it is generally fatal to both horses and humans. The model evaluates EEEV transmission risk at individual raster cells in map on a continuous scale of 0 to 1. The risk index is derived based on local habitat features and the composition and configuration of surrounding land cover types associated with EEEV transmission. The model was verified and validated using the locations of docu...
Marshall K, Marsella R.Increased antimicrobial resistance highlights the need for alternatives to antibiotics. Bacteriophages, which are benign viruses that kill bacteria, are promising. We studied the efficacy of topical bacteriophages for treating equine staphylococcal superficial pyodermas. Eight isolates were tested against a bacteriophage bank, and a cocktail consisting of two bacteriophages was prepared. Twenty horses with clinical and cytological evidence of superficial pyoderma and confirmed infection based on swabbed culture were enrolled in the study. Each horse received both the bacteriophage cocktail a...
Kwasnik M, Gora IM, Rola J, Zmudzinski JF, Rozek W.The phylogenetic analysis of influenza virus is based mainly on the variable hemagglutinin or neuraminidase genes. However, some discrete evolutionary trends might be revealed when more conservative genes are considered. We compared all available in GenBank database full length NS sequences of equine influenza virus including Polish isolates. Four nucleotides at positions A202, A237, T672 and A714 and three amino acids at positions H59, K71 and S216 which are also present in A/eq/Pulawy/2006 and A/eq/Pulawy/2008 may be discriminating for the Florida sublineage. Threonine at position 83 seems t...
Wall GV, Wright IM, Barnardo C, Erasmus BJ, van Staden V, Potgieter AC.African horse sickness virus (AHSV) non-structural protein NS4 is a nucleocytoplasmic protein that is expressed in the heart, lung, and spleen of infected horses, binds dsDNA, and colocalizes with promyelocytic leukemia nuclear bodies (PML-NBs). The aim of this study was to investigate the role of AHSV NS4 in viral replication, virulence and the host immune response. Using a reverse genetics-derived virulent strain of AHSV-5 and NS4 deletion mutants, we showed that knockdown of NS4 expression has no impact in cell culture, but results in virus attenuation in infected horses. RNA sequencing (RN...
Lundström TS, Dahlén GG, Wattle OS.Swedish equine dental practices have empirically found that the prevalence of infundibular caries as a primary disorder in the first permanent premolar teeth (P2) of the horse upper jaw has increased during the last 10 years. A previously unknown bacterial species, Streptococcus devriesei (CCUG 47155T), which is related to Streptococcus mutans, has recently been isolated from these carious lesions. To understand the aetiology of caries in horses, it is essential to elucidate the relationship between S. devriesei and P2 infundibular caries. Methods: The anterior infundibulum of maxillary P2, or...
Bernardino P, James K, Barnum S, Corbin R, Wademan C, Pusterla N.Equine rhinitis B virus (ERBV) has been given little attention by practitioners compared to other respiratory viruses, mainly because of the lack of diagnostic modalities and association with clinical disease. The objective of the study was to determine the frequency of detection of ERBV in nasal secretions from 6568 horses with acute onset of respiratory signs. ERBV-positive qPCR results from nasal secretions submitted to a molecular diagnostic laboratory from 2013 to 2019 were reviewed. A total of 333 ERBV qPCR-positive samples (5.1%) were detected with increasing yearly frequency since the ...
Divers TJ, Tomlinson JE, Tennant BC.Theiler's disease (serum hepatitis) may occur in outbreaks or as single cases of acute hepatitis and is often associated with prior administration of equine-origin biologics approximately 4-10 weeks before the onset of clinical signs. Cases have also been described without any prior administration of blood products. The clinical disease has a low morbidity but high mortality and only adult horses are affected. The course of the disease is short, with horses either dying or completely recovering in a few days. Pathology in affected horses is predominantly centrilobular hepatocyte necrosis with ...
