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.
Padilla SL, Prieto K, Dohm DJ, Turell MJ, Klein TA, Fernández R, Watts DM, Lowen RG, Palacios GF, Pitt ML, Wiley MR, Nasar F.Venezuelan equine encephalitis virus (VEEV) is an important pathogen of medical and veterinary importance in the Americas. In this report, we present the complete genome sequences of five VEEV isolates obtained from pools of Culex (Melanoconion) gnomatos (4) or Culex (Melanoconion) pedroi (1) from Iquitos, Peru. Genetic and phylogenetic analyses showed that all five isolates grouped within the VEEV complex sister to VEEV IIIC and are members of subtype IIID. This is the first report of full-length genomic sequences of VEEV IIID.
Can FK, Tekin E, Sezen S, Clutter P.The aim of the present study was to evaluate the demographic characteristics, exposure features, and prophylactic care aspects of cases that presented to the emergency department of 1 state hospital in Turkey between 2013 and 2017 because of the risk of rabies contact. Methods: Data from the retrospective cohort study were obtained from ED records of Erzurum Palandöken State Hospital between August 2013 and June 2017 regarding patients presenting to emergency service after the risk of rabies contact. Evaluation forms included demographic characteristics of the patients, contact type, contacte...
Torpiano P, Nestorova N, Vella C.Streptococcus equi subsp. equi is a group C β-hemolytic streptococcus, and is an invasive pathogen with a very restricted host, causing the equine infection known as 'strangles'. It is a poor colonizer in horses, preferentially causing invasion and infection, compared with its ancestor Streptococcus equi subsp. zooepidemicus, which is considered an opportunistic commensal of the equine upper respiratory tract. In humans, S. equi subsp. equi causes invasive infections in immunocompromised hosts, often following close contact with horses. Such infections are associated with a high mortality, as...
Bambra W, Daly JM, Kendall NR, Gardner DS, Brennan M, Kydd JH.Equine influenza virus is a highly contagious respiratory pathogen that causes pyrexia, anorexia, lethargy and coughing in immunologically naïve horses. Vaccines against equine influenza are available and vaccination is mandatory for horses that participate in affiliated competitions, but this group forms a small proportion of the total horse population. The aims of this study were to: i) identify the equine influenza vaccination rate as reported in 2016 by horse owners in the United Kingdom (UK); ii) examine the demographics of owners and horses which were associated with significantly lower...
Tartor YH, El-Naenaeey EY, Gharieb NM, Ali WS, Ammar AM.Strangles displays a major challenge to veterinary medicine worldwide. However, no data on Streptococcus equi subsp. equi (S. equi) M protein alleles have been reported so far from Arabian horses. We report here for the first time the S. equi SeM alleles causing strangles in Arabian horses, and the associated risk factors for the disease. Duplicate samples from one hundred Arabian horses with acute strangles in confirmed outbreaks and sporadic cases were analysed by phenotypic methods and multiplex polymerase chain reaction (PCR) targeting streptokinase precursor, seeI and sodA genes. PCR and ...
Onen EA.The aim of this study was to evaluate formalin-inactivated autovaccination to treat cutaneous papillomatosis and to perform molecular typing of the papillomavirus in four horses (two foals, one 3-year-old filly and a 5-year-old stallion). Methods: Histopathological slides of lesions were prepared and stained with haematoxylin and eosin (H&E) to establish a diagnosis that was based on observation koilocytosis, which is a pathognomonic cytopathic change that is associated with papillomatosis, using light microscopy. Polymerase chain reaction (PCR) and DNA sequencing were performed using the ...
Tamura N, Okano A, Kuroda T, Niwa H, Kusano K, Matsuda Y, Fukuda K, Mita H, Nagata S.To clarify the detailed pharmacokinetics (PK) of orally administered voriconazole in tear fluid (TF) of horses for evaluating the efficacy of voriconazole secreted into TF against equine keratomycosis. Methods: Five healthy Thoroughbred horses. Methods: Voriconazole was administrated through a nasogastric tube to each horse at a single dose of 4.0 mg/kg. TF and blood samples were collected before and periodically throughout the 24 hours after administration. Voriconazole concentrations in plasma and TF samples were analyzed using liquid chromatography-electrospray tandem-mass spectrometry. T...
Léon A, Castagnet S, Maillard K, Paillot R, Giard JC.The present study described the evolution of antimicrobial resistance in equine pathogens isolated from 2016 to 2019. A collection of 7806 bacterial isolates were analysed for their in vitro antimicrobial susceptibility using the disk diffusion method. The most frequently isolated pathogens were group C Streptococci (27.0%), Escherichia coli (18.0%), Staphylococcus aureus (6.2%), Pseudomonas aeruginosa (3.4%), Klebsiella pneumoniae (2.3%) and Enterobacter spp. (2.1%). The majority of these pathogens were isolated from the genital tract (45.1%, n = 3522). With the implementation of two French n...
Huber L, Giguère S, Slovis NM, Álvarez-Narváez S, Hart KA, Greiter M, Morris ERA, Cohen ND.The use of mass antimicrobial treatment has been linked to the emergence of antimicrobial resistance in human and animal pathogens. Using whole-genome single-molecule real-time (SMRT) sequencing, we characterized genomic variability of multidrug-resistant Rhodococcus equi isolated from soil samples from 100 farms endemic for R. equi infections in Kentucky. We discovered the novel erm(51)-encoding resistance to MLS in R. equi isolates from soil of horse-breeding farms. Erm(51) is inserted in a transposon (TnErm51) that is associated with a putative conjugative plasmid (pRErm51), a mobilizable p...
Ramos CP, Lopes EO, Oliveira Júnior CA, Diniz AN, Lobato FCF, Silva ROS.Considering the lack of studies evaluating the performance of commercially available methods for diagnosis of Clostridioides (Clostridium) difficile infection (CDI) in animals, the present study aimed to assess an immunochromatographic test for detection of glutamate dehydrogenase (GDH) and A/B toxins of C. difficile, also evaluated by an ELISA kit, in foals and neonatal piglets. Intestinal contents of 47 piglets and feces of 35 foals were tested to GDH antigen and A/B toxins in a lateral flow method (Ecodiagnostica, Brazil). Also, these samples were submitted to A/B toxin detection by an ELIS...
Song R, Ma Y, Hu Z, Li Y, Li M, Wu L, Li C, Dao E, Fan X, Hao Y, Bayin C.Dermacentor marginatus Sulkzer is a common tick species found in the Xinjiang Uygur Autonomous Region (XUAR) of China, and is a vector for a variety of pathogens. To determine the potential distribution of this tick species in Xinjiang, a metadata containing 84 D. marginatus presence records combined with four localities from field collection were used for MaxEnt modeling to predict potential distribution of this tick species. Identification of tick samples showed 756 of 988 (76%) were D. marginatus. MaxEnt modeling results indicated that the potential distribution of this tick species was mai...
Salco R, Bowers J, Hernandez V, Barnum S, Pusterla N.This study aimed to determine if the administration of a modified live equine influenza virus vaccine (FluAvert) to foals would positively impact their health and reduce colonization of their upper airways with equine herpesviruses (EHV) during the weaning period. A single dose of FluAvert was given to 20 healthy foals 7 days prior to being weaned; 20 healthy foals served as unvaccinated controls. Nasal secretions and blood were collected before vaccination, the day of weaning, and weekly thereafter for 3 weeks. Nasal secretions were tested by quantitative polymerase chain reaction (qPCR) for ...
Kim HJ, Yong TS, Shin MH, Lee KJ, Park GM, Suvonkulov U, Kovalenko D, Yu HS.Echinococcosis occurs mainly in areas with heavy livestock farming, such as Central Asia, America, and Australia. Echinococcus granulosus sensu lato (s.l.) infection causes echinococcosis in intermediate hosts, such as sheep, cattle, goats, camels, and horses. Numerous cases of echinococcosis occur in Uzbekistan as stock farming is a primary industry. Epidemiological and genetic studies of E. granulosus s.l. are very important for mitigating its impact on public health and the economy; however, there are no such studies on E. granulosus s.l. in Uzbekistan. In the present study, to determine wh...
Seo MG, Kwon OD, Kwak D.Lyme borreliosis is one of the most prevalent tick-borne infectious zoonotic diseases caused by spirochetes of the sensu lato group. The present study assessed the risk factors and prevalence of Lyme borreliosis in ticks parasitizing domestic and wild animals. A total of 589 ticks (329 tick pools) collected from animals were identified as , (85.7%), (10.0%), and (4.3%) using morphological and molecular methods in South Korea. In this study, the 5S-23S gene sequences of (6/329, 1.8%) were detected in ticks taken from mammals, including ticks from horses (2/147 pools, 1.4%), wild boar (1/19 ...
Paulino PG, Almosny N, Oliveira R, Viscardi V, Müller A, Guimarães A, Baldani C, da Silva C, Peckle M, Massard C, Santos H.This study aims to report the presence of Neorickettsia risticii DNA in blood samples from naturally infected horses in Rio de Janeiro, provide clinicopathological findings related to the infection, and report the phylogenetic diversity of the 16S rDNA of N. risticii in order to evaluate its heterogeneity. Real-time quantitative polymerase chain reaction (qPCR) was performed to investigate the presence of N. risticii in samples collected from horses (n = 187). Five positive samples were found in the molecular screening. Hypoalbuminemia and high levels of creatine kinase and lactate dehydro...
Kampen H, Holicki CM, Ziegler U, Groschup MH, Tews BA, Werner D.In 2018, West Nile virus (WNV) broke out for the first time in Germany, with continuation of the epidemic in 2019, involving birds, horses and humans. To identify vectors and characterize the virus, mosquitoes were collected in both years in zoological gardens and on a horse meadow immediately following the diagnosis of disease cases in birds and horses. Mosquitoes were identified and screened for WNV by qRT-PCR, with virus-positive samples being sequenced for the viral envelope protein gene. While no positive mosquitoes were found in 2018, seven mosquito pools tested positive for WNV in 2019 ...
Lab on a chipApril 26, 2020
Volume 20, Issue 9 1621-1627 doi: 10.1039/d0lc00304b
Sun F, Ganguli A, Nguyen J, Brisbin R, Shanmugam K, Hirschberg DL, Wheeler MB, Bashir R, Nash DM, Cunningham BT.Rapid, sensitive and specific detection and reporting of infectious pathogens is important for patient management and epidemic surveillance. We demonstrated a point-of-care system integrated with a smartphone for detecting live virus from nasal swab media, using a panel of equine respiratory infectious diseases as a model system for corresponding human diseases such as COVID-19. Specific nucleic acid sequences of five pathogens were amplified by loop-mediated isothermal amplification on a microfluidic chip and detected at the end of reactions by the smartphone. Pathogen-spiked horse nasal swab...
Springer A, Ehrmann C, Lembcke M, Roscher K, Strube C.Equine piroplasmosis, caused by the protozoan pathogens or , is endemic in many (sub-)tropical regions worldwide, including Southern Europe. In Germany, it mainly plays a role as an imported parasitosis. Nevetherless, tick species with known vector potential for equine piroplasms occur in Germany. Thus, a long-term establishment of autochthonous cycles after introduction via infected equids or ticks cannot be excluded. In the present case, 2 horses developed clinical infection after returning from a trail riding trip to southern France. During treatment, a feeding tick was discovered on one ...
Grewar JD, Porphyre T, Sergeant ES, Theresa Weyer C, Thompson PN.An African horse sickness (AHS) outbreak occurred in March and April 2016 in the controlled area of South Africa. This extended an existing trade suspension of live equids from South Africa to the European Union. In the post-outbreak period ongoing passive and active surveillance, the latter in the form of monthly sentinel surveillance and a stand-alone freedom from disease survey in March 2017, took place. We describe a stochastic scenario tree analysis of these surveillance components for 24 months, starting July 2016, in three distinct geographic areas of the controlled area. Given that AH...
Infectious causes of myositis are reported relatively uncommonly in horses. Among them, bacterial causes include subsp. , , spp. spp, and . Infection can be spread to muscles via haematogenous or extension from skin lesions. Parasitic myositis has also been documented. In this report, a 12 year-old Italian Quarter Horse mare presented with diffuse subcutaneous nodules and masses ranging from 2 × 3 to 5 × 20 cm in size, and adherent to subcutis and muscles that were first macroscopically and cytologically diagnosed as pyogranulomas. Subsequently, histological, molecular, bacteriological, a...
Johnson LM, Holcombe SJ, Shearer TR, Watson V, Gandy J, Southwood LL, Lynch TM, Schroeder EL, Fogle CA, Sordillo LM.Identifying therapies that mitigate ischemic colonic injury and improve mucosal healing and intestinal viability are crucial to improving survival in horses with ≥360° large colon volvulus (LCV). Ethyl pyruvate is the ethyl ester of pyruvate with diverse pharmacologic effects that limit ischemic injury and hasten intestinal mucosal repair in preclinical rodents, sheep and swine models. The objective of this study was to determine the effects of ethyl pyruvate on systemic indices of colon viability, expression of inflammatory genes in whole blood, morbidity and survival after surgical correc...
Song J, Song R, Wang P, Zhang Y, Yan Y, Zhou J, Chahan B, Liao M.The erythrocytic-stage surface protein equi merozoite antigen 1 (EMA-1) of Theileria equi is a major candidate for the development of a diagnostic antigen for equine piroplasmosis. In this study, BALB/c mice were immunized with purified recombinant EMA-1 to prepare monoclonal antibody (mAb) against T. equi EMA-1, and 1 mAb 5H2 was obtained that showed good reaction with infected red blood cells (RBC) in the indirect immunofluorescence assay (IFA). To develop a rapid serological detection method for T. equi infection in Xinjiang Uygur Autonomous Region, China, recombinant EMA-1 originating from...
Álvarez-Narváez S, Giguère S, Berghaus LJ, Dailey C, Vázquez-Boland JA.Conjugation is one of the main mechanisms involved in the spread and maintenance of antibiotic resistance in bacterial populations. We recently showed that the emerging macrolide resistance in the soilborne equine and zoonotic pathogen is conferred by the (46) gene carried on the 87-kb conjugative plasmid pRErm46. Here, we investigated the conjugal transferability of pRErm46 to 14 representative bacteria likely encountered by in the environmental habitat. mating experiments demonstrated conjugation to different members of the genus as well as to and spp. at frequencies ranging from ∼10...
Hurtado C, Torres R, Pérez-Macchi S, Sagredo K, Uberti B, de Souza Zanatto DC, Machado RZ, André MR, Bittencourt P, Müller A.Anaplasma phagocytophilum is the causative agent of equine granulocytic anaplasmosis (EGA). This study aimed to perform serological and molecular surveys of A. phagocytophilum in thoroughbred horses from racecourses in Chile. Additionally, hematological findings related to A. phagocytophilum molecular positivity were addressed, and phylogenetic analysis of selected positive samples was performed. Complete blood count and msp2 gene real-time PCR were performed in 457 thoroughbred horses from three racecourses located in three different cities of Chile (Santiago, Viña del Mar and Concepción). ...
Castro ER, Perez R, Rodriguez S, Bassetti L, Negro R, Vidal R.Equine influenza is one of the major respiratory infectious diseases in horses. In 2018, equine influenza virus (EIV) was confirmed as the cause of outbreaks of respiratory disease in horses in Chile and Argentina. In the same year, for the first time in Uruguay, EIV infection was confirmed by isolation and molecular analysis to be the cause of respiratory disease among hundreds of clinically affected thoroughbred horses in training and racing facilities. The virus was detected in nasopharyngeal swabs by a pan-reactive influenza type A realtime reverse transcription polymerase chain reaction (...
Laroucau K, Saqib M, Martin B, Deshayes T, Bertin C, Wernery U, Joseph S, Singha H, Tripathi BN, Beck C.Burkholderia mallei is the etiologic agent of glanders, an infectious disease of solipeds, with renewed scientific interest due to its increasing incidence in different parts of the world. More rapid, sensitive and specific assays are required by laboratories for confirmatory testing of this disease. A microsphere-based immunoassay consisting of beads coated with B. mallei recombinant proteins (BimA, GroEL, Hcp1, and TssB) has been developed for the serological diagnosis of glanders. The proteins' performance was compared with the OIE reference complement fixation test (CFT) and an indirect en...
Peck DE, Reeves WK, Pelzel-McCluskey AM, Derner JD, Drolet B, Cohnstaedt LW, Swanson D, McVey DS, Rodriguez LL, Peters DPC.Vesicular stomatitis viruses (VSVs) cause a condition known as vesicular stomatitis (VS), which results in painful lesions in equines, cattle, swine, and camelids, and when transmitted to humans, can cause flu-like symptoms. When animal premises are affected by VS, they are subject to a quarantine. The equine industry more broadly may incur economic losses due to interruptions of animal trade and transportation to shows, competitions, and other events. Equine owners, barn managers, and veterinarians can take proactive measures to reduce the risk of equines contracting VS. To identify appropria...
Hii C, Dhand NK, Toribio JLML, Taylor MR, Wiethoelter A, Schembri N, Sawford K, Kung N, Moloney B, Wright T, Field H, Schemann K.Hendra virus (HeV) is an emerging bat-borne virus endemic in Australia that can be transmitted from horses to humans and has a high fatality rate for horses and people. Controversy surrounding HeV risk mitigation measures have strained the veterinarian-horse owner relationship. This study aimed to characterise the veterinarian-horse owner relationship in general and also in the context of HeV by analysing data derived from the 'Horse Owners and Hendra Virus: A Longitudinal Study to Evaluate Risk' (HHALTER) study. Australian horse owners were recruited via emails, social media and word-of-mouth...
Dunuwille WMB, YousefiMashouf N, Balasuriya UBR, Pusterla N, Bailey E.Equid herpesvirus (EHV-1) infections in horses can lead to equine herpesvirus myeloencephalopathy (EHM), characterised by neurological clinical signs. The sporadic occurrence of the disease in horse herds suggests a host genetic component. A recent study reported an association between the occurrence of EHM and genetic markers on horse chromosome 6 (ECA6). Objective: To investigate the association of EHM with genetic host factors, especially with reference to the association reported for ECA6. Methods: Genome-wide association study (GWAS) was conducted based on 94 horses that had EHV-1 infecti...
Berryhill EH, Magdesian KG, Aleman M, Pusterla N.Equine coronavirus (ECoV) is a recently described enteric virus with worldwide outbreaks; however, there are little data available on clinical presentation, diagnosis, and outcome. The study objective was to document case management of ECoV in adult horses presented to a referral hospital and compare to a cohort of horses that tested negative for ECoV. A retrospective case series was performed based on positive real-time quantitative PCR results for ECoV on faeces from horses treated at the UC Davis Veterinary Medical Teaching Hospital from 1 March 2012 to 31 March 2018. Horses negative for EC...
Madani H, Casal J, Alba A, Allepuz A, Cêtre-Sossah C, Hafsi L, Kount-Chareb H, Bouayed-Chaouach N, Saadaoui H, Napp S.Antibodies against bluetongue virus were detected in cattle, sheep, goats, and camels in Algeria in 2008. Antibodies against epizootic hemorrhagic disease virus were detected in cattle, but antibodies against African horse sickness virus were not detected in horses and mules. Epizootic hemorrhagic disease in northern Africa poses a major risk for the European Union.
Sarkar S, Chelvarajan L, Go YY, Cook F, Artiushin S, Mondal S, Anderson K, Eberth J, Timoney PJ, Kalbfleisch TS, Bailey E, Balasuriya UB.Previous studies in our laboratory have identified equine CXCL16 (EqCXCL16) to be a candidate molecule and possible cell entry receptor for equine arteritis virus (EAV). In horses, the CXCL16 gene is located on equine chromosome 11 (ECA11) and encodes a glycosylated, type I transmembrane protein with 247 amino acids. Stable transfection of HEK-293T cells with plasmid DNA carrying EqCXCL16 (HEK-EqCXCL16 cells) increased the proportion of the cell population permissive to EAV infection from <3% to almost 100%. The increase in permissiveness was blocked either by transfection of HEK-EqCXCL16 cell...
Yates P, Mumford JA.To investigate the level of cross-protection induced by equine influenza H3N8 vaccines derived from different lineages, two studies have been carried out with ponies vaccinated with 'American-like' and 'European-like' vaccines and experimentally challenged with a European-like strain. The results demonstrated that equine influenza vaccines clearly protect against challenge with homologous virus if serum antibody titres are sufficiently high. On the other hand, protection is incomplete even when animals vaccinated with heterologous strains have comparative antibody levels. Nevertheless, the pro...
Ledbetter EC, Patten VH, Scarlett JM, Vermeylen FM.To determine in vitro susceptibility patterns of fungi associated with keratomycosis in horses in the northeastern United States and compare those patterns with results of studies from other geographic regions. Methods: Retrospective case series. Methods: 68 horses with keratomycosis. Methods: Medical records of horses with a clinical diagnosis of keratomycosis, positive results of corneal fungal cultures, and susceptibility data were reviewed from the years 1987 to 2006. Fungal identification and in vitro antifungal susceptibility test results were recorded. The percentage of susceptible isol...
Barragry TB.The avermectins were introduced in 1981 and constitute a potent new class of anthelmintic agents. They are naturally-derived products of microbial action displaying an exceptionally wide range of antiparasitic efficacy against internal and external parasites of domestic animals. This paper reviews their isolation and chemistry, mechanism of action, chemical efficacy and safety in cattle, sheep, swine, horses and dogs.
Abbas G, Ghafar A, Hurley J, Bauquier J, Beasley A, Wilkes EJA, Jacobson C, El-Hage C, Cudmore L, Carrigan P, Tennent-Brown B, Gauci CG, Nielsen MK....Cyathostomins are the most important and common parasitic nematodes of horses, with > 50 species known to occur worldwide. The frequent and indiscriminate use of anthelmintics has resulted in the development of anthelmintic resistance (AR) in horse nematodes. In this study we assessed the efficacy of commonly used anthelmintics against cyathostomins in Australian thoroughbred horses. Methods: Two drug efficacy trials per farm were conducted on two thoroughbred horse farms in the state of Victoria, Australia. In the first trial, the horses on Farm A were treated with single and combinations ...
Malekifard F, Tavassoli M, Yakhchali M, Darvishzadeh R.Equine piroplasmosis is a severe disease of horses caused by the intra-erythrocyte protozoan, Theileria equi and Babesia caballi. The aim of this study was to identify equine piroplasmosis based on molecular and morphometrical features in horses in suburb of Urmia, West Azerbaijan province, Iran. From April to September 2011, a total number of 240 blood samples were collected randomly from horses of 25 villages. The specimens were transferred to the laboratory and the blood smears stained with Geimsa, and the morphological and biometrical data of parasite in any infected erythrocyte were consi...
Hardy ME, Woode GN, Xu ZC, Williams JD, Conner ME, Dwyer RM, Powell DG.Equine group A rotaviruses isolated over a 10-year period in New York State, New Jersey, Kentucky, and Texas were compared serotypically and electropherotypically. All isolates were determined to be serotype 3 by reaction with hyperimmune antiserum to the serotype 3 H-2 strain of equine rotavirus. All displayed RNA electrophoretic migration patterns related to that of the H-2 strain but distinct from that of serotype 5 strain H-1. A serologic survey of 184 mares in Kentucky, which was done to determine the incidence of H-1 and H-2 infections, showed geometric mean serum neutralizing titers to ...
Shi N, Qiu X, Cao X, Mai Z, Zhu X, Li N, Zhang H, Zhang J, Li Z, Shaya N, Lu H, Jin N.The Getah virus (GETV), a mosquito-borne RNA virus, is widely distributed in Oceania and Asia. GETV is not the only pathogenic to horses, pigs, cattle, foxes and boars, but it can also cause fever in humans. Since its first reported case in Chinese mainland in 2017, the number of GETV-affected provinces has increased to seventeen till now. Therefore, we performed an epidemiologic investigation of GETV in the Xinjiang region, located in northwestern China, during the period of 2017-2020. ELISA was used to analyze 3299 serum samples collected from thoroughbred horse, local horse, sheep, goat, ca...
Pinho MD, Erol E, Ribeiro-Gonçalves B, Mendes CI, Carriço JA, Matos SC, Preziuso S, Luebke-Becker A, Wieler LH, Melo-Cristino J, Ramirez M.The pathogenic role of beta-hemolytic Streptococcus dysgalactiae in the equine host is increasingly recognized. A collection of 108 Lancefield group C (n = 96) or L (n = 12) horse isolates recovered in the United States and in three European countries presented multilocus sequence typing (MLST) alleles, sequence types and emm types (only 56% of the isolates could be emm typed) that were, with few exceptions, distinct from those previously found in human Streptococcus dysgalactiae subsp. equisimilis. Characterization of a subset of horse isolates by multilocus sequence analysis (MLSA) a...
Escobar TA, Dowich G, Dos Santos TP, Zuravski L, Duarte CA, Lübeck I, Manfredini V.Leishmaniosis, zoonosis that produces significant public health impacts, is caused by Leishmania infantum. Canines are the main domestic reservoir and, besides humans, other species of mammals could be infected when living in endemic areas. In this study, we detected equine Leishmania infantum infections in a canine visceral leishmaniosis transmission area and evaluated the clinical, haematological, biochemical and oxidative stress disorders. This study was conducted in Uruguaiana, Rio Grande do Sul, south of Brazil. Peripheral blood samples were collected from 124 animals (98 horses and 26 do...
Friday PA, Scarratt WK, Elvinger F, Timoney PJ, Bonda A.An outbreak of neurologic disease associated with serologic evidence of equine herpesvirus type 1 (EHV-1) infection occurred in a herd of 46 riding school horses. Ataxia and paresis were observed in 14 geldings and 5 barren mares. Eight affected horses had distal limb edema, 1 horse had a head tilt, and 3 others had urinary incontinence. Other clinical signs included fever, depression, and inappetance in 30 horses. Seven horses with neurologic signs were treated with acyclovir. Serum neutralizing antibody titers against EHV-1 increased 4-fold between acute and convalescent samples or exceeded ...
Dietz WH, Galindo P, Johnson KM.In late June 1973, a small outbreak of equine encephalitis caused by eastern equine encephalomyelitis (EEE) virus occurred in the Republic of Panama. At least 100 horses were affected by the disease and 40 died. More than 1,700 human sera were obtained from areas of virus activity but no serological evidence for infection was found. Four isolates of EEE virus were recovered, one of which was from a small pool of Culex taeniopus mosquitoes. Serologic studies of infected horses and classification by the short incubation hemagglutination-inhibition tests revealed that these isolates were South Am...
Quinlivan M, Nelly M, Prendergast M, Breathnach C, Horohov D, Arkins S, Chiang YW, Chu HJ, Ng T, Cullinane A.Most studies of the cytokine response to influenza virus infection have been carried out in human, porcine and murine models, however the data available on equine cytokines is limited. An experimental challenge study was undertaken in unvaccinated naïve horses and horses vaccinated with a commercial inactivated influenza vaccine. The humoral antibody response to vaccination and virus challenge was measured by single radial haemolysis (SRH) assay and clinical signs of influenza and viral shedding were monitored post-challenge. Levels of three equine pro-inflammatory cytokines interleukin (IL)-...
Plummer G, Goodheart CR, Studdert MJ.Equine herpesviruses with a deoxyribonucleic acid density of 1.716 to 1.717 g/cm(3) were compared with one another by the plaque-reduction test and by the rate of development of cytopathic effect as indicated by plaque size in rabbit kidney cultures. Of the 19 isolates studied, the 9 which had already been tentatively labeled equine abortion viruses were serologically similar to one another; each of them grew more quickly than did any of the other 10 isolates although the mean plaque sizes formed a series of gradations with no clear hiatus which would permit the unequivocal delineation of the ...
Traversa D, Otranto D, Milillo P, Latrofa MS, Giangaspero A, Di Cesare A, Paoletti B.In order to evaluate infection occurrence and the potential zoonotic role of horse isolates of Giardia duodenalis, 431 individual fecal samples were genetically characterized by PCR tests -coupled sequencing and phylogenetic analysis. Thirty-seven (8.6%) animals resulted infected by different Assemblage. The presence of sub-Assemblage was assessed by characterizing the β-giardin gene for 16 of the 37 positive horses. Ten isolates showed 99.6% to 100% homology with the sub-Assemblage described as B1-2 and B1-6, three Assemblage A showed 99.8% homology with sub-Assemblage A1, while one Assembla...
Tirosh-Levy S, Gottlieb Y, Apanaskevich DA, Mumcuoglu KY, Steinman A.Ticks are important ectoparasites of horses that can affect animal welfare and vector several infectious, including zoonotic, diseases. In order to investigate the species distribution, epidemiology and seasonal dynamics of ticks infesting horses in Israel, 3267 ticks were collected from 396 horses in 24 farms across the country from July 2014 to June 2015. Results: Ticks were found on 50% of the farms and on 25% of the horses, with Hyalomma being the most prevalent genus (70% of ticks). Pasture was the most prominent risk factor for tick infestation (99% of ticks, P < 0.001), and is repres...
Butler CM, Sloet van Oldruitenborgh-Oosterbaan MM, Stout TA, van der Kolk JH, Wollenberg Lv, Nielen M, Jongejan F, Werners AH, Houwers DJ.Equine piroplasmosis (EP) has not been considered indigenous in The Netherlands. However, following the detection of an apparently indigenous subclinical Babesia caballi infection in a horse on Schouwen-Duiveland (an island in the Zeeland Province), a survey was undertaken between May and September 2010 to assess the prevalence of the causative agents of EP in the South-West of The Netherlands. Blood samples from 300 randomly selected horses were tested for specific antibodies against Theileria equi and B. caballi using an indirect fluorescence antibody test (IFAT), and for parasite DNA using ...
Bunpapong N, Charoenkul K, Nasamran C, Chamsai E, Udom K, Boonyapisitsopa S, Tantilertcharoen R, Kesdangsakonwut S, Techakriengkrai N, Suradhat S....To investigate an outbreak of African horse sickness (AHS) on a horse farm in northeastern Thailand, we used whole-genome sequencing to detect and characterize the virus. The viruses belonged to serotype 1 and contained unique amino acids (95V,166S, 660I in virus capsid protein 2), suggesting a single virus introduction to Thailand.
Schwarz ER, Long MT.West Nile virus (WNV) neuroinvasive disease threatens the health and well-being of horses and humans worldwide. Disease in horses and humans is remarkably similar. The occurrence of WNV disease in these mammalian hosts has geographic overlap with shared macroscale and microscale drivers of risk. Importantly, intrahost virus dynamics, the evolution of the antibody response, and clinicopathology are similar. The goal of this review is to provide a comparison of WNV infection in humans and horses and to identify similarities that can be exploited to enhance surveillance methods for the early dete...
Astakhova NM, Perelygin AA, Zharkikh AA, Lear TL, Coleman SJ, MacLeod JN, Brinton MA.Toll-like receptors 3, 7, and 8 (TLR3, TLR7, and TLR8) were studied in the genomes of the domestic horse and several other mammals. The messenger RNA sequences and exon/intron structures of these TLR genes were determined. An equine bacterial artificial chromosome clone containing the TLR3 gene was assigned by fluorescent in situ hybridization to the horse chromosomal location ECA27q16-q17 and this map location was confirmed using an equine radiation hybrid panel. Direct sequencing revealed 13 single-nucleotide polymorphisms in the coding regions of the equine TLR 3, 7, and 8 genes. Of these p...
Morton AC, Begg AP, Anderson GA, Takai S, Lämmler C, Browning GF.Pulsed-field gel electrophoresis of restriction endonuclease-digested genomic DNA from a large collection of clinical isolates of Rhodococcus equi, an important pathogen of foals, was used to compare strain distribution between farms and over time. Forty-four strains were found among 209 isolates, with 5 of these accounting for over half the isolates and the 22 strains isolated more than once accounting for 90% of the isolates. The average genotypic diversity on each farm and in each year was found to be less than the genotypic diversity of the isolates taken as a whole, with 5.2% of the total...
Dubey JP, Streitel RH, Stromberg PC, Toussant MJ.Hearts, diaphragms, esophagi, and spinal cords from 266 horses were obtained at slaughter in Creston, Ohio. Tissues were examined microscopically for Sarcocystis in sections, digested in trypsin to obtain bradyzoites, and fed to 10 dogs and 10 cats. Intramuscular cysts were found in selections of two hearts from 57 horses and four esophagi from 107 horses. The cysts were up to 900 micron long and up to 70 micron wide. The cyst wall was 1 to 2 micron thick and cross-striated. The enclosed bradyzoites were banana-shaped, 15 to 20 by 20 to 3 micron, and contained several PAS-positive granules. Br...
Reed Z, Thomasy SM, Good KL, Maggs DJ, Magdesian KG, Pusterla N, Hollingsworth SR.Equine keratomycosis in the western USA has received little study, probably owing to its low prevalence. Objective: To determine clinical features, predominant fungal isolates, treatment modalities and outcomes of horses with keratomycosis in California and compare these with results from different geographic regions. Methods: Records of horses presented to the University of California-Davis Veterinary Medical Teaching Hospital (UCD-VMTH) with confirmed keratomycosis between 1987 and 2010 were reviewed for this retrospective study. Information retrieved from the record included background, oph...