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.
MacNeill AL, Micheloud JF, Parvin R, Gjessing M, Airas NA, Sant'Ana FJF, Adamek M.Zoonotic poxviruses, including monkeypox virus (MPV), the causative agent for Mpox disease, have gained significant media and scientific attention due to recent outbreaks in human populations across the globe. The increase in human cases of poxvirus infection is not unexpected, as routine vaccination against smallpox (a disease caused by the poxvirus variola virus, which cross protects against other orthopoxviruses) was discontinued in the 1980s after its eradication. Large numbers of vertebrate and invertebrate species are susceptible to infection by . Clinical signs and histologic lesions ca...
Maloney SM, Shaw TM, Nennig KM, Larsen MS, Shah A, Kumar A, Marcotrigiano J, Grove J, Snijder EJ, Kirchdoerfer RN, Bailey AL.Arteriviruses are a family of single-stranded, positive-sense RNA (+ssRNA) viruses that infect diverse animal hosts. Many arteriviruses are macrophage-tropic, consistent with their utilization of the macrophage-specific molecule CD163 as a receptor. However, the horse arterivirus (equine arteritis virus, EAV), which infects additional cell types beyond macrophages, does not utilize CD163 in its entry mechanism. Here, we use a genome-wide CRISPR knockout screen to identify alternative receptors that could explain this discrepancy in arterivirus receptor utilization and tropism, identifying the ...
da Silveira BP, Kahn SK, Legere RM, Bray JM, Cole-Pfeiffer HM, Golding MC, Cohen ND, Bordin AI.Using a horse foal model, we show that enteral immunization of newborn foals with Rhodococcus equi overcomes neonatal vaccination challenges by reprogramming innate immune responses, inducing R. equi-specific adaptive humoral and cell-mediated immune responses and protecting foals against experimental pneumonia challenge. Foals were immunized twice via gavage of R. equi (immunized group) or saline (control group) at ages 1 and 3 days. At age 28 days, all foals were challenged intrabronchially with R. equi. Post-challenge, all 5 immunized foals remained healthy, whereas 67% (4/6) of control foa...
Mizuguchi Y, Niwa H, Inoue H, Iwano H.Hypoproteinaemia/hypoalbuminaemia is a typical clinical feature of Lawsonia intracellularis infection in horses, but amino acid perturbations in these horses have not been investigated. Objective: Clarifying blood amino acid levels in horses suffering from Lawsonia intracellularis infection to identify novel aspects of the disease. Methods: Retrospective observational study. Methods: A total of 135 serum samples collected from horses from 59 farms were used in this study. Horses diagnosed with the clinical form of equine proliferative enteropathy (EPE) were enrolled as a clinical group (n =â...
Duaso J, Perez-Ecija A, MartÃnez E, Navarro A, De Las Heras A, Mendoza FJ.Equine piroplasmosis (EP) is a tick-borne disease affecting equids worldwide. Diagnosis is based on direct methods (blood smear or PCR) or indirect methods (serology); however, these techniques yield positive and negative results. Thus, an alternative, reliable, rapid, and cost-effective complementary tool, such as hematologic parameters and newly described hematologic ratios, could help in the EP diagnosis. This study describes the changes induced by piroplasmosis infection on hematologic parameters and ratios in horses. PCR-positive horses exhibited anemia and thrombocytopenia, whereas PCR...
Pinn-Woodcock TL, Aprea MS, Lejeune M, Tomlinson JE.A common diagnostic approach for febrile horses is to test for a panel of potential pathogens. Panels are curated by expert opinion and vary between diagnostic laboratories. Objective: To report the results of a newly developed equine fever diagnostic panel (EFDP) between 2019 and 2023 and evaluate the frequency of positive results. Methods: Retrospective descriptive study. Methods: The EFDP requires submission of whole blood, nasal swab, and faecal samples, and includes PCR tests for 12 pathogens that can present as fever without localising signs of illness or infection. Submission metadata a...
Ballados-González GG, Cruz-Romero A, MartÃnez-Hernández JM, Aguilar-DomÃnguez M, Vieira RFC, Grostieta E, Becker I, Sánchez-Montes S.Hemotropic mycoplasmas (HM) are emerging pathogens known to infect a wide range of mammals, including ungulates like horses. These infections can lead to severe haematological conditions, posing a threat to animal health and welfare. Recent studies have begun shedding light on the prevalence and impact of HM on horse populations worldwide. For instance, in Germany, Iran, Nigeria, and Brazil, at least three species of HM have been identified in horses, with a lack in knowledge in Latin American countries like Mexico. Our research aims to fill a crucial knowledge gap regarding the presence of HM...
Elmahallawy EK, Hassan MF, Cano-Terriza D, Albalawi NO, Fajardo T, Gouda AA, Atiba A, Hendawy A, Villena I, Barakat AM, Alzaylaee H, AlmerÃa S....Toxoplasmosis, caused by the intracellular protozoan (), continues to be a widespread parasitic zoonotic disease globally. The seroepidemiology of infection in Egyptian equids, particularly donkeys, remains insufficiently explored. The present study was designed to assess the seroprevalence of in equines from Northern Egypt. Unassigned: A total of 360 serum samples from two equine species (157 horses and 203 donkeys) were obtained during 2023. The Modified Agglutination Test (MAT, cut-off of 1:25) was used to screen for the anti- antibodies. The study also analyzed potential risk factors th...
Golen GS, ErganiÅŸ O, Balevi A. is an important bacterial pathogen and causes severe chronic granulomatous pneumonia in foals below 6 months of age. It has also become an opportunistic and emerging pathogen in immunocompromised humans. Vaccination is the most cost-effective strategy for controlling and preventing this infection. Although several potential virulence genes and candidate immunogens have been identified over the years, no effective vaccine is currently available to prevent disease in horses. Recently, bacterial vector vaccines have been shown to be promising for In this study, the gene of was cloned into P...
Hosseinzadeh S, Nofouzi K, Hasanzadeh F, Esmaeili S, Ayen E.Q fever is a frequently occurring illness that is induced by the bacterium ) that can infect humans and various animals. It targets the macrophage cells in the tissues, and circulating monocytes. Unassigned: This study was conducted between 2022 and 2023 in the West Azerbaijan and Ardabil provinces of northwestern Iran to examine the presence infection of . Specimens were obtained by swabbing from 140 mares (70 from each province) and 20 stallions (10 from each province) which were apparently healthy, and their DNA was analyzed using quantitative PCR assay detecting the element of the bacteri...
Hosseinzadeh S, Nofouzi K, Hasanzadeh F, Esmaeili S, Ayen E.Q fever is a frequently occurring illness that is induced by the bacterium ) that can infect humans and various animals. It targets the macrophage cells in the tissues, and circulating monocytes. Unassigned: This study was conducted between 2022 and 2023 in the West Azerbaijan and Ardabil provinces of northwestern Iran to examine the presence infection of . Specimens were obtained by swabbing from 140 mares (70 from each province) and 20 stallions (10 from each province) which were apparently healthy, and their DNA was analyzed using quantitative PCR assay detecting the element of the bacteri...
Cito F, Di Francesco CE, Averaimo D, Chiaverini A, Alessiani A, Di Domenico M, Cresci M, Rulli M, Cantelmi MC, Di Bernardo MD, Giammarino A.... subsp. (SEZ) is a major problem in equine veterinary medicine. Typically, a commensal in horses, SEZ can cause severe disease including respiratory infections, septicaemia and reproductive tract infections under certain conditions. Recent evidence suggests that humans can also develop severe disease infection through direct contact with infected animals or the consumption of contaminated unpasteurised milk and milk products. This study investigates SEZ strains isolated from nasal swabs of equidae in central Italy in 2023 to describe the epidemiology and genomic characteristics of circulating...
Thieulent CJ, Carossino M, Reis JKPD, Vissani MA, Barrandeguy ME, Valle-Casuso JC, Balasuriya UBR.Equine Infectious Anemia Virus (EIAV), the causative agent of Equine Infectious Anemia (EIA), presents a significant threat to equine populations worldwide. While local EIAV prevalence has been estimated in several studies, no global prevalence has been determined. Thus, this study aimed to review the literature on EIAV prevalence in the 21st century. A comprehensive electronic search was conducted in PubMed, Web of Science, Scopus, Google Scholar, SciELO.org, African Journals Online, and NZresearch.org, yielding 105 articles published between January 1st, 2000, and December 31st, 2024 (spanni...
Szacawa E, Kozieł N, Brzezińska S, Augustynowicz-Kopeć E, Weiner M, Szulowski K, Krajewska-Wędzina M. is one of the most dangerous pathogens of both animals and humans. Bovine tuberculosis (BTB) is a disease caused by mycobacteria belonging to the complex (MTBC), which spreads mainly among domestic cattle but also to mammals other than cattle. The transmission of MTBC between different species requires research and epidemiological investigations to control its spread. When multiple species are a reservoir of infection, it poses a significant public health and veterinary concern. In this study, the diagnosis of alpaca, cattle, horses, dogs, a sheep and a cat from one farm suspected of bovine ...
Pinho APVB, Ferreira F, Fuck JJ, de Oliveira JP, Dias RA, Grisi-Filho JHH, Heinemann MB, Telles EO, Amaku M, Ferreira Neto JS.Considering that control strategies for Equine Infectious Anemia, based on the serological diagnosis of equids and the removal of positive animals, may not be optimal for developing countries with an absolute predominance of grade working animals, this study aimed to address this issue based on the epidemiological situation of the disease in Pará, a state in the Brazilian Amazon. Pará was divided into five regions, and within each region a pre-established number of farms were randomly selected. Within each farm, a pre-set number of animals were randomly selected and submitted to Agar Gel Imm...
Mizani A, Taherkhani P, Kia Lashaki E, Hosseini SA, Basirpour B, Dodangeh S.Giardia duodenalis as a common zoonotic parasite is a public health problem infecting humans and a wide range of animals, including horses. This systematic review and meta-analysis was conducted to estimate the global pooled prevalence of Giardia infection in horses. Literature searches were conducted using databases including Scopus, ScienceDirect, PubMed, Web of Science and ProQuest to December 2023. A random-effect model was performed to calculate the pooled prevalence and corresponding 95% confidence interval (CI) according to the degree of heterogeneity in the included studies. Of 2661 ar...
Rajapakse S, Fernando N, Dreyfus A, Smith C, Rodrigo C.Leptospirosis is a zoonotic bacterial infection that is prevalent across all continents and is caused by pathogenic spirochaetes of the genus Leptospira. Although infection can be asymptomatic, symptomatic disease can vary in severity from mild to severe illness, the latter characterized by icterus and/or multi-organ dysfunction and potentially death. An estimated one million cases of leptospirosis occur globally each year, resulting in ~60,000 deaths. The pathogenesis of severe leptospirosis is poorly understood but is believed to involve an interplay between genetic predisposition, pathogen ...
Pádua GT, Tavares MA, de Lima NJ, Paula WVF, Dos Santos GC, Neves LC, Bittencourt RBM, Paludo RLDR, Cardoso ERN, da Silva BBF, Pádua BR....This study sought to investigate the presence of anti- spp. antibodies in georeferenced serum samples from equids across all regions of the state of Goiás, while also presenting variables that indicate risk factors for the circulation of rickettsiae, and evaluating the presence of rickettsial DNA in ticks collected from equids and the surrounding environment in the municipalities of Uruaçu and Porangatu, located in the northern region of the state. A total of 1156 equid serum samples provided by the Goiás Agricultural Defense Agency (Agrodefesa) were analyzed for antibodies against 4 antig...
Ji Y, Xu D, Si W, Zhang Y, Khan MZ, Zhao X, Liu W.The present study investigated the host cell response to EHV-8 infection in rabbit kidney (RK-13) cells through transcriptomic and proteomic approaches. At 24 h post-infection, a total of 2118 differentially expressed genes (DEGs) were identified, with 1338 upregulated and 780 downregulated. At 48 h, 7388 DEGs were detected, with 4342 upregulated and 3046 downregulated genes. Proteomic analysis revealed 932 differentially expressed proteins (DEPs) at 24 h (364 upregulated and 568 downregulated) and 3866 DEPs at 48 h (2285 upregulated and 1581 downregulated). Of these, 237 upregulated and 336 d...
James K, Chappell DE, Craig B, Pariseau C, Wright C, van Harreveld P, Barnum S, Pusterla N.The purpose of this study was to determine any associations of EHV-2, EHV-5, and dual infection with EHV-2/-5 with demographic parameters, clinical signs, and coinfection with other common respiratory pathogens. Nasal swabs collected from 9737 horses were tested for EHV-2 and EHV-5, as well as EHV-1, EHV-4, EIV, , ERAV, and ERBV, by qPCR. Clinical signs and demographic parameters were recorded, and prevalence factors were evaluated for significance regarding EHV-2 and/or EHV-5 infection. Out of the 9737 horses in this study, 17.8% tested EHV-2-positive ( = 1731), 15.8% tested EHV-5-positive ( ...
Furmanski M, Murcia PR.The ecological factors that led to the 1918 influenza pandemic remain unknown. We hypothesize that horses acted as intermediate hosts spreading a prepandemic avian-origin virus before 1918. This is supported by reports describing a large epizootic of unusually severe equine influenza beginning in 1915. Furthermore, the high horse demand during World War I resulted in one of the biggest equine mobilizations in North America between 1914 and 1918. This extensive movement of horses provided abundant opportunities for virus reassortment between prepandemic avian and human influenza viruses. Archiv...
Khaing Y, Htun LL, Linn KS, Kyaw WO, Nwae TT, Chel HM, Win SY, Murata S, Nakao R, Nonaka N, Bawm S.The study aimed to determine the prevalence of blood parasites in horses and identify risk factors and molecular detection of piroplasm species (Theileria equi and Babesia caballi) of horses in Myanmar. Blood samples (n = 302) were collected from five regions of Myanmar. Blood smears were screened for presence of piroplasms. Samples positive for piroplasms were subjected to molecular identification using primers specific to the small subunit ribosomal RNA (SSU rRNA) of piroplasms. The overall prevalence of blood parasites (piroplasms, Trypanosoma spp., and microfilaria of Setaria equina) w...
Kamutzki CJ, Emmerich IU.In 2024, there was no release of a novel pharmaceutical agent for horses and food-producing animals or an extension of existing active ingredients to other animal species on the German veterinary medicinal products market. Formic acid is now available for a new form of treatment, the short-term treatment of honeybees, and clenbuterol is available in a new dosage form, as an oral solution for horses. In the field of immunological veterinary medicinal products, three new vaccines were launched on the German veterinary medicinal products market. For the first time, a vaccine against in cattle, a...
Gao X, Liu J, Xu K, Hu J, Xiao C, Wang D, Li C, Ji C, Yao X, Wang PG, Jing Y, He Y, Shen CK.Typically, the antigen-specific antibodies constitute a small fraction-often estimated to be around 2-10Â %-of the total IgG in the serum after immunization. This low percentage necessitates the use of purification techniques to enrich the antigen-specific antibodies for therapeutic or research purposes. This study introduces an affinity chromatography column using NHS-activated Sepharose as a matrix and the tetanus toxin subunit C, TeNT-Hc-C869A, as a ligand, enabling the purification of polyclonal antibodies with high specificity. This process improves antitoxin purity to over 95Â %, effecti...
Nielsen MK, Bartholdy ID, Kristensen KS, Borrye JC, Meilvang KSS, Rendtorff CEK, Hjortflod MD, Fuglbjerg V, Karlsson M, Petersen HH, Toft K....Equine strongylids are ubiquitous and can cause severe health issues. Anthelmintic resistance is widely common in cyathostomin parasites, and recent studies have documented increasing incidence of resistance to the macrocyclic lactone drug class. Several European countries have implemented prescription-only restrictions of anthelmintic usage by law to reduce anthelmintic treatment intensity and decrease the selection pressure for drug resistance. However, long term outcomes of this approach have not been thoroughly evaluated. The aim was to determine ivermectin efficacy in strongylids by means...
Kukhar Y, Bailina G, Smagulova A, Uakhit R, Kiyan V.Equine skin mycoses are a significant concern in Kazakhstan's livestock industry due to the country's historical livestock farming practices, the development of equestrian sports, and food traditions. Skin infections are among the most common fungal infections in horses. Emerging pathogens of equine dermatophytosis include keratinophilic Chrysosporium spp., which can degrade and metabolize keratin found in superficial tissues. This, combined with their thermotolerance, contributes to their pathogenicity. In this study, we investigated the biological properties and pathogenicity of two Chrysosp...
Keven JB, Walker ED.Eastern equine encephalomyelitis virus (EEEV) is endemic in Michigan, showing an upsurge in human cases and in infections of white-tailed deer, horses, and other animals in the past decade (2010-2020). However, blood-host associations of the enzootic mosquito vector Culiseta melanura in the Great Lakes region are poorly known compared with other better-studied regions. Vertebrate sources of blood meals of Cs. melanura collected from resting boxes were determined through sequencing of the mitochondrial cytochrome B gene generated from polymerase chain reaction. Thirty-six unique avian species w...
Polo MC, Huby FD, Uehlinger FD, Rubin JE.Antimicrobial resistance is a serious threat in human and veterinary medicine. Among the most problematic resistant organisms are the extended-spectrum β-lactamase (ESBL)-producing Enterobacterales, which are resistant to the 3rd-generation cephalosporins. The purpose of this study was to determine the frequency of colonization of horses admitted to the Western College of Veterinary Medicine with resistant Escherichia coli. Unassigned: Rectal swabs were collected from 60 horses admitted between November 2021 and March 2022. Swabs were selectively cultured for E. coli, which was identified usi...
Lyons S, Kapoor A, Sharp C, Schneider BS, Wolfe ND, Culshaw G, Corcoran B, McGorum BC, Simmonds P.Although the origin of hepatitis C virus infections in humans remains undetermined, a close homolog of this virus, termed canine hepacivirus (CHV) and found in respiratory secretions of dogs, provides evidence for a wider distribution of hepaciviruses in mammals. We determined frequencies of active infection among dogs and other mammals in the United Kingdom. Samples from dogs (46 respiratory, 99 plasma, 45 autopsy samples) were CHV negative by PCR. Screening of 362 samples from cats, horses, donkeys, rodents, and pigs identified 3 (2%) positive samples from 142 horses. These samples were gene...
Giguère S, Cohen ND, Chaffin MK, Slovis NM, Hondalus MK, Hines SA, Prescott JF.Rhodococcus equi, a gram-positive facultative intracellular pathogen, is one of the most common causes of pneumonia in foals. Although R. equi can be cultured from the environment of virtually all horse farms, the clinical disease in foals is endemic at some farms, sporadic at others, and unrecognized at many. On farms where the disease is endemic, costs associated with morbidity and mortality attributable to R. equi may be very high. The purpose of this consensus statement is to provide recommendations regarding the diagnosis, treatment, control, and prevention of infections caused by R. equi...
Lobsiger L, Müller N, Schweizer T, Frey CF, Wiederkehr D, Zumkehr B, Gottstein B.The present case report describes a novel etiological agent of cutaneous leishmaniasis that appears for the first time in a cow. A similar agent had recently been described as causing autochthonous infections in horses of Germany and Switzerland. The infection in the cow was initially diagnosed upon clinical and immunohistological findings. Subsequent comparative sequence analysis of diagnostic PCR products from the internal transcribed spacer 1 (ITS1) of ssrRNA classified the respective isolate as neither Old World nor New World Leishmania species, but yielded complete identity of the analyse...
Horta MC, Labruna MB, Pinter A, Linardi PM, Schumaker TT.This study investigated rickettsial infection in animals, humans, ticks, and fleas collected in five areas of the state of São Paulo. Eight flea species (Adoratopsylla antiquorum antiquorum, Ctenocephalides felis felis, Polygenis atopus, Polygenis rimatus, Polygenis roberti roberti, Polygenis tripus, Rhopalopsyllus lugubris, and Rhopalopsyllus lutzi lutzi), and five tick species (Amblyomma aureolatum, Amblyomma cajennense, Amblyomma dubitatum, Ixodes loricatus, and Rhipicephalus sanguineus) were collected from dogs, cats, and opossums. Rickettsia felis was the only rickettsia found infecting ...
Jongejan F, Ringenier M, Putting M, Berger L, Burgers S, Kortekaas R, Lenssen J, van Roessel M, Wijnveld M, Madder M.Autochthonous populations of Dermacentor reticulatus ticks in the Netherlands were discovered after fatal cases of babesiosis occurred in resident dogs in 2004. The presence of D. reticulatus in the Netherlands has also linked with the emergence of piroplasmosis in the resident horse population. The aim of this study was to put together results of continued surveillance of field sites and hosts for this tick in the Netherlands and also in Belgium and determine their infection status for Babesia and Theileria species. Methods: Ticks were collected from the vegetation at 11 locations between 201...
von Bargen K, Haas A.The soil actinomycete Rhodococcus equi is a pulmonary pathogen of young horses and AIDS patients. As a facultative intracellular bacterium, R. equi survives and multiplies in macrophages and establishes its specific niche inside the host cell. Recent research into chromosomal virulence factors and into the role of virulence plasmids in infection and host tropism has presented novel aspects of R. equi infection biology and pathogenicity. This review will focus on new findings in R. equi biology, the trafficking of R. equi-containing vacuoles inside host cells, factors involved in virulence and ...
Morgan M.Methicillin-resistant Staphylococcus aureus (MRSA) is increasing worldwide. Occasionally, animals are colonized or infected incidentally with human strains. Recently, however, new strains of MRSA emerging from within the animal kingdom, particularly in pigs, are causing human infection. MRSA has been reported in species as diverse as companion animals, horses and pigs, through to chinchillas, bats and parrots. In contrast, whereas strains of community-associated MRSA, the majority of which carry genes encoding Panton-Valentine leucocidin, are spreading rapidly in human populations, only sporad...
Cantile C, Di Guardo G, Eleni C, Arispici M.West Nile (WN) virus infection is a mosquito-borne flavivirosis endemic in Africa and Asia. Clinical disease is usually rare and mild and only in a few cases the infection causes encephalomyelitis in horses, fever and meningoencephalitis in man. We report here the clinical and pathological findings in an epidemic of the disease involving 14 horses from Tuscany, Italy. All cases were observed from August to October 1998. Affected horses showed ataxia, weakness paresis of the hindlimbs and, in 6 cases, there was paraparesis progressing to tetraplegia and recumbency within 2 to 9 days. Eight anim...
Bhoora R, Franssen L, Oosthuizen MC, Guthrie AJ, Zweygarth E, Penzhorn BL, Jongejan F, Collins NE.A molecular epidemiological survey of the protozoal parasites that cause equine piroplasmosis was conducted using samples collected from horses and zebra from different geographical locations in South Africa. A total of 488 samples were tested for the presence of Theileria equi and/or Babesia caballi using the reverse line blot hybridization assay. Ten percent of the samples hybridized to the Theileria/Babesia genus-specific probe and not to the B. caballi or T. equi species-specific probes, suggesting the presence of a novel species or genotype. The small subunit of rRNA gene (18S; approximat...
Hassan HK, Cupp EW, Hill GE, Katholi CR, Klingler K, Unnasch TR.An important variable in the amplification and escape from the enzootic cycle of the arboviral encephalitides is the degree of contact between avian hosts and mosquito vectors. To analyze this interaction in detail, blood-fed mosquitoes that were confirmed vectors of eastern equine encephalomyelitis (EEE) virus were collected in 2002 from an enzootic site in central Alabama during the time this virus was actively transmitted. Avian-derived blood meals were identified to the species level of the host, and the proportion derived from each species was compared with the overall composition of the ...
Malkinson M, Banet C.Surveys on wild birds conducted during the last two decades in Europe, notably Poland and the Czech Republic, to determine their infection rate with WN virus have revealed endemic foci of infection. Some species of seropositive birds were nonmigrators while others were hatchlings of migrating species. Persistently infected avian reservoirs are potential sources of viruses for mosquitoes that multiply in the temperate European zone in hot, wet summers. In the past, evidence for geographical circulation of WN viruses was based on antigenic analysis of strains from different countries while more ...
van der Kolk JH, Endimiani A, Graubner C, Gerber V, Perreten V.Acinetobacter spp. are aerobic, rod-shaped, Gram-negative bacteria belonging to the Moraxellaceae family of the class Gammaproteobacteria and are considered ubiquitous organisms. Among them, Acinetobacter baumannii is the most clinically significant species with an extraordinary ability to accumulate antimicrobial resistance and to survive in the hospital environment. Recent reports indicate that A. baumannii has also evolved into a veterinary nosocomial pathogen. Although Acinetobacter spp. can be identified to species level using matrix-assisted laser desorption/ionisation time-of-flight mas...
Brault AC, Powers AM, Chavez CL, Lopez RN, Cachón MF, Gutierrez LF, Kang W, Tesh RB, Shope RE, Weaver SC.Eastern equine encephalitis virus (EEEV), the sole species in the EEE antigenic complex, is divided into North and South American antigenic varieties based on hemagglutination inhibition tests. Here we describe serologic and phylogenetic analyses of representatives of these varieties, spanning the entire temporal and geographic range available. Nucleotide sequencing and phylogenetic analyses revealed additional genetic diversity within the South American variety; 3 major South/Central American lineages were identified including one represented by a single isolate from eastern Brazil, and 2 lin...
Oladunni FS, Horohov DW, Chambers TM.Equine herpesvirus-1 (EHV-1) is one of the most important and prevalent viral pathogens of horses and a major threat to the equine industry throughout most of the world. EHV-1 primarily causes respiratory disease but viral spread to distant organs enables the development of more severe sequelae; abortion and neurologic disease. The virus can also undergo latency during which viral genes are minimally expressed, and reactivate to produce lytic infection at any time. Recently, there has been a trend of increasing numbers of outbreaks of a devastating form of EHV-1, equine herpesviral myeloenceph...
Richter PJ, Kimsey RB, Madigan JE, Barlough JE, Dumler JS, Brooks DL.Ehrlichia equi, a rickettsia described from horses in California 30 yr ago, causes equine granulocytic ehrlichiosis throughout the Americas and possibly Europe. Here, we report experimental transmission of E. equi from infected to susceptible horses through bites of western blacklegged ticks, Ixodes pacificus (Cooley & Kohls). In preliminary field studies, only I. pacificus consistently infested horses and vegetation at 3 locations with contemporary cases of equine ehrlichosis, and in particular, I. pacificus was the only species found attached to all of the infected horses. Exposure to bites ...
Munderloh UG, Madigan JE, Dumler JS, Goodman JL, Hayes SF, Barlough JE, Nelson CM, Kurtti TJ.The equine granulocytic ehrlichiosis agent, Ehrlichia equi, is closely related or identical to the human granulocytic ehrlichiosis (HGE) agent. Both are suspected of being transmitted by ticks. We have successfully isolated E. equi in a cell line, IDE8, derived from a putative vector, the tick Ixodes scapularis. Peripheral blood leukocytes from an experimentally infected horse were inoculated onto IDE8 monolayers. Cultures were incubated in a candle jar at 34 degrees C in tick cell culture medium with NaHCO3 and an organic buffer [3-(N-morpholino)-propanesulfonic acid] (MOPS). Within 2 weeks, ...
Kapoor A, Simmonds P, Cullen JM, Scheel TK, Medina JL, Giannitti F, Nishiuchi E, Brock KV, Burbelo PD, Rice CM, Lipkin WI.The recent identification of nonprimate hepaciviruses in dogs and then in horses prompted us to look for pegiviruses (GB virus-like viruses) in these species. Although none were detected in canines, we found widespread natural infection of horses by a novel pegivirus. Unique genomic features and phylogenetic analyses confirmed that the tentatively named equine pegivirus (EPgV) represents a novel species within the Pegivirus genus. We also determined that EPgV causes persistent viremia whereas its clinical significance is undetermined.
Cullinane A, Newton JR.To date, equine influenza outbreaks have been reported all over the world with the exception of a small number of island nations including New Zealand and Iceland. Influenza is endemic in Europe and North America and is considered to be of potentially major economic significance to the equine industry worldwide. The importation of subclinically infected vaccinated horses, and inadequate quarantine procedures have resulted in several major outbreaks in susceptible populations for example, in Australia (2007) when more than 76,000 horses on over 10,000 properties were reported as infected. This ...
Alhassan A, Pumidonming W, Okamura M, Hirata H, Battsetseg B, Fujisaki K, Yokoyama N, Igarashi I.With the aim of developing more simple diagnostic alternatives, a differential single-round and multiplex polymerase chain reaction (PCR) method was designed for the simultaneous detection of Babesia caballi and Babesia equi, by targeting 18S ribosomal RNA genes. The multiplex PCR amplified DNA fragments of 540 and 392 bp from B. caballi and B. equi, respectively, in one reaction. The PCR method evaluated on 39 blood samples collected from domestic horses in Mongolia yielded similar results to those obtained from confirmative PCR methods that had been established earlier. Thus, the single-roun...
Bartsch S, Bauer B, Wiemann A, Clausen PH, Steuber S.Host feeding patterns of engorged sibling species of the Culicoides obsoletus and Culicoides pulicaris groups captured during three nights on two selected farms maintaining either cattle, sheep, horses, and pigs (Seedorf, Brandenburg) or cattle, sheep, moufflons, and red and fallow deer (Paulinenaue, Brandenburg) were determined by polymerase chain reaction amplification using conserved primers and sets of species-specific primers derived from vertebrates mitochondrial cytochrome b. Out of a total of 177 blood meals analysed, 115 (65%) tested positive for a blood meal from vertebrates. 63.5% (...
von Samson-Himmelstjerna G, Fritzen B, Demeler J, Schürmann S, Rohn K, Schnieder T, Epe C.In 2003 and 2004, on a total of 63 different German horse farms, a survey using the faecal egg count reduction (FECR) test was performed to investigate the efficacy of ivermectin (IVM, Ivomec) and pyrantel (PYR, Banminth) treatment against gastro-intestinal nematodes in a total of 767 horses. IVM treatment resulted in 100% reduction of the cyathostomin egg production 14 and 21 days post-treatment (d.p.t.) on 37 farms. On the remaining five farms, the mean faecal egg count reduction ranged between 97.7 and 99.9%. The mean cyathostomin FECR following PYR treatment ranged between 92.2 and 100% on...
Takai S, Koike K, Ohbushi S, Izumi C, Tsubaki S.Antigens of Rhodococcus equi were analyzed by immunoblotting with naturally infected foal sera. Immunoblots of whole-cell antigen preparations of clinical isolates of R. equi revealed that major protein bands with molecular masses of 15 to 17 kDa were present in all clinical isolates tested and all isolates virulent for mice. In contrast, the 15- to 17-kDa antigens were not identified by immunoblotting in ATCC 6939, a type strain of R. equi that was avirulent for mice. Whole-cell antigens of 102 environmental isolates were investigated by immunoblotting and the mouse pathogenicity test. Twenty...
Field HE.Hendra virus causes acute and highly fatal infection in horses and humans. Pteropid bats (flying-foxes) are the natural host of the virus, with age and species being risk factors for infection. Urine is the primary route of excretion in flying-foxes, with viral RNA more frequently detected in Pteropus alecto and P. conspicillatus than other species. Infection prevalence in flying-foxes can vary between and within years, with a winter peak of excretion occurring in some regions. Vertical transmission and recrudescing infection has been reported in flying-foxes, but horizontal transmission is ev...
Rushlow K, Olsen K, Stiegler G, Payne SL, Montelaro RC, Issel CJ.The nucleotide sequence of the envelope (env) gene region of equine infectious anemia virus (EIAV), a member of the lentivirus subfamily of retroviruses, has been determined from a clone of integrated proviral DNA for which the gag and pol sequences have been reported previously. The env gene is 859 codons in length and the sequence reported here is consistent with the published biochemical properties of EIAV glycoproteins. The env gene region of EIAV shares considerable structural similarities but negligible sequence homologies with the env genes of other members of the lentivirus subfamily, ...
Divers TJ, Tennant BC, Kumar A, McDonough S, Cullen J, Bhuva N, Jain K, Chauhan LS, Scheel TKH, Lipkin WI, Laverack M, Trivedi S, Srinivasa S....Equine serum hepatitis (i.e., Theiler's disease) is a serious and often life-threatening disease of unknown etiology that affects horses. A horse in Nebraska, USA, with serum hepatitis died 65 days after treatment with equine-origin tetanus antitoxin. We identified an unknown parvovirus in serum and liver of the dead horse and in the administered antitoxin. The equine parvovirus-hepatitis (EqPV-H) shares <50% protein identity with its phylogenetic relatives of the genus Copiparvovirus. Next, we experimentally infected 2 horses using a tetanus antitoxin contaminated with EqPV-H. Viremia develop...
Morens DM, Taubenberger JK.To understand human influenza in a historical context of viral circulation in avian species, mammals, and in the environment. Methods: Historical review. Methods: Global events in a variety of circumstances over more than 3,000 years time. Methods: Comprehensive review of the historical literature including all major publications on pandemic and panzootic influenza. Methods: Influenza pandemics, panzootics, major epidemics and epizootics, and instances of interspecies transmission of influenza A. Results: Extensive documentation of human and animal influenza over many centuries suggests that i...
Nara PL, Garrity RR, Goudsmit J.The production of immunoglobulin capable of neutralizing the infectivity of a virus represents one of the most remarkable molecular accomplishments of the host's available immune defenses. It should be no surprise that a virus that has existed in the parenchyma of the immune system has evolved as an equally dynamic molecule (i.e., viral envelope) for survival. Neutralizing immunoglobulin (Ig) can best serve the host under conditions where the invading pathogen requires a well-defined cell-free state for establishing an infection or transmission. Evidence for a controlling and therefore protect...
Cuny C, Strommenger B, Witte W, Stanek C.During 2006 and 2007 small clusters of methicillin-resistant Staphylococcus aureus (MRSA) infections in horses were recorded in different clinical departments of a veterinary university. The infections were caused by different MRSA clones (ST1, ST254, and ST398). In the same time, nasal colonization of veterinarians, veterinary personnel, and students was observed indicating transmission to humans.
