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.
McGurrin MK, Vengust M, Arroyo LG, Baird JD.An outbreak of protein-losing enteropathy associated with Lawsonia intracelluaris infection was diagnosed in 6 standardbred foals from a farm in Ontario. Wildlife exposure may have been involved in the perpetuation of disease in this outbreak. The clinical presentation, treatment, outcomes, and pathological findings are described. Éclosion d’infections à Lawsonia intracellularis dans un troupeau de Standardbred en Ontario. Une éclosion d’entéropathies exsudatives associée à une infection à Lawsonia intracellularis a été diagnostiquée chez 6 poulains Standardbred d’une ferme de ...
Epp T, Waldner C, Leighton FA, Berke O, Townsend HG.The primary objectives of this study were to determine the seroprevalence of West Nile virus (WNV) infection of horses in Saskatchewan in 2003 and to identify risk factors for the infection. Blood samples were collected in August and October from 212 horses in 20 herds in 5 geographic zones. After accounting for within-herd clustering, the proportion of horses that had been infected with WNV, as determined by IgG and IgM antibody response, was 55.7% (95% confidence interval, 44.9% to 65.8%). The proportion of antibody-positive horses differed among herds (0% to 100%) and across ecoregions (20%...
Alvarez I, Gutierrez G, Ostlund E, Barrandeguy M, Trono K.We analyzed the performance of a single-band Western blot (WB) test using recombinant p26 (rp26) capsid protein of equine infectious anemia virus. According to the results obtained, the rp26 WB test is a reliable confirmatory diagnostic tool to be used as a complementary test after an enzyme-linked immunosorbent assay or agar gel immunodiffusion test yielding doubtful results.
Attoui H, Sailleau C, Mohd Jaafar F, Belhouchet M, Biagini P, Cantaloube JF, de Micco P, Mertens P, Zientara S.The complete nucleotide sequence of Middelburg virus (MIDV) was determined for strain MIDV-857 from Zimbabwe. The isolation of this virus in 1993 from a horse that died showing severe clinical signs represents the first indication that MIDV can cause severe disease in equids. Full-length cDNA copies of the viral genome were successfully synthesized by an innovative RT-PCR amplification approach using an 'anchor primer' combined with the SMART methodology described previously for the synthesis of full-length cDNA copies from genome segments of dsRNA viruses. The MIDV-857 genome is 11,674 nt, ex...
Alhassan A, Iseki H, Kim C, Yokoyama N, Igarashi I.Rapid, efficient, and reproducible procedures for isolating DNA before PCR gene amplification are essential for the diagnosis of piroplasms. In this study, we evaluated the ease and reliability of detecting Theileria equi by PCR using pre-extracted DNA samples (by QIAamp DNA Mini Kit and phenol-chloroform methods) compared with blood spotted on FTA cards as PCR templates. Although minimal variations in limit of detection were observed among the methods compared, overall, the use of pre-extracted DNA samples and blood spotted on FTA cards had comparable detection limits. These results indicate ...
Schwarz S, Alesík E, Grobbel M, Lübke-Becker A, Werckenthin C, Wieler LH, Wallmann J.A total of 500 streptococci from two indications of swine (beta-haemolytic streptococci from infections of the urinary/genital tract including strains from the mastitis metritis agalactia syndrome as well as S. suis from infections of the central nervous system and the musculoskeletal system), two indications of horses (S. equi from respiratory tract infections and beta-haemolytic streptococci from infections of the genital tract), as well as three indications of dogs and cats (beta-haemolytic streptococci from infections of the respiratory tract, the urinary/genital tract, and skin/ear/mouth)...
Samina I, Havenga M, Koudstaal W, Khinich Y, Koldijk M, Malkinson M, Simanov M, Perl S, Gijsbers L, Weverling GJ, Uytdehaag F, Goudsmit J.Studies were performed with an inactivated vaccine against the mosquito-borne flavivirus, West Nile virus (WNV). The mammalian cell line, PER.C6, was selected as the platform for WNV growth since both the neurovirulent strains NY99 and ISR98 that cause epidemics in humans and high mortality in geese, respectively, could be propagated to high titers (10(9) to 10(10)TCID(50)/ml) on these cells. Based on the high DNA homology of the WNV envelope (E) protein and non-structural protein 5 (NS5), and identical neurovirulence in mice and geese, we concluded that NY99 and ISR98 viruses are closely rela...
de Oliveira Lima AN, da Silva Santos S, Herrera HM, Gama C, Cupolillo E, Jansen AM, Fernandes O.The protozoan Trypanosoma evansi is described as presenting high morphological and genetic similarities among the isolates despite its biological heterogeneity and wide geographical distribution. PCR amplification of the internal transcribed spacers of the ribosomal gene in combination with the coding region of the 5.8S ribosomal subunit further submitted to restriction enzymes digestion were carried out in DNAs extracted from 41 T. evansi strains isolated from horses, dogs, coatis and capybaras from two distinct regions of the Brazilian Pantanal. We also used one T. evansi isolate from Africa...
Pacini S, Spinabella S, Trombi L, Fazzi R, Galimberti S, Dini F, Carlucci F, Petrini M.It has been proven that mesenchymal stromal cells (MSCs) can differentiate into tenocytes. Attempts to repair tendon lesions have been performed, mainly using scaffold carriers in experimental settings. In this article, we describe the clinical use of undifferentiated MSCs in racehorses. Significant clinical recovery was achieved in 9 of 11 horses evaluated using ultrasound analysis and their ability to return to racing. Our results show that the suspension of a small number of undifferentiated MSCs may be sufficient to repair damaged tendons without the use of scaffold support. Ultrasound sca...
Oncel T, Vural G, Gicik Y, Arslan MO.This study was carried out in order to detect antibodies to Babesia (Theileria) equi in the local breed of horses in the province of Kars, Turkey. A total of 108 serum samples from apparently healthy horses in eight villages were examined for B. equi antibodies by an indirect immunofluorescent antibody test (IFAT). Of the 108 samples tested, 27 (25%) were found to be seropositive. The horses sampled in Aydinalan village had the highest prevalence (50.0%) of Babesia equi infection while the lowest prevalence was found among horses from Bayraktar village (12.5%). Statistically significant differ...
Maeda K, Yasumoto S, Tsuruda A, Andoh K, Kai K, Otoi T, Matsumura T.In the present study, an equine-derived cell line was established by transfecting primary fetal horse kidney (FHK) cells with expression plasmid encoding simian virus 40 (SV40) large T antigen and then cloning them by limiting dilution. The cloned cell line, named FHK-Tcl3, grew well and could be propagated over 30 times by splitting them 1:3. Equine herpesvirus (EHV)-1 and EHV-4 replicated well in FHK-Tcl3. EHV-2 and EHV-4 were isolated from samples collected from horses in the field using FHK-Tcl3, and EHV-3 also propagated in FHK-Tcl3. These results indicated that this novel cell line, FHK-...
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...
Martens RJ, Mealey K, Cohen ND, Harrington JR, Chaffin MK, Taylor RJ, Bernstein LR.To determine the pharmacokinetics of gallium maltolate (GaM) after intragastric administration in healthy foals. Methods: 6 healthy neonatal foals. Methods: Each foal received GaM (20 mg/kg) by intragastric administration. Blood samples were obtained before (time 0) and at 0.25, 0.5, 1, 2, 4, 8, 12, 24, 36, and 48 hours after GaM administration for determination of serum gallium concentrations by use of inductively coupled plasma mass spectroscopy. Results: Mean +/- SD pharmacokinetic variables were as follows: peak serum gallium concentration, 1,079 +/- 311 ng/mL; time to peak serum concentra...
Vercauteren G, van der Heyden S, Lefère L, Chiers K, Laevens H, Ducatelle R.This report concerns 2 horses that suffered typical clinical signs of atypical myopathy (AM) and equine grass sickness (EGS) concurrently. Clinical details and pathological lesions of the cases are described. EGS and AM are relatively rare diseases and the concurrency of the diseases in the same animals is therefore considered unlikely to be a coincidence. However, it is not suggested that the evidence shows a common aetiology but rather the existence of common predisposing causes.
Daly JM, Sindle T, Tearle J, Barquero N, Newton JR, Corning S.Surveillance of equine influenza viruses has suggested that strains included in currently licensed vaccines are a poor match for those predominantly circulating in the field. Objective: To assess the ability of Duvaxyn IE-T Plus to provide cross protection against the newly evolved South Africa/4/03 (H3N8) strain of equine influenza virus. Methods: The vaccine efficacy was evaluated by challenge infection with influenza strain A/eq/South Africa/4/03 (H3N8) 2 weeks after a primary course of 2 vaccinations with Duvaxyn IE-T Plus given at a 4-week interval. The outcome of challenge in vaccinated ...
Garmashova N, Atasheva S, Kang W, Weaver SC, Frolova E, Frolov I.The encephalitogenic New World alphaviruses, including Venezuelan (VEEV), eastern (EEEV), and western equine encephalitis viruses, constitute a continuing public health threat in the United States. They circulate in Central, South, and North America and have the ability to cause fatal disease in humans and in horses and other domestic animals. We recently demonstrated that these viruses have developed the ability to interfere with cellular transcription and use it as a means of downregulating a cellular antiviral response. The results of the present study suggest that the N-terminal, approxima...
Ljungberg K, Whitmore AC, Fluet ME, Moran TP, Shabman RS, Collier ML, Kraus AA, Thompson JM, Montefiori DC, Beard C, Johnston RE.A novel genetic vaccine that is based on a Venezuelan equine encephalitis virus (VEE) replicon launched from plasmid DNA is described. The plasmid encodes a VEE replicon under the transcriptional control of the cytomegalovirus immediate-early promoter (VEE DNA). The VEE DNA consistently expressed 3- to 15-fold more green fluorescent protein in vitro than did a conventional DNA vaccine. Furthermore, transfection with the DNA-launched VEE replicon induced apoptosis and type I interferon production. Inoculation of mice with VEE DNA encoding human immunodeficiency virus type 1 gp160 significantly ...
Contreras M, Morales A, García-Amado MA, De Vera M, Bermúdez V, Gueneau P.To assess the presence of Helicobacter DNA in the gastric mucosa Thoroughbred horses. Results: Squamous and glandular mucosa samples were collected from 20 Thoroughbreds. None of these horses had shown any clinical symptoms of gastrointestinal disease. Necropsy tissues were analysed using histopathological techniques and a Helicobacter genus-specific PCR assay followed by sequencing of the amplicons. Seven horses were diagnosed with gastric ulceration, five with gastritis and six with both pathologies. Only two horses had a healthy gastric mucosa. Helicobacter-like DNA was detected in two out ...
Bamberg WM, Pape WJ, Beebe JL, Nevin-Woods C, Ray W, Maguire H, Nucci J, Massung RF, Gershman K.Coxiella burnetii is a bacterium located worldwide that can cause Q fever when inhaled. We describe an outbreak of Q fever associated with a horse-boarding ranch that had acquired two herds of goats. We conducted case finding and cohort studies among persons who boarded horses on the ranch and ranchers and among residents in the surrounding community, and conducted sampling of the goats and environment, to determine risk factors for infection and guide public health interventions. Sixty-six ranchers and persons who boarded horses on the ranch were interviewed; 62 (94%) were not professional ra...
Damiani AM, Scicluna MT, Ciabatti I, Cardeti G, Sala M, Vulcano G, Cordioli P, Martella V, Amaddeo D, Autorino GL.During local respiratory disease outbreaks, occurring in 2003 and 2004 in horse training stables within race-tracks in Rome, and on a stud horse farm in Bari in 2005, four strains of equine influenza (EI) virus were isolated. All outbreaks occurred in flu-vaccinated horses. Here, we are reporting the results of the genetic characterization of these isolates, together with that of another EI virus strain isolated in 1999 from a dead foal presenting pulmonary lesions. Alignment and phylogenetic analyses were carried out using the haemagglutinin amino acid sequences. The Rome and Bari isolates we...
Lian M, Warner RD, Alexander JL, Dixon KR.In 2002, West Nile virus (WNV) first appeared in Texas. Surveillance data were retrospectively examined to explore the temporal and spatial characteristics of the Texas equine WNV epidemic in 2002. Using Geographic Information Systems (GIS) and the Spatial and Space-Time Scan (SaTScan) statistics, we analyzed 1421 of the reported equine WNV cases from six contiguous state Health Service Regions (HSRs), comprising 158 counties, in western, northern, central and eastern Texas. Results: Two primary epidemic peaks occurred in Epidemiological (Epi) week 35 (August 25 to 31) and Epi week 42 (October...
Yörük I, Deger Y, Mert H, Mert N.The serum concentrations of copper, zinc, iron, and cobalt and copper/zinc ratio were investigated in horses infected with equine herpesvirus-1 (EHV-1). Nine horses were naturally infected with the virus and nine healthy horses served as controls. The concentrations of copper, zinc, iron, and cobalt were determined spectrophotometrically in the blood serum of all horses. The results were (expressed in micrograms per deciliters) copper 2.80 +/- 0.34 vs 1.12 +/- 0.44, zinc 3.05 +/- 0.18 vs 0.83 +/- 0.06, iron 2.76 +/- 0.17 vs 3.71 +/- 0.69, cobalt 0.19 +/- 0.37 vs 0.22 +/- 0.45, and copper/zinc ...
Mankoc S, Hostnik P, Grom J, Toplak I, Klobucar I, Kosec M, Barlic-Maganja D.In the present study, a new one-step real-time reverse transcription-polymerase chain reaction (RT-PCR) strategy with minor-groove-binder (MGB) technology for the detection of EAV from 40 semen samples of Slovenian carrier stallions was tested. A novel MGB probe (EAVMGBpr) and a reverse primer (EAV-R) based on the multiple sequence alignment of 49 different EAV strain sequences of the highly conserved ORF7 (nucleocapsid gene) were designed. The performance of the assay was compared with different molecular detection methods. Three different primer pairs targeting the ORF1b and ORF7 were used, ...
Rendle DI, Cottle HJ, Love S, Hughes KJ.In equids, chorioptic mange is a common dermatitis for which there are no licensed medications in the uk. Doramectin and fipronil are licensed for the control of ectoparasites in other species and were evaluated for the treatment of 17 cases of chorioptic mange in 13 equids. Equids were included if clinical findings were indicative of chorioptic mange, chorioptes mites were positively identified and concurrent disease that could affect response to disease was not evident. A random number table was used to allocate subjects to receive doramectin (group D, eight animals) or fipronil (group F, ni...
Nolen-Walston RD, D'Oench SM, Hanelt LM, Sharkey LC, Paradis MR.An 11-year-old Hanoverian-cross gelding was evaluated because of acute onset of ataxia, recumbency, and fever. At the stable, this and other horses had recently been infested with ticks. Results of analysis of a sample of CSF were within reference limits, but hematologic abnormalities included lymphopenia, thrombocytopenia, mild anemia, and intracytoplasmic inclusion bodies in neutrophils that were consistent with Anaplasma phagocytophilum (previously Ehrlichia equi). Results of serum biochemical analyses were characteristic of infection and included high, unconjugated bilirubin concentration....
Boyle AG, Rankin SC, O'Shea K, Stefanovski D, Peng J, Song J, Bau HH.Rapid point-of-care (POC) detection of Streptococcus equi subsp. equi (S. equi) would theoretically reduce the spread of strangles by identifying index and carrier horses. Objective: That the eqbE isothermal amplification (LAMP) assay, and the same eqbE LAMP assay tested in a microfluidic device format, are comparable to a triplex real-time quantitative polymerase chain reaction (qPCR) assay that is commonly used in diagnostic labs. Methods: Sixty-eight guttural pouch lavage (GPL) specimens from horses recovering from strangles. Methods: Guttural pouch lavage specimens were tested for S. equi ...
Uchida-Fujii E, Niwa H, Kanai K, Kinoshita Y, Kuroda T, Nukada T, Ueno T.Methicillin-resistant Staphylococcus aureus (MRSA) has often been isolated from livestock and companion animals, including horses. Seven cases of MRSA infection in Thoroughbred racehorses were observed in an equine hospital in Japan in 2020. In this study, MRSA isolates from these seven horses and nine veterinarians in the equine hospital were studied to examine their genetic relatedness and evaluate the possibility of MRSA transmission. The MRSA isolates were subjected to whole-genome sequencing for multi-locus sequence typing, S. aureus protein A (spa) typing, staphylococcal cassette chromos...
Razmi GR, Abedi V, Yaghfoori S.Toxoplasmosis is an important zoonotic disease with worldwide distribution. The infection is observed in an unusually wide range of warm-blooded animals, including most of the livestock and humans. Many studies have shown high prevalence of toxoplasmosis in man and animals in Iran. The present study was conducted to investigate the seroprevalence of toxoplasmosis in Turkoman horses in the North Khorasan Province. During 2011-2012, 100 blood samples from horses were collected and tested for antibodies against toxoplasmosis using indirect fluorescent antibody test. The seroprevalence of toxoplas...
Hoberg EP, Miller S, Brown MA.We report the first documented case of autochthonous echinococcosis in a horse of North American origin. Three fully mature and viable unilocular hydatid cysts of Echinococcus granulosus (Batsch, 1786) were an incidental finding at necropsy in the liver of a 14-yr-old gelding thoroughbred that had been foaled in Virginia and raised in Maryland. Protoscolices were armed with 2 rows of 28-37 rostellar hooks; small hooks measured 23-30 microns; large hooks measured 26-33 microns. Morphologically, these were compatible with rostellar armature considered typical for the equine strain of E. granulos...
Milwid RM, O'Sullivan TL, Poljak Z, Laskowski M, Greer AL.Contact networks can be used to assess disease spread potential within a population. However, the data required to generate the networks can be challenging to collect. One method of collecting this type of data is by using radio-frequency identification (RFID) tags. The OpenBeacon RFID system generally consists of tags and readers. Communicating tags should be within 10m of the readers, which are powered by an external power source. The readers are challenging to implement in agricultural settings due to the lack of a power source and the large area needed to be covered. OpenBeacon firmware wa...
Lew AM, Thomas LM, Huntington PJ.Sera of sixteen horses with clinical signs of EIA from six different outbreaks and sera of 100 uninfected horses were used to validate an ELISA for EIA diagnosis. The antigen used was a recombinant protein derived from the amino-terminal portion of the transmembrane envelope protein of EIA (gp45). Reactivity between positive and negative sera could be clearly distinguished. Comparison with the traditional agar gel immunodiffusion test (commonly called the Coggins test) showed that the ELISA was superior in sensitivity. Comparison of this ELISA with the FAST-ELISA system showed that the latter ...
Suleman O.Researchers conducted a survey study of 59,598 households in 3 major socioeconomic groups (urban slums, rural agricultural areas, and rural cattle and horse raising areas) in the Punjab province of Pakistan to estimate mortality from neonatal tetanus and to develop a strategy for its control. The investigators learned of 13,831 live births. 724 of these died in the 1st month of life with 432 (60%) dying from neonatal tetanus. Village untrained "dai" or trained midwives delivered all infants in all 3 areas. Often these deliverers placed cow dung on the stump of the severed umbilical cord and us...
Loroño-Pino MA, Farfan-Ale JA, Garcia-Rejon JE, Lin M, Rosado-Paredes E, Puerto FI, Bates A, Root JJ, Franklin AB, Sullivan HJ, Blitvich BJ.No abstract available
Wolny-Koładka K.The aim of this study was to assess the microbiological quality of air in three horse riding centers differing in the horse keeping systems. The air samples were collected in one facility with free-range horse keeping system and two with box stalls of different sizes. The samples were collected over a period of 3 years (2015-2017), four times per year (spring, summer, autumn, winter) to assess the effect of seasonal changes. The prevalence of aerobic mesophilic bacteria, mold fungi, actinomycetes, Staphylococcus spp., and Escherichia coli was determined by the air collision method on Petri di...
Oncel T, Vural G, Gicik Y, Arslan MO.This study was carried out in order to detect antibodies to Babesia (Theileria) equi in the local breed of horses in the province of Kars, Turkey. A total of 108 serum samples from apparently healthy horses in eight villages were examined for B. equi antibodies by an indirect immunofluorescent antibody test (IFAT). Of the 108 samples tested, 27 (25%) were found to be seropositive. The horses sampled in Aydinalan village had the highest prevalence (50.0%) of Babesia equi infection while the lowest prevalence was found among horses from Bayraktar village (12.5%). Statistically significant differ...
Waller A., head of bacteriology at the AHT, describes the causative agent of strangles in horses, and discusses progress with the latest research aimed at improving vaccines against this global disease.
Donnelly J, Joyner LP, Frank C.Racehorses imported into Kuwait were tested for serum antibodies to Babesia equi and B. caballi by complement fixation (CF) and indirect fluorescent antibody (IFA) tests. The prevalence of B. equi was high (77.1% by IFA) whereas that of B. caballi was much lower (11.4%). Data for B. equi showed that infection was acquired after about 6 months at risk and that in the following 12 months animals had antibody levels detectable by both CF and IFA tests by 24 months the CF reaction was no longer detectable. Estimates of incidence and inoculation rates were calculated and found to be consistent with...
Böhnel H, Wernery U, Gessler F.Botulism is caused by different types of Clostridium botulinum, a soil bacterium. Equine grass sickness (equine dysautonomia) is suspected of being a clinical form of this disease. On a stud where this disease occurred twice within 8 months, grass and soil samples and necropsy specimens of one horse were tested for the presence of bacterial forms and toxin of C. botulinum. Different types and type mixtures (A-E) of C. botulinum and botulinum neurotoxin were found. For the first time, it has been shown that green grass blades contain botulinum toxin. The results support the hypothesis that equi...
Love S, Burden FA, McGirr EC, Gordon L, Denwood MJ.Domesticated grazing animals including horses and donkeys are frequently housed using deep litter bedding systems, where it is commonly presumed that there is no risk of infection from the nematodes that are associated with grazing at pasture. We use two different approaches to test whether equids could become infected with cyathostomines from the ingestion of deep litter straw bedding. Two herbage plot studies were performed in horticultural incubators set up to simulate three straw bedding scenarios and one grass turf positive control. Faeces were placed on 16 plots, and larval recoveries pe...