Infections in horses encompass a range of diseases caused by various pathogens, including bacteria, viruses, fungi, and parasites. These infections can affect different systems within the horse, such as the respiratory, gastrointestinal, and integumentary systems, leading to a variety of clinical signs depending on the pathogen and the severity of the infection. Common infectious diseases in horses include equine influenza, strangles, and equine herpesvirus. Diagnosis often involves clinical examination, laboratory testing, and sometimes imaging, to identify the causative agent and assess the extent of the disease. Treatment strategies may include antimicrobial therapy, supportive care, and preventive measures such as vaccination and biosecurity practices. This page aggregates peer-reviewed research studies and scholarly articles that explore the pathogenesis, diagnosis, treatment, and prevention of infectious diseases in equine populations.
Leus EK, Collins N, Gruyaert M, Kennedy RN, McConnell E, McGorum BC, Luethy D, Sanz M, Versporten A, Viljoen A, Lyle CH.Antimicrobial resistance (AMR) is increasingly recognised in equine medicine. Antimicrobial use (AMU) is a key driver of AMR. Objective: To pilot a point prevalence survey (PPS), based on the Global-PPS used in human hospitals, to obtain data on antibiotic prescribing and AMR in equine hospitals and to identify targets for improvement in AMU. Methods: Point prevalence survey. Methods: Eight equine hospitals located in Australia, Belgium, South Africa, the United Kingdom and the United States were recruited. Data on AMU were collected from all in-patients on antibiotic treatment at 08h00 on fou...
Nikvand AA, Jalali SM, Bahrami S, Rahij Torfi H.Trypanosoma evansi (T. evansi) is a hemoprotozoan parasite affecting camels and equids, such as horses, mules, and donkeys, and is known to cause surra disease in these animals. Despite the worldwide distribution of T. evansi infections in equids, surra has not been reported in Arabian horses in Khuzestan Province for over 60 years. In September 2018, a 7-year-old Arabian mare was referred from a 10-horse farm in the suburbs of Ahvaz City. The mare presented with a history of weight loss, poor appetite, and proximity to a camel herd. Physical examination revealed a poor body condition score ...
Turcotte GK, O'Sullivan TL, Spence KL, Winder CB, Greer AL.Horses may travel for a variety of reasons, leading to potential exposure to pathogens. Typically, these movements are bidirectional with horses returning to their home facility, therefore also risking pathogen exposure to resident horses at home facilities. The Canadian National Farm and Facility Level Biosecurity Standard for the Equine Sector was designed to outline best practices for managing biosecurity at equestrian facilities, however, there is a gap between the implementation of these recommendations and the day-to-day operations of equestrian facilities. This study aimed to explore th...
Abbas I, Ahmed F, Muqaddas H, Alberti A, Varcasia A, Sedda L.Climate change can cause spatio-temporal shifts in the epidemiology of various vector borne pathogens, especially in vulnerable areas such as the Mediterranean Basin (MB). Among these pathogens, the West Nile virus (WNV) became endemic in the region. This systematic review and meta-analysis study summarizes WNV epidemiology, molecular characteristics, and surveillance in various MB countries, relying on data and scientific articles on WNV published during 2010-2023. The number of published articles varied across the three MB subregions: Southern Europe (n = 153), North Africa (n = 33), and...
Kutumbetov L, Myrzakhmetova B, Tussipova A, Zhapparova G, Tlenchiyeva T, Bissenbayeva K, Nurabayev S, Kerimbayev A.Equine rhinopneumonia, caused by equine herpesvirus types 1 and 4 (EHV-1 and EHV-4), continues to be a significant health and economic concern in the global equine industry, particularly in Kazakhstan. While vaccines targeting EHV-1 are available, there is currently no licensed monovalent vaccine for EHV-4, and existing formulations offer limited protection against this serotype. This study aimed to develop and evaluate a freeze-dried, live-attenuated EHV-4 vaccine with improved safety, stability, and immunogenicity. Methods: A field isolate of EHV-4 was attenuated through serial passaging in ...
Al-Rammahi HM, Mohsen RK, Othman RM.West Nile virus (WNV) circulates between birds and mosquitoes, with horses and humans as incidental dead-end hosts. Despite documented cases in neighboring countries and human cases in southern Iraq, no previous studies have investigated WNV in Iraqi horses. Unassigned: To determine the seroprevalence of WNV in horses from three southern Iraqi governorates (Thi-Qar, Misan, and Basrah) between March and June 2024. Unassigned: Blood samples were collected from 236 horses regardless of age, sex, or health status. Serum samples were analyzed using commercial competitive enzyme-linked immunosorbent...
Granella MCS, Mendes RP, da Silva Casa M, Ribeiro GSN, Sangioni LA, Vogel FSF, Braünig P, Ferian PE, Salbego FZ, Schwarz DGG, Fonteque JH.Protozoan Neospora spp. is known to negatively affect horses reared in rural and urban environments, being studied for causing abortion, neonatal mortality and central nervous system disorders in horses. This study aimed to verify the occurrence of anti-Neospora spp. antibodies in horses bred in rural and urban areas from southern Brazil and the risk factors associated with infection. The study consisted of 400 horses, which 241 were bred in rural areas and 159 in urban areas. The detection of serum anti-Neospora spp. antibodies was determined using Immunofluorescence Antibody Test (IFAT). The...
Ochigbo GO, Ahn S, Belhumeur KA, Poissant J, Rosa BV.Unmanaged feral horses, naïve to dewormers, offer a unique opportunity to study natural communities of equine parasites. These communities may include parasites that are rare in managed populations, and these may be transmitted to domestic horses in areas where there is contact between feral and domestic equine populations. There have been only a few studies of gastrointestinal parasite populations in horses, and very few from North American equine populations. This study aimed to gain insights into parasite biology through identification of the strongyle parasite species infecting feral hors...
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 ...
Forni G, Ellero N, Mannini A, Scacco L, Freccero F.A 3-year-old Quarter Horse stallion was referred for headshaking (HS) syndrome of one month duration. The horse underwent complete HS workup. Physical examination revealed up-and-down head movements associated with nose snorting during lunging and riding, in the absence of other abnormalities at rest or in motion. Lameness, neurologic and behavioural evaluations were unremarkable. Endoscopic examination of the upper respiratory tract showed bilateral guttural pouches (GPs) inflammation. The mucosal surface was altered by the presence of areas of microbullous appearance coalescing into some bul...
Mrzdovnik N, Babič J, Lužnik D, Žigon D, Mrzdovnik M, Tavčar-Kalcher G, Tomič V, Prescott JF, Vengust M.Several bacteria associated with chronic lung pathology use quorum sensing (QS) signaling molecules to regulate their virulence in pure cultures and poly-microbial communities. Their excessive growth and biofilm formation in the respiratory tract increase the morbidity and mortality of inflammatory airway diseases in humans, such as chronic obstructive pulmonary disease (COPD), asthma and cystic fibrosis (CF). In horses, severe equine asthma (SEA) has many parallels to these human diseases. We hypothesized that QS molecules associated with the most common biofilm-forming lung pathogens in huma...
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...
Bordoni T, Dini FM, Morini M, Rinnovati R, Spadari A, Galuppi R.Mycetoma is a fungal chronic skin proliferative lesion rarely encountered in horses and often associated with fungi such as Scedosporium spp., Madurella spp., Phialophora spp., Curvularia spp., and less frequently with Aspergillus spp. A case of subcutaneous mycetoma in the cervical region in a 7-year-old male Quarter Horse, diagnosed through cytological, histological, cultural and molecular methods, is reported. Aspergillus nidulans, usually implicated in guttural pouch mycosis, was identified. This unusual case represents the second case report of mycetoma caused by Aspergillus nidulans in t...
Lin H, Deng D, Yan Z, Zou G, Shen Y.Staphylococcus aureus can transfer from animals to humans. Lichuan horse is an isolated breed living in a high-altitude area with limited use of antibiotics and is bred for use in tourism. To evaluate the risk of human-animal cross-transmission, the S. aureus was isolated from three horse farms in Lichuan, including healthy horses and horses with skin infections, farm workers and environment. From a collection of 111 samples, 18 S. aureus isolates were obtained. All the isolates were genome sequenced and their biological characteristics including antimicrobial susceptibility, virulence and bi...
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 =...
Duaso J, Perez-Ecija A, Martínez 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, Martínez-Hernández JM, Aguilar-Domínguez 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...
Franco JJ, Gonzálvez M, Cano-Terriza D, Barbero-Moyano J, Jose-Cunilleras E, Alguacil E, García J, García-Bocanegra I.Equine viral arteritis is a notifiable infectious disease with sanitary and economic implications at a global scale. A cross-sectional serosurvey was performed to determine the exposure of equids to the Alphaarterivirus equid [Equine Arteritis Virus (EAV)] in three regions in western Europe. Serum samples from 1425 equids (1196 horses, 104 donkeys, and 125 mules/hinnies) from Catalonia (northeastern Spain), Andalusia (southern Spain) and southeastern United Kingdom (UK) were collected during the period 2011-2023. The overall EAV seroprevalence in EAV-unvaccinated equids was 9.7 % (138/1425; 9...
Elmahallawy EK, Hassan MF, Cano-Terriza D, Albalawi NO, Fajardo T, Gouda AA, Atiba A, Hendawy A, Villena I, Barakat AM, Alzaylaee H, Almería 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, Erganiş 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...
Wright JP, Gray SM, Bishop RC.To describe and demonstrate the collection of abdominal fluid from a standing, sedated equine patient. Unassigned: 1 healthy university-owned animal was used for abdominocentesis demonstration. Images from various clinical cases from the University of Illinois Veterinary Teaching Hospital are shown. Unassigned: Under standing sedation, a 10 X 10-cm area is clipped and aseptically prepared on the most dependent portion of the abdomen to the right of midline. One to 2 mL of 2% lidocaine is instilled subcutaneously and into the abdominal musculature at the abdominocentesis site. A stab incision i...
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...
Serpa PBS, Bogers S, Byron C, Cardona G, Patton M.A 1-year-old American Quarter horse was presented with acute onset of right hind lameness. On physical examination, there was synovial effusion of the right tarsocrural joint. Synovial fluid cytology revealed a marked eosinophilic synovitis. Serology indicated evidence of acute and chronic infection with Borrelia burgdorferi, although PCR of the synovial fluid was negative. The filly was treated with phenylbutazone and oxytetracycline, and repeated synovial cytology indicated improvement. The filly was discharged with a prescription of minocycline for 30 days. Despite initial improvement, recu...
Issel CJ, Horohov DW, Lea DF, Adams WV, Hagius SD, McManus JM, Allison AC, Montelaro RC.We report here on a series of vaccine trials to evaluate the effectiveness of an inactivated equine infectious anemia virus (EIAV) whole-virus vaccine and of a subunit vaccine enriched in EIAV envelope glycoproteins. The inactivated vaccine protected 14 of 15 immunized ponies from infection after challenge with at least 10(5) 50% tissue culture-infective doses of the homologous prototype strain of EIAV. In contrast, it failed to prevent infection in any of 15 immunized ponies that were challenged with the heterologous PV strain. Levels of PV virus replication and the development of disease, ho...
O'Rourke K, Perryman LE, McGuire TC.Equine infectious anaemia virus is related by genome sequence homology to human immunodeficiency virus, caprine arthritis-encephalitis virus and visna virus. Failure of the host to mount a strong neutralizing response detectable in vitro or to eliminate persistent infection in vivo characterizes lentivirus infections in the natural host. In this study the specificities and neutralizing activity of antibodies induced during experimental infection with equine infectious anaemia virus were investigated using antiviral ELISA, radioimmunoprecipitation and neutralization assays. ELISA antibody titre...
Guardabassi L, Apley M, Olsen JE, Toutain PL, Weese S.Optimization of antimicrobial treatment is a cornerstone in the fight against antimicrobial resistance. Various national and international authorities and professional veterinary and farming associations have released generic guidelines on prudent antimicrobial use in animals. However, these generic guidelines need to be translated into a set of animal species- and disease-specific practice recommendations. This article focuses on prevention of antimicrobial resistance and its complex relationship with treatment efficacy, highlighting key situations where the current antimicrobial drug product...
Kappmeyer LS, Perryman LE, Hines SA, Baszler TV, Katz JB, Hennager SG, Knowles DP.A competitive-inhibition enzyme-linked immunosorbent assay (cELISA) was developed for detection of equine antibodies specific for Babesia caballi. The assay used recombinant B. caballi rhoptry-associated protein 1 (RAP-1) and monoclonal antibody (MAb) 79/17.18.5, which is reactive with a peptide epitope of a native 60-kDa B. caballi antigen. The gene encoding the recombinant antigen was sequenced, and database analysis revealed that the gene product is a rhoptry-associated protein. Cloning and expression of a truncated copy of the gene demonstrated that MAb 79/17.18.5 reacts with the C-termina...
Cormier A, Zhang PLC, Chalmers G, Weese JS, Deckert A, Mulvey M, McAllister T, Boerlin P.Historically, extended-spectrum cephalosporin resistance in bacteria from animals in Canada has been attributed to the SHV and CMY β-lactamase families. This pattern is beginning to change with the emergence of the bla gene family among Escherichia coli recovered from various animal species. Here we analyze and compare whole genome sequences of bla-positive E. coli isolates (n = 173) from dogs, chicken, swine, horses and beef cattle in Canada. Ten bla variants were identified with bla and bla being identified in most animal species. These variants occurred across many sequence types, sugg...
Hillidge CJ.The selection of lipid-soluble antibiotics capable of intracellular penetration is considered critical for the successful treatment of Rhodococcus equi pneumonia and lung abscesses in foals. Two such antibiotics: erythromycin (25 mg kg-1, three times daily) and rifampin (5 mg kg-1 twice daily) have been used in combination for this purpose at the University of Florida since 1981. Positive evidence of R. equi was present on culture of tracheal aspirates in 57 foals, most of which exhibited radiographic evidence of extensive lung abscessation. The duration of therapy ranged from 4 to 9 weeks. Mi...
Schneider RK, Bramlage LR, Moore RM, Mecklenburg LM, Kohn CW, Gabel AA.The medical records of 192 horses with septic arthritis/tenosynovitis 1979-1989 were reviewed. Forty-three horses developed infection after an intra-articular injection, 46 following a penetrating wound, 25 following surgery, 66 were foals less than 6 months old, and 12 were adult horses without a known aetiology. Haematogenous infection of a joint occurs in adult horses and should be considered as a differential diagnosis in horses with an acute onset of severe lameness. The aetiology of the infection had a significant effect on the type of bacteria identified by culture. Staphylococcus was c...
Boerlin P, Eugster S, Gaschen F, Straub R, Schawalder P.Acinetobacter baumannii, Enterococcus faecalis, Enterococcus faecium, and Staphylococcus intermedius isolates from infected surgical wounds and other types of infections in a veterinary teaching hospital were typed by pulsed field gel electrophoresis. A first cluster of infections with a multiresistant A. baumannii strain was observed in dogs and cats in 1998-1999. This strain disappeared after cleaning and disinfection of the companion animals intensive care unit. It was followed in 2000 by a second multiresistant strain, which caused another cluster of infections and was also transmitted to ...
Kydd JH, Townsend HG, Hannant D.Equine herpesvirus-1 (EHV-1) is an alphaherpesvirus which infects horses, causing respiratory and neurological disease and abortion in pregnant mares. Latency is established in trigeminal ganglia and lymphocytes. Immunity to EHV-1 lasts between 3 and 6 months. Current vaccines, many of which contain inactivated virus, have reduced the incidence of abortion storms in pregnant mares but individual animals, which may be of high commercial value, remain susceptible to infection. The development of effective vaccines which stimulate both humoral and cellular immune responses remains a priority. Uti...
Laus F, Veronesi F, Passamonti F, Paggi E, Cerquetella M, Hyatt D, Tesei B, Fioretti DP.In order to investigate the prevalence of tick-borne diseases, equine piroplasmosis, equine granulocytic anaplasmosis and Lyme borreliosis in Central Italy, blood samples from 300 horses were analyzed for the presence of antibodies against Babesia caballi, Theileria equi, Anaplasma phagocytophilum and Borrelia burgdorferi using the IFAT. The blood samples were also subjected to PCR assays in order to detect pathogen DNA. A total of 78 (26.0%) and 123 (41.0%) horses were found to be seropositive for B. caballi and T. equi, respectively, while 41 (13. 4%) and 21 (7.0%) horses were, respectively,...
Donadieu E, Bahuon C, Lowenski S, Zientara S, Coulpier M, Lecollinet S.West Nile virus (WNV) is a neurotropic flavivirus that cycles between mosquitoes and birds but that can also infect humans, horses, and other vertebrate animals. In most humans, WNV infection remains subclinical. However, 20%-40% of those infected may develop WNV disease, with symptoms ranging from fever to meningoencephalitis. A large variety of WNV strains have been described worldwide. Based on their genetic differences, they have been classified into eight lineages; the pathogenic strains belong to lineages 1 and 2. Ten years ago, Beasley et al. (2002) found that dramatic differences exist...
Wilsher S, Allen WR, Wood JL.The low productivity associated with training and racing of young Thoroughbreds (TBs) in the UK due to athletic inability, injury and disease requires further study. Objective: To identify the time points and causes of losses during growth and training phases of a cohort of 1022 TB foals born in 1999 up to the end of their third year. Methods: Movement and fate of 1022 Thoroughbred foals conceived in 1998 and born live in 1999 were monitored from birth to age 3 years. Those (n = 562) that entered training age 2 and/or 3 years with one of 161 registered trainers in Britain or Ireland in 2001/2 ...
Fukunaga Y, Kumanomido T, Kamada M.Getah virus is a member of the genus Alphavirus in the family Togaviridae and has been frequently isolated from mosquitoes. Seroepizootiologic studies indicate that the virus is mosquito-borne and widespread, ranging from Eurasia to southeast and far eastern Asia, the Pacific islands, and Australasia. The natural host animal of the virus was not known until the first recognized occurrence of Getah virus infection among racehorses in two training centers in Japan in 1978. Outbreaks of clinical disease due to Getah virus infection occur infrequently, and only one outbreak has been reported outsi...
Lu J, Guo Z, Pan X, Wang G, Zhang D, Li Y, Tan B, Ouyang L, Yu X.Avian influenza virus H5N1 has demonstrated considerable pandemic potential. Currently, no effective vaccines for H5N1 infection are available, so passive immunotherapy may be an alternative strategy. To investigate the possible therapeutic effect of antibody against highly pathogenic H5N1 virus on a mammal host, we prepared specific equine anti-H5N1 IgGs from horses vaccinated with inactivated H5N1 virus, and then obtained the F(ab')2 fragments by pepsin digestion of IgGs. Methods: The horses were vaccinated with inactivated H5N1 vaccine to prepare anti-H5N1 IgGs. The F(ab')2 fragments were p...
Mair TS, Smith LJ.Few studies have assessed short- and long-term complication rates of horses following surgical treatment of colic, a potentially fatal condition. Complications can lead to patient discomfort and increased costs; knowledge of predisposing factors may help to reduce complication rates. Objective: To document and analyse short-term complications in 300 horses undergoing colic surgery, and to assess some of the possible predisposing factors. Methods: History, clinical findings, surgical findings and procedures, and post operative treatments of 300 consecutive surgical colic cases (1994-2001) were ...
Maddox TW, Clegg PD, Diggle PJ, Wedley AL, Dawson S, Pinchbeck GL, Williams NJ.The increasing prevalence of antimicrobial-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and antimicrobial-resistant Escherichia coli represents a significant problem. However, the carriage of such bacteria by horses in the UK has not been well characterised. Objective: To estimate the prevalence of nasal carriage of MRSA and faecal carriage of antimicrobial-resistant E. coli amongst horses in the general equine community of the mainland UK. Methods: A cross-sectional study of horses recruited by 65 randomly selected equine veterinary practices was conducted, wi...
Wang LF, Michalski WP, Yu M, Pritchard LI, Crameri G, Shiell B, Eaton BT.In 1994, a new member of the family Paramyxoviridae isolated from fatal cases of respiratory disease in horses and humans was shown to be distantly related to morbilliviruses and provisionally called equine morbillivirus (K. Murray et al., Science 268:94-97, 1995). To facilitate characterization and classification, the virus was purified, viral proteins were identified, and the P/V/C gene was cloned and sequenced. The coding strategy of the gene is similar to that of Sendai and measles viruses, members of the Paramyxovirus and Morbillivirus genera, respectively, in the subfamily Paramyxovirina...
Lyons S, Kapoor A, Schneider BS, Wolfe ND, Culshaw G, Corcoran B, Durham AE, Burden F, McGorum BC, Simmonds P.Non-primate hepacivirus (NPHV), equine pegivirus (EPgV) and Theiler's disease associated virus (TDAV) are newly discovered members of two genera in the Flaviviridae family, Hepacivirus and Pegivirus respectively, that include human hepatitis C virus (HCV) and human pegivirus (HPgV). To investigate their epidemiology, persistence and clinical features of infection, large cohorts of horses and other mammalian species were screened for NPHV, EPgV and TDAV viraemia and for past exposure through serological assays for NPHV and EPgV-specific antibodies. NPHV antibodies were detected in 43% of 328 ho...
Harris SR, Robinson C, Steward KF, Webb KS, Paillot R, Parkhill J, Holden MT, Waller AS.Strangles, the most frequently diagnosed infectious disease of horses worldwide, is caused by Streptococcus equi. Despite its prevalence, the global diversity and mechanisms underlying the evolution of S. equi as a host-restricted pathogen remain poorly understood. Here, we define the global population structure of this important pathogen and reveal a population replacement in the late 19th or early 20th Century. Our data reveal a dynamic genome that continues to mutate and decay, but also to amplify and acquire genes despite the organism having lost its natural competence and become host-rest...
Allsopp MT, Lewis BD, Penzhorn BL.The intra-erythrocytic parasite Theileria equi is one of two tick-transmitted causative agents of equine piroplasmosis. Piroplasms of T. equi can be transmitted across the equine placenta and once a horse is infected, it appears to remain a lifelong carrier, since anti-theilerial drugs suppress but do not eliminate the parasite. Carrier mares may transmit the organism to their offspring and this may result in abortion or neonatal piroplasmosis, but observations by some researchers suggest that foals may be born as carriers yet remain apparently healthy. Using a T. equi-specific oligonucleotide...
Lyons ET, Tolliver SC, Drudge JH.Small strongyles are highly prevalent in horses and can be found worldwide. Even though over 50 species of these parasites have been described, about 10 species comprise the bulk of the total number present in horses. Efforts to control small strongyles and other equine internal parasites have been undertaken for many years. Some of the early medications and control measures provided questionable activity against endoparasites; whether effective or not, they could be detrimental to the horse. Beginning in the early 1900s, scientific effort was used to evaluate activity of antiparasitic compoun...
Rizk MA, El-Sayed SA, Terkawi MA, Youssef MA, El Said el Sel S, Elsayed G, El-Khodery S, El-Ashker M, Elsify A, Omar M, Salama A, Yokoyama N....A rapid and accurate assay for evaluating antibabesial drugs on a large scale is required for the discovery of novel chemotherapeutic agents against Babesia parasites. In the current study, we evaluated the usefulness of a fluorescence-based assay for determining the efficacies of antibabesial compounds against bovine and equine hemoparasites in in vitro cultures. Three different hematocrits (HCTs; 2.5%, 5%, and 10%) were used without daily replacement of the medium. The results of a high-throughput screening assay revealed that the best HCT was 2.5% for bovine Babesia parasites and 5% for equ...
Smith KC, Blunden AS, Whitwell KE, Dunn KA, Wales AD.A detailed review of laboratory records for equine abortion is fundamental in establishing current disease trends and suggesting problems important for further research. Objective: To review the causes of abortion and neonatal death in equine diagnostic submissions to the Animal Health Trust over a 10 year period. Methods: The diagnoses in 1252 equine fetuses and neonatal foals were reviewed and analysed into categories. Results: Problems associated with the umbilical cord, comprising umbilical cord torsion and the long cord/cervical pole ischaemia disorder, were the most common diagnoses (38....
Bagcigil FA, Moodley A, Baptiste KE, Jensen VF, Guardabassi L.beta-Lactams and macrolides are important antibiotics for treatment of staphylococcal infections in both humans and animals. The aim of the study was to investigate the occurrence, species distribution and clonality of methicillin- and erythromycin-resistant staphylococci in the nasal cavity of dogs, horses, pigs, and cattle in Denmark. Nasal swabs were collected from a total of 400 animals, including 100 individuals of each species. Methicillin- and erythromycin-resistant staphylococci were isolated on selective media, identified by 16S rDNA sequencing, and typed by pulsed field gel electroph...
Sheats MK.The most recent definition of sepsis in human medicine can be summarized as organ dysfunction caused by a dysregulated host response to infection. In equine medicine, although no consensus definition is available, sepsis is commonly described as a dysregulated host systemic inflammatory response to infection. Defense against host infection is the primary role of innate immune cells known as neutrophils. Neutrophils also contribute to host injury during sepsis, making them important potential targets for sepsis prevention, diagnosis, and treatment. This review will present both historical and u...
Jacobsen S, Niewold TA, Halling-Thomsen M, Nanni S, Olsen E, Lindegaard C, Andersen PH.The aim of the study was to determine the intraarticular serum amyloid A (SAA) response pattern in horses with inflammatory arthritis. Inflammatory arthritis was induced by injection of lipopolysaccharide (LPS) into the radiocarpal joint of four horses. Serum and synovial fluid (SF) samples were collected before and at 4, 8, 12, 24, 48, 72, 96, and 144 h after injection. Concentrations of SAA were measured by immunoturbidometry, and expression of SAA isoforms was visualized by denaturing isoelectric focusing and Western blotting. The LPS injection caused systemic and local clinical signs of in...
