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.
Dynon K, Varrasso A, Ficorilli N, Holloway S, Reubel G, Li F, Hartley C, Studdert M, Drummer H.To develop rapid (< 8 hour) tests using polymerase chain reaction (PCR) for the diagnosis of equine herpesvirus 3 (EHV3; equine coital exanthema virus), equine gammaherpesviruses 2 (EHV2) and EHV5, equine adenovirus 1 (EAdV1), EAdV2, equine arteritis virus (EAV), equine rhinitis A virus (ERAV; formerly equine rhinovirus 1) Methods: Either single round or second round (seminested) PCRs were developed and validated. Methods: Oligonucleotide primers were designed that were specific for each virus, PCR conditions were defined and the specificity and sensitivity of the assays were determined. The a...
Nally JE, Artiushin S, Timoney JF.Leptospira interrogans is a mammalian pathogen which must adapt to a range of new environmental conditions including temperature change when it infects new hosts. In vitro studies of organisms cultured at 30 degrees C and shifted to 37 degrees C for 5 to 7 days have confirmed that synthesis of several proteins involved in equine infection is regulated in response to temperature change (J. E. Nally, J. F. Timoney, and B. Stevenson, Infect. Immun. 69:400-404, 2001). In order to specifically identify antigenic proteins upregulated at 37 degrees C, groups of three ponies were immunized with organi...
Furrer E, Bilzer T, Stitz L, Planz O.Experimental Borna disease virus (BDV) infection of rats and natural infection of horses and sheep leads to severe central nervous system disease based on immunopathological pathways. The virus replicates slowly, and the cellular immune response results in immunopathology. CD8(+) T cells exert effector cell functions, and their activity results in the destruction of virus-infected cells. Previously, Oldach and colleagues (D. Oldach, M. C. Zink, J. M. Pyper, S. Herzog, R. Rott, O. Narayan, and J. E. Clements, Virology 206:426-434, 1995) have reported protection against Borna disease after inocu...
Queiroz AO, Legey AP, Xavier SC, Jansen AM."Mal de Cadeiras", an enzootic disease caused by Trypanosoma evansi, is one of the most important trypanosomiases in the Brazilian Pantanal region. The disease affects mainly horses, which are widely used in extensive cattle production, an activity of greatest economical significance for the region. The parasite also infects sylvan (coatis and capybaras) and domestic (dogs) animals, respectively considered wild and domestic reservoirs of T. evansi. For a better understanding of the interaction of T. evansi with its rodent host, we evaluated the differences in the specific antibody level patter...
Mealey RH, Fraser DG, Oaks JL, Cantor GH, McGuire TC.Acute infection with equine infectious anemia virus (EIAV), a lentivirus of horses, results in a persistent high-level viremia in Arabian foals affected with severe combined immunodeficiency (SCID). This observation argues against the idea that the transient nature of acute lentiviral viremia is solely a function of viral population dynamics. To extend these studies, EIAV-specific immune reconstitution was attempted prior to EIAV challenge in two SCID foals, using adoptively transferred virus-stimulated lymphocytes derived from persistently EIAV-infected half sibling donors. Following transfer...
Barros AT.Once a month, from June 1992 to May 1993, collections of tabanids on horse were conducted in the Nhecolândia, Pantanal State of Mato Grosso do Sul, Brazil. Tabanid catches using hand nets were conducted from sunrise to sunset at grassland and cerradão (dense savanna) habitats. A total of 3,442 tabanids from 21 species,12 genera, and 3 subfamilies were collected. Although species abundance varied seasonally depending on habitat, no habitat specificity was observed for the most abundant species. In the grassland, 1,625 (47.2%) tabanids belonging to 19 species were collected, while 1,817 (52.8%...
Weese JS, Baird JD, Poppe C, Archambault M.Salmonella Typhimurium definitive type 104 (DT104) has emerged as a common cause of salmonellosis in humans and cattle, yet previous reports involving horses are sparse. This study reports the emergence of DT104 as an important pathogen in horses in Ontario. The first clinical case of DT104 infection at the Ontario Veterinary College was identified in 1997. Seventeen cases of DT104-associated salmonellosis were identified between 1997 and 2000. In 2000, 12 of 13 cases of salmonellosis were due to DT104. Salmonellosis in horses due to DT104 is of concern, since the organism is multiresistant to...
Huang JA, Ficorilli N, Hartley CA, Wilcox RS, Weiss M, Studdert MJ.Equine rhinovirus serotype 3 isolate P313/75 was assigned, with an unclassified genus status, to the family PICORNAVIRIDAE: The sequence from the 5' poly(C) tract to the 3' poly(A) tract of P313/75 was determined. The sequence is 8821 bases in length and contains a potential open reading frame for a polyprotein of 2583 amino acids. Sequence comparison and phylogenic analysis suggest that P313/75 is most closely related to the prototype equine rhinitis B virus (ERBV) strain P1436/71, formerly named equine rhinovirus type 2. A high degree of sequence similarity was found in the P2 and P3 regions...
Hullinger PJ, Gardner IA, Hietala SK, Ferraro GL, MacLachlan NJ.To compare seroprevalence of antibodies against equine arteritis virus (EAV) in horses residing in the United States with that of imported horses. Methods: Serologic survey. Methods: Serum samples from 364 horses on 44 equine operations in California and 226 horses imported from various countries. Methods: Serum samples were collected from each imported horse and from up to 20 horses on each operation. For resident horses, the number of sampled horses on each operation was determined on the basis of the number of horses on the operation. Samples were tested for antibodies against EAV by use of...
Dobbe JC, van der Meer Y, Spaan WJ, Snijder EJ.The recent development of arterivirus full-length cDNA clones makes possible the construction of chimeric arteriviruses for fundamental and applied studies. Using an equine arteritis virus (EAV) infectious cDNA clone, we have engineered chimeras in which the ectodomains of the two major envelope proteins, the glycoprotein GP(5) and the membrane protein M, were replaced by sequences from envelope proteins of related and unrelated RNA viruses. Using immunofluorescence microscopy, we monitored the transport of the hybrid GP(5) and M proteins to the Golgi complex, which depends on their heterodime...
Matthews S, Dart AJ, Dowling BA, Hodgson JL, Hodgson DR.To review the clinical findings, diagnosis and treatment of 51 horses with peritonitis attributed to Actinobacillus equuli. Methods: Retrospective study of clinical cases. Methods: Breed, age and gender of horse, history, physical examination findings, treatment and outcome were determined from the hospital records of 51 horses in which a diagnosis of peritonitis attributed to A. equuli was made between January 1993 and June 1999. Results of abdominal fluid cytology and bacteriology, antimicrobial sensitivity patterns, haematology and faecal egg counts, when performed, were also retrieved. Res...
Kershaw O, von Oppen T, Glitz F, Deegen E, Ludwig H, Borchers K.The prevalence of EHV-2 in 27 horses with keratoconjunctivitis and 21 clinically healthy horses of different ages and stocks were analyzed. We demonstrated that EHV-2 was present in 12 keratoconjunctivitis cases as shown by nested PCR on ocular swabs. This is statistically more often than in the control group, where only two ocular swabs were EHV-2 positive. Cocultivation was successful on peripheral blood leukocytes of healthy and diseased horses but not on swabs. We isolated ten EHV-2 strains from diseased and nine from control horses, whereas 16 isolates showed different restriction enzyme ...
Ostlund EN, Crom RL, Pedersen DD, Johnson DJ, Williams WO, Schmitt BJ.After the 1999 outbreak of West Nile (WN) encephalitis in New York horses, a case definition was developed that specified the clinical signs, coupled with laboratory test results, required to classify cases of WN encephalitis in equines as either probable or confirmed. In 2000, 60 horses from seven states met the criteria for a confirmed case. The cumulative experience from clinical observations and diagnostic testing during the 1999 and 2000 outbreaks of WN encephalitis in horses will contribute to further refinement of diagnostic criteria.
Nicolaiewsky TB, Richter MF, Lunge VR, Cunha CW, Delagostin O, Ikuta N, Fonseca AS, da Silva SS, Ozaki LS.We describe a nested polymerase chain reaction (PCR) for the detection of Babesia equi in equine infected erythrocytes using oligonucleotides designed on the published sequence of a B. equi merozoite antigen gene (ema-1). A 102bp DNA fragment is specifically amplified from B. equi but not from Babesia caballi, Babesia bovis or Babesia bigemina DNA. In a mock infection we were able to detect down to six infected cells in 10(8) equine erythrocytes or to detect the parasite in blood with an equivalent parasitemia of 0.000006%. Furthermore, gene polymorphism was found by performing a PCR-RFLP (PCR...
Faye D, Pereira de Almeida PJ, Goossens B, Osaer S, Ndao M, Berkvens D, Speybroeck N, Nieberding F, Geerts S.In a study of the prevalence and incidence of trypanosomosis in horses and donkeys in two regions of the Gambia, surveys were carried out at Niamina east and Bansang south with a high and low to moderate tsetse challenge, respectively. Eleven horses and 67 donkeys were sampled monthly from August 1997 to September 1998. Blood samples were examined for trypanosomes using the buffy-coat (BC) method and polymerase chain reaction (PCR). Three primer sets were used, specific for either Trypanosoma vivax (TVW), Trypanosoma congolense (GOL) or Trypanosoma brucei (ORPHON5J). The BC results showed that...
Trock SC, Meade BJ, Glaser AL, Ostlund EN, Lanciotti RS, Cropp BC, Kulasekera V, Kramer LD, Komar N.West Nile (WN) virus was identified in the Western Hemisphere in 1999. Along with human encephalitis cases, 20 equine cases of WN virus were detected in 1999 and 23 equine cases in 2000 in New York. During both years, the equine cases occurred after human cases in New York had been identified.
Johnson DJ, Ostlund EN, Pedersen DD, Schmitt BJ.A traditional single-stage reverse transcription-polymerase chain reaction (RT-PCR) procedure is effective in determining West Nile (WN) virus in avian tissue and infected cell cultures. However, the procedure lacks the sensitivity to detect WN virus in equine tissue. We describe an RT-nested PCR (RT-nPCR) procedure that identifies the North American strain of WN virus directly in equine and avian tissues.
Komar N, Panella NA, Boyce E.We evaluated West Nile (WN) virus seroprevalence in healthy horses, dogs, and cats in New York City after an outbreak of human WN virus encephalitis in 1999. Two (3%) of 73 horses, 10 (5%) of 189 dogs, and none of 12 cats tested positive for WN virus-neutralizing antibodies. Domestic mammals should be evaluated as sentinels for local WN virus activity and predictors of the infection in humans.
Hadler J, Nelson R, McCarthy T, Andreadis T, Lis MJ, French R, Beckwith W, Mayo D, Archambault G, Cartter M.In 1999, Connecticut was one of three states in which West Nile (WN) virus actively circulated prior to its recognition. In 2000, prospective surveillance was established, including monitoring bird deaths, testing dead crows, trapping and testing mosquitoes, testing horses and hospitalized humans with neurologic illness, and conducting a human seroprevalence survey. WN virus was first detected in a dead crow found on July 5 in Fairfield County. Ultimately, 1,095 dead crows, 14 mosquito pools, 7 horses, and one mildly symptomatic person were documented with WN virus infection. None of 86 hospit...
Marfin AA, Gubler DJ.In 1999, an epidemic of West Nile virus (WNV) encephalitis occurred in New York City (NYC) and 2 surrounding New York counties. Simultaneously, an epizootic among American crows and other bird species occurred in 4 states. Indigenous transmission of WNV had never been documented in the western hemisphere until this epidemic. In 2000, the epizootic expanded to 12 states and the District of Columbia, and the epidemic continued in NYC, 5 New Jersey counties, and 1 Connecticut county. In addition to these outbreaks, several large epidemics of WNV have occurred in other regions of the world where t...
Takai S, Henton MM, Picard JA, Guthrie AJ, Fukushi H, Sugimoto C.The prevalence of virulent Rhodococcus equi in soil isolates from two horse farms in South Africa and nine clinical isolates from six foals, a foal foetus, a dog, and a monkey was investigated. The isolates were tested for the presence of virulence plasmid DNA and 15- to 17-kDa antigens by immunoblotting. Rhodococcus equi was isolated from almost all of the soil samples obtained from the two farms with 5.0 x 10(1) to 3.3 x 10(4) colony forming units per gram of soil. Virulent R. equi was isolated from three soil samples from one of the farms and appeared in 3.8% (three of 80 isolates), but not...
Murgue B, Murri S, Zientara S, Durand B, Durand JP, Zeller H.On September 6, 2000, two cases of equine encephalitis caused by West Nile (WN) virus were reported in southern France (Hérault Province), near Camargue National Park, where a WN outbreak occurred in 1962. Through November 30, 76 cases were laboratory confirmed among 131 equines with neurologic disorders. The last confirmed case was on November 3, 2000. All but three cases were located in a region nicknamed "la petite Camargue," which has several large marshes, numerous colonies of migratory and resident birds, and large mosquito populations. No human case has been confirmed among clinically ...
Nordengrahn A, Klingeborn B, Lindholm A, Merza M.A blocking enzyme-linked immunosorbent assay (ELISA) was developed to detect antibodies to equine herpesvirus 2 in serum samples of horses. By measuring the binding to a single epitope, this blocking ELISA gives a good picture of the antibody status in the animal. The test is based on a monoclonal antibody with neutralizing activity and had a sensitivity of 94% and a specificity of 100%. Antibodies due to newly acquired infection in foals were successfully detected with this blocking ELISA.
Varrasso A, Drummer HE, Huang JA, Stevenson RA, Ficorilli N, Studdert MJ, Hartley CA.The nucleotide and deduced amino acid sequences of the P1 region of the genomes of 10 independent equine rhinitis A virus (ERAV) isolates were determined and found to be very closely related. A panel of seven monoclonal antibodies to the prototype virus ERAV.393/76 that bound to nonneutralization epitopes conserved among all 10 isolates was raised. In serum neutralization assays, rabbit polyclonal sera and sera from naturally and experimentally infected horses reacted in a consistent and discriminating manner with the 10 isolates, which indicated the existence of variation in the neutralizatio...
Jang HK, Albrecht RA, Buczynski KA, Kim SK, Derbigny WA, O'Callaghan DJ.The sole immediate-early (IE) gene of equine herpesvirus 1 encodes a 1,487-amino-acid (aa) regulatory phosphoprotein that independently activates expression of early viral genes. Coimmunoprecipitation assays demonstrated that the IE protein physically interacts with the general transcription factor TFIIB. Using a variety of protein-binding assays that employed a panel of IE truncation and deletion mutants expressed as in vitro-synthesized or glutathione S-transferase fusion proteins, we mapped a TFIIB-binding domain to aa 407 to 757 of the IE protein. IE mutants carrying internal deletions of ...
Dutra F, Schuch LF, Delucchi E, Curcio BR, Coimbra H, Raffi MB, Dellagostin O, Riet-Correa F.A disease named locally as churrío or churrido equino (i.e., equine scours) has occurred for at least 100 years in Uruguay and southern Brazil in farms along both shores of the Merín lake. This report describes cases of churrido equino and provides serologic, pathologic, and DNA-based evidence indicating that the disease is in fact equine monocytic ehrlichiosis (Potomac horse fever). Results of an epidemiological investigation conducted on an endemic farm are also presented. Clinical signs in 12 horses were fever, depression, diarrhea, dehydration, and sometimes colic and distal hind limb ed...
Duggan JM, Coates DM, Ulaeto DO.Venezuelan equine encephalomyelitis (VEE) virus is an important human and veterinary pathogen of Central and South America. The virus can cause widespread epidemics, affecting hundreds of thousands of horses, and thousands of humans. Detection of the virus early in infection and in mosquito populations may allow epidemics to be predicted such that suitable prophylaxis, such as vaccination, can be used to reduce disease severity and transmission. The sensitivity and specificity of current immunoassays, based on conventional monoclonal and polyclonal antibodies, needs to be improved for the diag...
Langley RL, Hunter JL.To better understand the extent of animal-related fatalities in the workplace. Methods: This study utilized Census of Fatal Occupational Injuries files from the US Department of Labor for the years 1992-1997 to describe the events surrounding human workplace fatalities associated with animals. Results: During the 6-year time period, 350 workplace deaths could be associated with an animal-related event. Cattle and horses were the animals primarily involved, and workers in the agricultural industry experienced the majority of events. Many deaths involved transportation events, either direct coll...
Cohen D, Bosler EM, Bernard W, Meirs D, Eisner R, Schulze TL.A serologic survey of horses in the New Jersey-Pennsylvania area demonstrated that about 10% (6.2-14.2%) have significant levels of serum antibody to Borrelia burgdorferi. However, in a highly endemic area of central New Jersey, up to 60% of the mares and yearlings samples on one farm were seropositive. In 1983, sera from this same farm exhibited only 12% positives in mares and 35% positives in yearlings. Longitudinal studies of paired sera obtained from individual yearlings over a 6-month period in 1985 showed that 34% of them declined during the period. A new clinical syndrome associated wit...
Santos EM, Cardoso R, Souza GR, Goulart LR, Heinemann MB, Leite RC, Reis JK.Equine infectious anemia caused by equine infectious anemia virus is an important disease due to its high severity and incidence in animals. We used a phage display library to isolate peptides that can be considered potential markers for equine infectious anemia diagnosis. We selected peptides using IgG purified from a pool comprised of 20 sera from animals naturally infected with equine infectious anemia virus. The diagnostic potential of these peptides was investigated by ELISA, Western blot and dot blot with purified IgG and serum samples. Based on the results, we chose a peptide mimetic fo...
Studdert MJ, Fitzpatrick DR, Horner GW, Westbury HA, Gleeson LJ.Representative strains of EHV isolated from an aborted foetus and from a horse with rhinopneumonitis in New Zealand had restriction endonuclease DNA fingerprints typical of those usually associated with these syndromes elsewhere and now designated EHV1 and 4 respectively. EHV1 was isolated from the brain and spinal cord of a 4-year-old gelding that died of myeloencephalitis. A mare on the same farm, at about the same time as the gelding developed myeloencephalitis, aborted and EHV1 was isolated from the tissues of the aborted foetus. Restriction endonuclease DNA fingerprints of the viruses iso...
Yin X, Lu G, Guo W, Qi T, Ma J, Zhu C, Zhao S, Pan J, Xiang W.An outbreak of equine influenza was observed in the Asian wild horse population in Xinjiang Province, China, in 2007. Nasal swabs were collected from wild horses and inoculated into 9-10-day SPF embryonated eggs. The complete genome of the isolate was sequenced. A comparison of the amino acid sequence revealed that the isolate was an equine influenza virus strain, which we named A/equine/Xinjiang/4/2007. Each gene of the virus was found to have greater than 99 % homology to equine influenza virus strains of the Florida-2 sublineage, which were circulating simultaneously in China, and a lesser ...
El-Hage CM, Bannai H, Wiethoelter AK, Firestone SM, Heislers CM, Allen JL, Waller AS, Gilkerson JR.To determine the nature of serological responses in Australian horses using a commercial duplex indirect ELISA (iELISA) following vaccination against strangles. Methods: A group (n = 19) of client-owned horses from five properties were recruited to receive a primary course of a Streptococcus equi subsp. equi (S. equi) extract vaccine. Serological responses were determined by duplex iELISA incorporating S. equi-specific fragments of two cell wall proteins, SEQ2190 and SeM (antigens (Ag) A and C, respectively). Methods: The horses were administered a primary strangles vaccination course. Blood w...
Shen DT, Crawford TB, Gorham JR, McGuire TC.Twelve chemicals and commercial disinfectants were tested for inactivation of equine infectious anemia virus. In the presence of 10% bovine serum, all chemicals inactivated 4 log10 (based on 0.1 ml) of the virus within 5 minutes at 23 C. A reduction of at least 4 log10 was observed when the virus was exposed for 1 minute to substituted phenolic disinfectants (3 commercial preparations and sodium orthophenylphenate), halogen derivatives (iodophor and sodium hypochlorite), chlorhexidine, and 70% ethanol. Sodium hydroxide (5%), 2% formalin, and 2% glutaraldehyde were slower to inactivate the viru...
Hassanien RT, Hussein HA, Abdelmegeed HK, Abdelwahed DA, Khattab OM, Ali MH, Habashi AR, Ibraheem EM, Shahein MA, Abohatab EM.Due to climatic changes, arthropod-borne viruses have become a global health concern. In Egypt, West Nile virus (WNV) was initially detected in humans in 1950 and then in 1951, 1954, 1968, and 1989. Although WNV infection has been recorded in numerous Middle Eastern countries, its prevalence among the equine population in Egypt is unknown. This study aimed to investigate the current situation of vector-borne WNV in Egypt, estimate its seroprevalence, and assess the associated risk factors. Unassigned: We screened 1100 sera samples and nasal swabs from the same equids, 156 mosquito pools, and 3...
McFadden AM, Pearce PV, Orr D, Nicoll K, Rawdon TG, Pharo H, Stone M.To summarise investigation and laboratory data collected between 2001 and 2011 to provide evidence that equine arteritis virus is not present in the horse population of New Zealand. Methods: Analysis was carried out on results from laboratory tests carried out at the Ministry for Primary Industries Animal Health Laboratory (AHL) for equine arteritis virus from horses tested prior to being imported or exported, testing of stallions as part of the New Zealand equine viral arteritis (EVA) control scheme and testing as part of transboundary animal disease (TAD) investigations for exclusion of EVA....
Sturgill TL, Giguère S, Franklin RP, Cohen ND, Hagen J, Kalyuzhny AE.The objectives of the present study were to determine if administration of inactivated parapoxvirus ovis (IPPVO) can decrease the cumulative incidence of pneumonia and increase the number of IFN-γ- and IL-4-secreting cells among foals. Fifty-nine foals were randomly assigned to 2 treatment groups (IPPVO or placebo) prior to birth. At 24-48 h of age, foals received 2 ml of either IPPVO or a placebo by intramuscular injection. Injections were repeated 24h and 8 days later. The number of IFN-γ- and IL-4-secreting cells was measured using a validated ELISPOT assay on blood mononuclear cells coll...
Cheevers WP, Fatemi-Nainie S, Anderson LW.A retrovirus is spontaneously released into the culture medium of the equine sarcoid-derived MC-1 cell line. The MC-1 virus did not exhibit in vitro transforming activity or replication when tested on equine fibroblasts or a variety of other mammalian cell cultures. Complementary DNA, synthesized using detergent-activated MC-1 virus RNA-dependent DNA polymerase, detected homologous sequences in the DNA of an established equine dermal cell line and in the DNA of primary equine dermal fibroblasts. Iododeoxyuridine or azacytidine induced a replication-deficient endogenous retrovirus in the normal...
Dale B, Brown R, Miller J, White RT, Air GM, Cordell B.Equine influenza is caused by two serotypes of type A influenza virus, EIV-A1 and EIV-A2. The complete nucleotide sequence of the neuraminidase (NA) genes of both the A1 (N7 subtype) and A2 (N8 subtype) serotype has been determined following cloning of full-length viral NA cDNAs into pBR322. Analysis of the deduced amino acid sequences reveals that the N7 and N8 genes share expected extensive homologies with the previously sequenced N1, N2, and N9 NA subtypes. These homologies include conservation of basic NA gene and protein structure, cysteine residues, potential glycosylation sites, and res...
French DD, Klei TM, Foil CS, Miller RI, Foil LD, Chapman MR, McClure JJ.The efficacy of a single dose of ivermectin (0.2 mg/kg), in injectable or paste formulations, against microfilariae of Onchocerca cervicalis and associated skin lesions was evaluated in 20 naturally infected horses during midsummer months in Louisiana. All horses had clinical signs of dermatitis of the ventral midline and/or limbs, shoulders, thorax, and withers. Efficacy was monitored at 21, 42, and 63 days after treatment. Procedures done at these intervals included microfilarial counts of 6-mm skin biopsy specimens of affected ventral midline, grading of gross lesions, and photography and h...
Madrigal-Valencia TL, Saavedra-Montañez M, Pérez-Torres A, Hernández J, Segalés J, Hernández YD, Candanosa-Aranda IE, Pérez-Guiot A....Ovine gammaherpesvirus 2 (OvHV-2), a member of the genus Macavirus, causes sheep-associated malignant catarrhal fever (SA-MCF), a fatal lymphoproliferative disease affecting a wide variety of ungulates in addition to horses. This study described an outbreak of SA-MCF in Mexico and the identification of the OvHV-2 virus in primary rabbit testis cultures through the generation of intranuclear inclusion bodies, syncytia, immunofluorescence (IF), immunocytochemistry (ICC), immunohistochemistry (IHC), endpoint polymerase chain reaction (PCR), and partial sequencing of the ORF75 gene. The animals in...
Traversa D, Otranto D, Iorio R, Giangaspero A.Equine thelaziosis caused by the eyeworm Thelazia lacrymalis is a parasitic disease transmitted by muscid flies. Although equine thelaziosis is known to have worldwide distribution, information on the epidemiology and presence of the intermediate hosts of T. lacrymalis is lacking. In the present work, a PCR-RFLP based assay on the first and/or second internal transcribed spacer (ITS1 and ITS2) of ribosomal DNA was developed for the detection of T. lacrymalis DNA in its putative vector(s). The sensitivity of the technique was also assessed. The restriction patterns obtained readily differentiat...
Keane DP, Little PB, Wilkie BN, Artsob H, Thorsen J.A survey was conducted by testing 115 paired equine serum and cerebrospinal fluid samples by hemagglutination-inhibition for antibodies to Powassan and snowshoe hare viruses, and by virus neutralization for antibodies to equine herpesvirus type 1. Twenty-five samples were from horses with spontaneous neurological disease and the remainder from horses euthanized because of various nonneurological disorders. All sera and cerebrospinal fluids were negative for antibodies to Powassan virus. Fifty-one sera (44.3%) and 15 cerebrospinal fluids (13.0%) had antibodies to snowshoe hare virus. Ninety-eig...
Nunes JDSDSS, Casseb LMN, Guimarães RJPS, Reis WDM, de Barros BCV, Ferreira MS, Chiang JO, Pinheiro HHC, Vasconcelos PFDC, Cruz ACR.Serum samples from 89 equids were analyzed (75 horses, 9 donkeys, and 5 mules) from the municipality of Viseu, Pará state, Brazil. Samples were collected in November 2014 and August 2015. The antibody prevalence against the following alphaviruses was estimated: Eastern equine encephalitis virus, Western equine encephalitis virus, Mucambo virus, and Mayaro virus. Seroprevalence was determined by the hemagglutination inhibition (HI) technique. Sera that exhibited HI antibodies with heterotypic reactions for the analyzed viruses were subjected to the 90% plaque reduction neutralization test (PRN...
Horsington JJ, Gilkerson JR, Hartley CA.Erbovirus is a genus of the family Picornaviridae and equine rhinitis B virus (ERBV) is the sole species. Erboviruses infect horses causing acute respiratory disease and sub-clinical and persistent infections. Despite the high seroprevalence and worldwide distribution of these viruses, the pathogenesis and antigenic structure of the three ERBV serotypes (ERBV1, 2 and 3) is poorly understood. To characterise linear epitopes on ERBV structural proteins, a set of fusion proteins were expressed in Escherichia coli. These proteins were tested in Western blot and ELISA and reactive proteins were als...
Thompson JA, Brown SE, Riddle WT, Seahorn JC, Cohen ND.To estimate spatial risks associated with mare reproductive loss syndrome (MRLS) during 2001 among horses in a specific study population and partition the herd effects into those attributable to herd location and those that were spatially random and likely attributable to herd management. Animals-Pregnant broodmares from 62 farms in 7 counties in central Kentucky. Methods: Veterinarians provided the 2001 abortion incidence proportions for each farm included in the study. Farms were georeferenced and data were analyzed by use of a fully Bayesian risk-mapping technique. Results: Large farm-to-fa...
Mayo C, Venter E, Steyn J, Coetzee P, van Vuuren M, Crafford J, Schütte C, Venter G.The seasonal abundance of Culicoides midges, the vector of Bluetongue and African horse sickness viruses (BTV/AHSV) and the presence of viruses in midges were determined in 3 geographic areas in South Africa. In the Onderstepoort area, more than 500,000 Culicoides midges belonging to 27 species were collected. Eighteen midge species were collected throughout Winter and the presence of AHSV and BTV RNA in midges was detected using real time reverse transcription quantitative polymerase chain reaction. The nucleic acid of AHSV was found in 12 pools out of total pools of 35 Culicoides. Twenty‑f...
Hlokwe TM, Sutton D, Page P, Michel AL.Tuberculosis caused by Mycobacterium bovis (M. bovis) is very uncommon in horses worldwide. Methods: In the current study, an eight-year-old male Thoroughbred in good body condition was admitted to the Equine Clinic at the Onderstepoort Veterinary Academic Hospital in 2005 due to bilateral epistaxis accompanied by coughing. Routine examinations were conducted to determine the cause of the condition. Endoscopic examination revealed the major source of the epistaxis as the trachea, whereas thoracic radiography indicated the presence of a primary pulmonary mass. M. bovis was isolated from a bronc...
Holman PJ, Becu T, Bakos E, Polledo G, Cruz D, Wagner GG.Babesia equi, a causative agent of equine piroplasmosis, was isolated from horses in the Chaco Province of Argentina, a known piroplasmosis endemic region. Fifteen B. equi field isolates were acquired by culture from 23 actively working horses from 2 ranches. The horses appeared healthy with no clinical signs or histories indicative of equine piroplasmosis. All 23 horses had B. equi-specific antibody activity by the indirect fluorescent antibody test and 18 were also complement fixation test positive for B. equi. Equine erythrocytes were prepared for parasite culture using a microcentrifuge tu...
Walker RL, de Peralta TL, Villanueva MR, Snipes KP, Madigan JE, Hird DW, Kasten RW.Isolates of Salmonella choleraesuis serotype ohio (S. ohio) recovered during an outbreak of equine neonatal salmonellosis on a Thoroughbred farm were compared with isolates of the same serotype from various animal, feed and environmental sources. Biochemical profiles, antimicrobial susceptibility patterns, phage susceptibility, plasmid profiles, restriction endonuclease analysis and ribotyping were used to compare relatedness of the strains. A total of 46 outbreak and non-outbreak associated isolates of S. ohio were studied. Differences in antimicrobial susceptibility patterns, phage susceptib...
Nurcahyo W, Yowi MRK, Hartati S, Prastowo J.Horses have a strategic and vital role to play in the lives of the people of Sumba Island, East Nusa Tenggara Province. They act as social animals that are involved in death ceremonies, horse races, and during pasola, thereby supporting tourism, and are given away as dowry in wedding ceremonies. This study aimed to investigate the prevalence of trypanosomiasis among horses in four districts of Sumba Island by examining clinical symptoms and detecting parasites, antibodies, and other factors that are related to infection in horses. Methods: We studied a total of 211 horses that belonged to 88 ...
Stejskalova K, Janova E, Horecky C, Horecka E, Vaclavek P, Hubalek Z, Relling K, Cvanova M, D'Amico G, Mihalca AD, Modry D, Knoll A, Horin P.The West Nile virus (WNV) is a mosquito-borne flavivirus causing meningoencephalitis in humans and animals. Due to their particular susceptibility to WNV infection, horses serve as a sentinel species. In a population of Romanian semi-feral horses living in the Danube delta region, we have analyzed the distribution of candidate polymorphic genetic markers between anti WNV-IgG seropositive and seronegative horses. Thirty-six SNPs located in 28 immunity-related genes and 26 microsatellites located in the MHC and LY49 complex genomic regions were genotyped in 57 seropositive and 32 seronegative ho...
Ruple-Czerniak AA, Aceto HW, Bender JB, Paradis MR, Shaw SP, Van Metre DC, Weese JS, Wilson DA, Wilson J, Morley PS.Methods that can be used to estimate rates of healthcare-associated infections and other nosocomial events have not been well established for use in equine hospitals. Traditional laboratory-based surveillance is expensive and cannot be applied in all of these settings. Objective: To evaluate the use of a syndromic surveillance system for estimating rates of occurrence of healthcare-associated infections among hospitalised equine cases. Methods: Multicentre, prospective longitudinal study. Methods: This study included weaned equids (n = 297) that were admitted for gastrointestinal disorders at ...
Wilsher S, Omar H, Ismer A, Allen T, Wernery U, Joseph M, Mawhinney I, Florea L, Thurston L, Duquesne F, Petry S.Three horse mares inadvertently inseminated with semen from a Tayorella asinigenitalis-positive Jack donkey developed severe, purulent endometritis whereas two Jenny donkeys mated naturally to the same Jack donkey did not develop clinical signs of infection. Objective: To isolate and identify the causative agent. Methods: Case report. Methods: Endometrial swabs from the infected mares were cultured on selective and non-selective media under aerobic and microaerophilic conditions. Isolates were subjected to Gram staining, oxidase and catalase tests, the Monotayl Latex Agglutination test and PCR...
Hannant D, O'Neill T, Ostlund EN, Kydd JH, Hopkin PJ, Mumford JA.A paresis isolate of equid herpesvirus 1 (EHV1, Ab4/8) and a plaque-purified virus derived from it (EHV1, Ab4/13), induced long-term suppression of both mitogenic and antigen-specific lymphocyte proliferations in adult outbred ponies. Peripheral blood mononuclear cells (PBMC) taken from a pony after EHV1 infection suppressed the in vitro function of normal cells but serum did not. This showed that the observed immune suppression was associated with circulating PBMC and/or their products rather than circulating soluble factors such as antigen or immune complexes. The results suggested that prod...
Pouwels HG, Van de Zande SM, Horspool LJ, Hoeijmakers MJ.Assessing the ability of current equine influenza vaccines to provide cross-protection against emerging strains is important. Horses not vaccinated previously and seronegative for equine influenza based on haemagglutination inhibition (HI) assay were assigned at random to vaccinated (n=7) or non-vaccinated (control, n=5) groups. Vaccination was performed twice four weeks apart with a 1 ml influenza subunit (A/eq/Prague/1/56, A/eq/Newmarket/1/93, A/eq/Newmarket/2/93), tetanus toxoid vaccine with Matrix-C adjuvant (EquilisPrequenza Te). All the horses were challenged individually by aerosol wi...
Boulanger P, Bannister GL, Ruckerbauer GM, Corner AH.Clinical field cases of equine infectious anemia were studied and the disease was reproduced experimentally in horses. Attempts were made to adapt the complement-fixation test to the detection of antibodies in the serum of infected animals and to the demonstration of antigens in tissue extracts.A moderate complement-fixing antibody response was demonstrated in the serum of horses shortly after primary exposure to the infectious agent. However, this reactivity was of short duration and occurred with normal as well as with infected saline tissue extracts. It was therefore concluded that this rea...
Kawakami V, Rietberg K, Lipton B, Eckmann K, Watkins M, Oltean H, Kay M, Rothschild C, Kobayashi M, Van Beneden C, Duchin J.On March 17, 2016, Public Health-Seattle & King County in Washington was notified of two persons who received a diagnosis of Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) infections. S. zooepidemicus is a zoonotic pathogen that rarely causes human illness and is usually associated with consuming unpasteurized dairy products or with direct horse contact (1). In horses, S. zooepidemicus is a commensal bacterium that can cause respiratory, wound, and uterine infections (2). The health department investigated to determine the magnitude of the outbreak, identify risk factors, and o...
