Epidemiology in horses involves the study of the distribution and determinants of health-related states and events in equine populations. It encompasses the investigation of patterns, causes, and effects of diseases and health conditions within horse populations. This field of study aims to identify risk factors for disease and targets for preventive healthcare. Key components of equine epidemiology include disease surveillance, outbreak investigation, and the study of disease dynamics within herds or regions. Research in this area often focuses on infectious diseases, zoonotic diseases, and the impact of environmental factors on equine health. This page compiles peer-reviewed research studies and scholarly articles that explore various aspects of epidemiology in horses, including disease prevalence, transmission pathways, and strategies for disease prevention and control.
Ernst NS, Hernandez JA, MacKay RJ, Brown MP, Gaskin JM, Nguyen AD, Giguere S, Colahan PT, Troedsson MR, Haines GR, Addison IR, Miller BJ.To estimate prevalence of and identify risk factors for fecal Salmonella shedding among hospitalized horses with signs of gastrointestinal tract disease. Methods: Cross-sectional study. Methods: 465 hospitalized horses with gastrointestinal tract disease. Methods: Horses were classified as positive or negative for fecal Salmonella shedding during hospitalization by means of standard aerobic bacteriologic methods. The relationship between investigated exposure factors and fecal Salmonella shedding was examined by means of logistic regression. Results: The overall prevalence of fecal Salmonella ...
Drogemuller M, Failing K, Schnieder T, von Samson-Himmelstjerna G.This study was designed to investigate the effect of repeated treatments with increasingly high fenbendazole (FBZ) dosages on the phenotype and genotype of a benzimidazole (BZ)-resistant cyathostomin population. An experimentally infected horse was treated repeatedly with FBZ dose rates between 7.5 and 30.0 mg/kg body weight (bw) over approximately 2 years. Faecal egg counts (FECs) and larval cultures were performed weekly. A total of 45 faecal egg count reduction tests (FECRTs) were analysed, revealing a high variability during the course of experiment with a mean value in faecal egg count re...
Mealey RH, Leib SR, Pownder SL, McGuire TC.Equine infectious anemia virus (EIAV) is a lentivirus that causes persistent infection in horses. The appearance of antigenically distinct viral variants during recurrent viremic episodes is thought to be due to adaptive immune selection pressure. To test this hypothesis, we evaluated envelope SU cloned sequences from five severe combined immunodeficient (SCID) foals infected with EIAV. Within the SU hypervariable V3 region, 8.5% of the clones had amino acid changes, and 6.4% had amino acid changes within the known cytotoxic T lymphocyte (CTL) epitope Env-RW12. Of all the SU clones, only 3.1% ...
Park AW, Wood JL, Daly JM, Newton JR, Glass K, Henley W, Mumford JA, Grenfell BT.We assess the effects of strain heterology (strains that are immunologically similar but not identical) on equine influenza in a vaccinated population. Using data relating to individual animals, for both homologous and heterologous vaccinees, we estimate distributions for the latent and infectious periods, quantify the risk of becoming infected in terms of the quantity of cross-reactive antibodies to a key surface protein of the virus (haemagglutinin) and estimate the probability of excreting virus (i.e. becoming infectious) given that infection has occurred. The data suggest that the infectio...
Mancianti F.Feline leishmaniasis (FL) is a quite uncommon feature. Clinical disease has been described in cats since nineties begin. More than 40 reports in world literature have been referred, but the clinical cases have been only recently well defined. Most of the reports focus on infected cats living in endemic areas, even if, more recently FL due to Leishmania infantum was found in Sao Paulo State, in Brazil where autochthonous human or canine leishmaniasis cases have never reported. In Europe clinical cases of FL have been described from Portugal, France, Spain and Italy from 1996 to 2002. When a typ...
Szabó MP, Castagnolli KC, Santana DA, de Castro MB, Romano MA.Since host immune reaction to ticks interferes with tick-borne pathogen transmission, it is important to recognize naturally occurring tick-host immune relationships to better understand the epidemiology of such infectious diseases. Amblyomma cajennense is an important tick-borne disease vector in the Neotropical region and horses maintain it in domestic environments. In the present work intradermal testing of A. cajennense tick exposed horses and donkeys using crude tick antigens was used to evaluate the type of hypersensitivity induced by infestations. Animals sensitized by A. cajennense inf...
Westermann CM, Boerma S, van Nieuwstadt RA.Since the only registrated anti-ectoparasiticum for horses (foxim) is no longer available in The Netherlands, some cases of amitraz intoxication of the horse have occurred. In this article the literature concerning amitraz intoxications and experiments will be discussed and some cases will be described.
Traversa D, Giangaspero A, Galli P, Paoletti B, Otranto D, Gasser RB.Gastric or cutaneous habronemosis caused by Habronema microstoma Creplin, 1849 and Habronema muscae Carter, 1865 is a parasitic disease of equids transmitted by muscid flies. There is a paucity of information on the epidemiology of this disease, which is mainly due to limitations with diagnosis in the live animal and with the identification of the parasites in the intermediate hosts. To overcome such limitations, a molecular approach, based on the use of genetic markers in the second internal transcribed spacer (ITS-2) of ribosomal DNA, was established for the two species of Habronema. Charact...
Hall RA, Khromykh AA.West Nile virus (WNV) is a mosquito-borne flavivirus that is emerging as a global pathogen. In the last decade, virulent strains of the virus have been associated with significant outbreaks of human and animal disease in Europe, the Middle East and North America. Efforts to develop human and veterinary vaccines have taken both traditional and novel approaches. A formalin-inactivated whole virus vaccine has been approved for use in horses. DNA vaccines coding for the structural WNV proteins have also been assessed for veterinary use and have been found to be protective in mice, horses and birds...
Ciaramella P, Corona M, Cortese L, Piantedosi D, Santoro D, Di Loria A, Rigato R.One hundred and fifty horses from Italy were tested for serum antibodies to Neospora caninum by indirect fluorescence antibody test (IFAT). Antibodies were present in 42 horses (28%). The positive titres were: 1:50 (16/150-10.5%), 1:100 (26/150-17%), 1:200 (8/150-5.3%) and 1:800 (1/150-0.6%). No neurological anomalies were observed in the seropositive horses. This is the first serologic survey for Neospora spp. antibodies performed on horses born and raised in Italy.
Pinchbeck GL, Clegg PD, Proudman CJ, Morgan KL, French NP.A concurrent case-control study of 12 UK racecourses was made between March 1, 2000, and August 31, 2001, to identify and quantify the factors associated with the risk of horses falling in steeplechase races. Cases were defined as a jumping effort at a steeplechase fence that resulted in a fall and controls were defined as a successful jumping effort over any steeplechase fence at any of the 12 racecourses within 14 days before or after the case fall. Information on the horse, the jockey and the race were collected and all the fences on all the courses were surveyed. Conditional logistic regre...
Nagore D, García-Sanmartín J, García-Pérez AL, Juste RA, Hurtado A.Specific oligonucleotide probes were designed to develop a new and highly sensitive reverse line blot assay to detect and identify simultaneously different Theileria and Babesia species in horses. The amplified hypervariable V4 region of the 18S rRNA gene was hybridised against different generic and species-specific probes. The survey was conducted over 243 samples of equine blood divided into three different groups: group 1, 24 horses presented as possible clinical piroplasmosis; group 2, 181 clinically healthy free-ranging horses exposed to ticks; group 3, 38 riding horses with unrelated pat...
Durand JP, Simon F, Tolou H.West Nile virus (WNV) is a common arbovirosis, transmitted by mosquitoes mainly Culex. WNV is commonly responsible for equine epizootics and epidemics in humans in sub-Saharan Africa. It has been occasionally described in Southern Europe and in some Mediterranean countries. Since 1994, WNV clinical aspects seem to change with an increase of central neurological involvement and a higher mortality, especially among people older than 50 years. In 1999, WNV reached New York, being responsible for severe clinical manifestations. It spread all over North America in less than four years Four (only fo...
Pinchbeck GL, Clegg PD, Proudman CJ, Morgan KL, French NR.Falls during racing present a risk of injury to both horse and jockey and a risk of fatality to horses. Objective: To use video recordings of races to describe the circumstances surrounding horse falls at hurdle and steeplechase fences and to identify and quantify within-race risk factors for horse falls in National Hunt racing in the UK. Methods: A retrospective, matched, nested case-control study using video recordings of races was conducted on 6 UK racecourses. Cases and controls were matched on both race type and jump number at which the fall occurred. Conditional logistic regression analy...
Smith LJ, Marr CM, Payne RJ, Stoneham SJ, Reid SW.Septic arthritis is a serious problem in the neonate, with a poor prognosis being reported for recovery. The impact of neonatal septic arthritis on the likelihood that Thoroughbred (TB) foals will start on a racecourse is not known. Objective: The development of septic arthritis in a TB foal significantly reduces the likelihood that it will race when compared to foals from the same dam. Methods: Medical records of 69 foals treated for septic arthritis were reviewed. The dam's foaling records were reviewed and lifetime racing records were then retrieved for both the affected foals and at least ...
Hopper BJ, Steel C, Richardson JL, Alexander GR, Robertson ID.Sclerosis of the third carpal bone is a common radiographic finding in both lame and sound racehorses, but there are no guidelines correlating degree of sclerosis and incidence of lameness. Objective: To develop a protocol for describing subchondral bone sclerosis in C3 on dorsoproximal-dorsodistal oblique (DPr-DDiO) radiographs of the carpus and to correlate these changes with exercise history and carpal lameness. Methods: One hundred and six Standardbreds entering their first year of training (exercise group) and 7 age-matched Standardbreds at pasture (controls) were examined at approximatel...
Minke JM, Audonnet JC, Fischer L.The increasing international movement of horses combined with the relaxation of veterinary regulations has resulted in an increased incidence of equine infectious diseases. Vaccination, along with management measures, has become the primary method for the effective control of these diseases. Traditionally modified live and inactivated vaccines have been used and these vaccines have proven to be very successful in preventing disease. However, there are a number of equine infectious diseases for which conventional technology has shown its limitations. The advent of recombinant technology has sti...
Ward MP, Levy M, Thacker HL, Ash M, Norman SK, Moore GE, Webb PW.To describe an outbreak of encephalomyelitis caused by West Nile virus (WNV) in horses in northern Indiana. Methods: Case series. Methods: 170 horses. Methods: Horses with clinical signs suggestive of encephalomyelitis caused by WNV were examined. Date, age, sex, breed, and survival status were recorded. Serum samples were tested for anti-WNV antibodies, and virus isolation was attempted from samples of brain tissue. Climate data from local weather recording stations were collected. An epidemic curve was constructed, and case fatality rate was calculated. Results: The most common clinical sign...
Castillo-Olivares J, Wood J.West Nile virus (WNV) is a flavivirus closely related to Japanese encephalitis and St. Louis encephalitis viruses that is primarily maintained in nature by transmission cycles between mosquitoes and birds. Occasionally, WNV infects and causes disease in other vertebrates, including humans and horses. West Nile virus has re-emerged as an important pathogen as several recent outbreaks of encephalomyelitis have been reported from different parts of Europe in addition to the large epidemic that has swept across North America. This review summarises the main features of WNV infection in the horse, ...
Daly JM, Newton JR, Mumford JA.Influenza A viruses of the H3N8 subtype are a major cause of respiratory disease in horses. Subclinical infection with virus shedding can occur in vaccinated horses, particularly where there is a mismatch between the vaccine strains and the virus strains circulating in the field. Such infections contribute to the spread of the disease. Rapid diagnostic techniques are available for detection of virus antigen and can be used as an aid in control programmes. Improvements have been made to methods of standardising inactivated virus vaccines, and a direct relationship between vaccine potency measur...
Horta MC, Labruna MB, Sangioni LA, Vianna MC, Gennari SM, Galvão MA, Mafra CL, Vidotto O, Schumaker TT, Walker DH.In serum samples obtained from all the healthy humans, horses, dogs, and donkeys present on three farms in the Pedreira Municipality, an endemic area for Brazilian spotted fever, an indirect immunofluorescence assay (IFA) detected antibodies against Rickettsia rickettsii in 17 (77.3%) horses, 5 (31.3%) dogs (titers ranging from 64 to 4,048), and none of 4 donkeys or 50 humans. Five canine and eight equine sera with high antibody titers to R. rickettsii were also tested by IFA against R. bellii, R. akari, and R. africae antigens. Sera from two horses and two dogs that showed similar high antibo...
Takahashi T, Kasashima Y, Ueno Y.To determine whether race history, including the number of races and total race distance, was associated with risk of superficial digital flexor tendon (SDFT) injury in Thoroughbred racehorses in Japan. Methods: Matched case-control study. Methods: 515 Thoroughbred racehorses (case horses) that sustained an SDFT injury during training or racing in Japan during 2002 and 951 horses (control horses) without SDFT injury that were matched with case horses on the basis of age and month of the latest race. Methods: Variables related to race history were compared between case and control horses by mea...
Leroux C, Cadoré JL, Montelaro RC.Equine Infectious Anemia Virus (EIAV) is a lentivirus, of the Retrovirus family, with an almost worldwide distribution, infecting equids. It causes a persistent infection characterized by recurring febrile episodes associating viremia, fever, thrombocytopenia, and wasting symptoms. The disease is experimentally reproducible by inoculation of Shetland ponies or horses with EIAV pathogenic strains. Among lentiviruses, EIAV is unique in that, despite a rapid virus replication and antigenic variation, most animals progress from a chronic stage characterized by recurring peaks of viremia and fever ...
Singh BR, Singh VP, Agarwal M, Sharma G, Chandra M.Haemolysin patterns of 175 strains of different Salmonella enterica subspecies enterica serovars isolated from different animal sources and places were determined using 11 different blood agar media made with either non-washed horse/sheep erythrocytes or with washed erythrocytes of cattle, sheep, horse, goat, rabbit, guinea pig, and human A, O and B blood groups. Study on 47 strains belonging to 10 serovars of Salmonella from buffalo meat (buffen), 42 strains of 11 serovars from goat meat (chevon): 16 strains of Salmonella enterica serovar Paratyphi B and 25 of S. enterica serovar Paratyphi B ...
Hulínská D, Langrová K, Pejcoch M, Pavlásek I.The aim of this study was to detect Anaplasma phagocytophilum in wild and domesticated animals and to identify the phylogenetic relationships of different strains of this bacterium. We adapted six published conventional methods targeting 16S fragments for real-time polymerase chain reaction. Initial screening of samples from 419 animals found 37 Anaplasma positives, later confirmed with several different primers and a TaqMan probe. We also performed DNA quantification and melting curve analysis. The nucleic acid of Anaplasma sp. was detected in a higher percentage of cases in members of the de...
Bauer SM, Santschi EM, Fialkowski J, Clayton MK, Proctor RA.To quantify the adhesion of Staphylococcus aureus to 4 equine bone surfaces passivated in a balanced polyionic solution (Plasmalyte) or hyperimmune equine plasma (Polymune plasma). Methods: In vitro comparative study. Methods: Third metacarpal bone (MC3) surface explants from 9 equine cadavers. Methods: Approximately 1 cm(2) sections of periosteum were removed from MC3 and stapled to sterile stainless steel screens. Three bone surface explants were cut using a surgical saw to present 1 cm(2) surfaces of subperiosteal bone, cut cortical bone, or endosteum. Duplicate explants of each surface wer...
Cêtre-Sossah C, Baldet T, Delécolle JC, Mathieu B, Perrin A, Grillet C, Albina E.Bluetongue (BT) and African Horse Sickness (AHS) are infectious arthropod-borne viral diseases affecting ruminants and horses, respectively. Culicoides imicola Kieffer, 1913, a biting midge, is the principal vector of these livestock diseases in Africa and Europe. Recently bluetongue disease has re-emerged in the Mediterranean Basin and has had a devastating effect on the sheep industry in Italy and on the islands of Sicily, Sardinia, Corsica and the Balearics, but fortunately, has not penetrated onto mainland France and Spain. To survey for the presence of C. imicola, an extensive light-trap ...
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...
Hamir AN, Moser G, Rupprecht CE.A retrospective study of horses necropsied between 1985 and 1989 at a diagnostic laboratory of a veterinary school in North America is documented. In this investigation over 20 per cent of the horses had clinical neurological signs. Equine protozoal myeloencephalitis (caused by Sarcocystis neurona) and cervical stenotic myelopathy (wobbler syndrome) were the most common of these disorders. The veterinary school is located in the midst of a raccoon rabies enzootic area. However, only four cases of equine rabies were diagnosed during the 5-year study. The gross microscopical and immunohistochemi...
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 ...
Vallance SA, Spriet M, Stover SM.To enhance understanding of the nature and pathogenesis of scapular fractures in racehorses. Objective: Scapular fractures in racehorses have a consistent configuration related to sites of pre-existing stress modelling and remodelling. Methods: Fractured and intact scapulae collected post mortem were examined visually and with computed tomography (CT). Scapular fracture configuration, bone modelling changes and standardised CT morphometry and density measurements were recorded. Statistical comparisons were made between fractured, nonfractured contralateral and control scapulae. Results: Thirty...
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 ...
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...
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...
Wobeser BK.During a widespread anthrax outbreak in Canada, miniature horses were vaccinated using a live spore anthrax vaccine. Several of these horses died from an apparent immune-mediated vasculitis temporally associated with this vaccination. During the course of the outbreak, other miniature horses from different regions with a similar vaccination history, clinical signs, and necropsy findings were found. Vaccin contre l’anthrax associé à la mort de chevaux miniatures. Durant une vaste éclosion d’anthrax au Canada, des chevaux miniatures ont été vaccinés en utilisant un vaccin à base de sp...
Palfi V, Christensen LS.Twenty-five strains of equine herpesvirus 1 (EHV-1) and one strain of equine herpesvirus 4 (EHV-4) isolated from material from various clinical cases in Denmark, together with reference EHV-1 and EHV-4 strains, were compared by restriction fragment pattern (RFP) analysis and inoculation of baby mice. The RFP analyses revealed that all EHV-1 strains belonged to genome type Ip. Four fetal isolates exhibited genomic characteristics that have been suggested as specific markers of the attenuated strain Rac H, widely used as a live vaccine. As the use of five vaccines against EHV-1 and EHV-4 has nev...
Kitai Y, Shirafuji H, Kanehira K, Kamio T, Kondo T, Konishi E.West Nile virus (WNV) and Japanese encephalitis (JE) virus are distributed separately in the world with some exceptions. There is a concern that WNV may invade into Asia where JE virus exists. On and after such invasion, any differential diagnosis could be complicated by serological crossreactivities. We previously demonstrated experimentally using horses infected with WNV that preimmunization with inactivated JE vaccine considerably affected the ability of neutralization tests and immunoglobulin M (IgM) antibody-capture enzyme-linked immunosorbent assay (ELISA) to diagnose WNV infection. Here...
Leegaard J, Roth A.Case history, skin tests and RAST were compared in a group (n = 40) of children with a history suggesting allergy to horses and in a group (n = 43) in whom there was no suspicion of hypersensitivity to horses. There was an agreement of 91% between case history and prick test. The same magnitude of agreement was found between case history and RAST (89%), and the agreement between RAST and prick test was 90%. The results of this investigation are clearly in contrast to earlier earlier reports, in that there was a very good correlation between prick test, RAST and case history. The results sugges...
Botha CJ, Naudé TW.Well-known plant poisonings such as 'dunsiekte' (seneciosis) and 'jaagsiekte' (crotalariosis) of horses in southern Africa are briefly reviewed. Relatively unfamiliar mycotoxicoses such as stachybotryotoxicosis and perennial rye grass staggers and potentially occurring exotic intoxications such as equine nigropallidal encephalomalacia and ergot alkaloid poisoning are also discussed. This article is aimed at informing the southern African equine practitioner about probable poisonings that might occur locally in horses.
Ameni G, Messele Kebede A, Zewude A, Girma Abdulla M, Asfaw R, Gobena MM, Kyalo M, Stomeo F, Gumi B, Sori T.Equine histoplasmosis commonly known as epizootic lymphangitis (EL) is a neglected granulomatous disease of equine that is endemic to Ethiopia. It is caused by variety , a dimorphic fungus that is closely related to variety c The objective of this study was to undertake a phylogenetic analysis of isolated from EL cases of horses in central Ethiopia and evaluate their relationship with isolates in other countries and/or clades using the internal transcribed spacer (ITS) region of rRNA genes. Clinical and mycological examinations, DNA extraction, polymerase chain reaction (PCR), Sanger seque...
Zweygarth E, Lopez-Rebollar LM, Meyer P.Twenty blood samples of zebras (Equus zebra zebra) from the Karoo National Park and the Bontebok National Park in South Africa, all seropositive for Theileria equi, were subjected to in vitro culture to identify carrier animals and to isolate the parasites. Sixteen animals had a detectable parasitaemia in Giemsa-stained blood smears examined before culture initiation, the remaining four animals were identified as T. equi carriers by in vitro culture. Cultures were initiated either in an oxygen-reduced gas mixture or in a 5% CO2-in-air atmosphere. Out of the 20 blood samples, 12 cultures of T. ...
Tamura N, Kodaira K, Yoshihara E, Mae N, Yamazaki Y, Mita H, Kuroda T, Fukuda K, Tomita A, Kasashima Y.A retrospective cohort study was conducted to investigate risk factors for the failure of Thoroughbred racehorses to return to racing after an injury of the superficial digital flexor tendon (SDFT). Successful return was defined as the completion of five or more races after SDFT injury. The official Japan Racing Association (JRA) medical records of racehorses with a core-type SDFT injury were reviewed for clinical variables related to the characteristics of the horse and the severity of SDFT injuries at the time of diagnosis. Data on racing outcomes were obtained from the official JRA racing d...
Aufox EE, Frank LA, May ER, Kania SA.Dermatophilus congolensis is a facultative anaerobic actinomycete that causes papular to exudative dermatitis with crusting in horses. This organism is frequently implicated as a cause of pastern dermatitis, but few data are available validating the organism's association with this disease. Objective: The aim of this study was to evaluate if D. congolensis is associated with pastern dermatitis in horses utilizing RT-qPCR. Methods: Fifteen client-owned horses diagnosed with pastern dermatitis and eight client-owned unaffected control horses were utilized for this study. Methods: A cross-sectio...
Elsheikha HM, Mansfield LS.Sarcocystis neurona has become recognized as the major causative agent of equine protozoal myeloencephalitis (EPM) in the Americas. At least 3 pathogenic species of Sarcocystis, including S. neurona, can be isolated from opossums. Methods are needed to ascertain whether these isolates are viable and capable of causing infections. In this study, the nuclear stain propidium iodide (PI) was used to differentiate between live (viable) and heat-killed (nonviable) S. neurona sporocysts. PI was excluded by live sporocysts but penetrated compromised sporocyst membrane and stained sporozoite nuclei of ...
Mellish MA, Lucas ZN, Puchalski SM, Kusch TA.Laminitis is a painful condition that causes lameness in horses. However, monitoring this condition in feral horses is logistically difficult. Laminitis can be detected postmortem, as inflammation of the sensitive laminae of the hoof changes the relative location of the bony structures within the hoof capsule. Thus, evaluation of cadavers may be used to estimate laminitis prevalence in feral populations of horses. The objective of this study was to estimate the prevalence of laminitis in feral horses inhabiting the Sable Island National Park Reserve, Canada, using radiographic imagery on the h...
Rizvi SM, Slater JD, Wolfinger U, Borchers K, Field HJ, Slade AJ.The distribution of equine herpesvirus 2 (EHV-2) DNA within neurological and lymphoid tissues from 12 EHV-2 seropositive Welsh mountain ponies was determined by PCR. The lymphoid sites sampled in this study were almost universally PCR positive, thus confirming the existing virus co-cultivation data which suggest that the lymph nodes draining the respiratory tract are the main reservoirs of EHV-2 DNA. In addition, EHV-2 DNA was also detected, albeit with lower frequency, within both the peripheral and central nervous systems (PNS and CNS) of these animals. Of the CNS sites sampled 11% were PCR-...
Sharav T, Konnai S, Ochirkhuu N, Ts EO, Mekata H, Sakoda Y, Umemura T, Murata S, Chultemdorj T, Ohashi K.The genetic characterization and actual prevalence of EIAV in Mongolian horse in the disease endemic region is currently unknown. Here, 11 of 776 horse serum samples from four Mongolian provinces tested positive on agar gel immunodiffusion test. Genomic DNA extracted from all seropositive samples was subjected to nested PCR assay. Among these, three samples tested positive with nested PCR assay and were identified by sequencing analysis based on long termination repeat and tat gene of the virus. Two of the three sequences were identical, with 94.0% identity with the third. These two independen...
Özçelik R, Graubner C, Remy-Wohlfender F, Dürr S, Faverjon C.Equine health is important in regard to trade, economy, society, and the veterinary, as well as public health. To reduce the burden of equine infectious diseases internationally, it is important to collect, review, and distribute equine health surveillance data as accurate and timely as possible. Within this study, we aimed at providing a comprehensive descriptive analysis of data submitted to Equinella, a voluntary veterinary-based surveillance system of non-notifiable equine infectious diseases and clinical signs, in Switzerland. This was achieved by reviewing the reports submitted since its...
Oladunni FS, Sarkar S, Reedy S, Balasuriya UBR, Horohov DW, Chambers TM.Equine herpesvirus-1 (EHV-1) infection is an important and highly prevalent disease in equine populations worldwide. Previously we have demonstrated that a neuropathogenic strain of EHV-1, T953, suppresses the host cell's antiviral type-I interferon (IFN) response in vitro. Whether or not this is unique to EHV-1 strains possessing the neuropathogenic genotype has been undetermined. Here, we examined whether there is any direct relationship between neuropathogenic genotype and the induced IFN-β response in equine endothelial cells (EECs) infected with 10 different strains of EHV-1. The extent ...
Sharma S, Davies Morel MC, Dhaliwal GS.Decreased reproductive performance due to summer stress is a well known phenomenon in farm livestock. Whether this occurs in the mare and specifically how this might affect postpartum reproductive activity and performance, especially at Foal Heat (FH), is unknown. This study, therefore, aims to investigate this and the factors that might affect postpartum reproductive activity. Reproductive records of 228 Thoroughbred mares (694 mare years) bred in subtropical north-western India were retrospectively analysed. Overt oestrous activity occurred within 21 d postpartum in 92.94% (645/694) of mares...
Meister TL, Arroyo LG, Shanahan R, Papapetrou MA, Reinecke B, Brüggemann Y, Todt D, Stang A, Hazlett M, Baird JD, Steinmann E.Theiler's disease (TD) is a (sub-)acute hepatitis in adult horses and one of the most common causes of acute hepatic failure. Recent findings indicate that equine parvovirus hepatitis (EqPV-H) likely causes TD and that its transmission occurs via iatrogenic and/or natural routes. Following the death of an EqPV-H positive mare with TD, close-contact mares and foals in the same paddock were monitored to evaluate if there was any evidence of EqPV-H. For this purpose, the serum of close contact horses was examined 6 and 42 days after the mare's death for the presence of EqPV-H DNA and changes in l...
Scholtzek AD, Hanke D, Eichhorn I, Walther B, Lübke-Becker A, van Duijkeren E, Köck R, Schwarz S, Feßler AT.Based on antimicrobial susceptibility testing (AST), correct classifications as susceptible, intermediate or resistant are challenging for some antimicrobial agent-bacterial species combinations. In this study, we investigated 19 equine Staphylococcus aureus isolates for their susceptibility to the combination sulfamethoxazole/trimethoprim (SXT) by using broth microdilution (BMD), agar disk diffusion (DD) and automated test systems. To elucidate the presence of the corresponding genetic resistance properties among the isolates, whole genome sequence analysis was performed and the genomes were ...
Ozaki H, Shimizu-Nei A, Sugita S, Sugiura T, Imagawa H, Kida H.To provide information on the antigenic variation of the hemagglutinins (HA) among equine H 3 influenza viruses, 26 strains isolated from horses in different areas in the world during the 1963-1996 period were analyzed using a panel of monoclonal antibodies recognizing at least 7 distinct epitopes on the H 3 HA molecule of the prototype strain A/equine/Miami/1/63 (H 3 N 8). The reactivity patterns of the virus strains with the panel indicate that antigenic drift of the HA has occurred with the year of isolation, but less extensively than that of human H 3 N 2 influenza virus isolates, and diff...
Saville WJ, Morley PS, Reed SM, Granstrom DE, Kohn CW, Hinchcliff KW, Wittum TE.To investigate risk factors for use in predicting clinical improvement and survival of horses with equine protozoal myeloencephalitis (EPM). Methods: Longitudinal epidemiologic study. Methods: 251 horses with EPM. Methods: Between 1992 and 1995, 251 horses with EPM were admitted to our facility. A diagnosis of EPM was made on the basis of neurologic abnormalities and detection of antibody to Sarcocystis neurona or S neurona DNA in CSF. Data were obtained from hospital records and through telephone follow-up interviews. Factors associated with clinical improvement and survival were analyzed, us...
Thompson K, Taylor J, Mendez D, Chicken C, Carrick J, Durrheim DN.There are almost 9,500 full-time employees in Australia's thoroughbred horse breeding industry. During foaling, they can be exposed to bodily fluids and mucous membranes which may present risks for zoonotic disease. These risks can be mitigated through personal biosecurity strategies. The aim of this study was to identify which personal biosecurity strategies were more or less likely to be adopted by workers. Seventeen participants representing 14 thoroughbred breeding farms and three equine veterinary practices in Australia's largest thoroughbred breeding region trialed up to 16 stakeholder-n...
