The study of diseases in horses encompasses a wide range of conditions affecting equine health, including infectious diseases, metabolic disorders, and genetic abnormalities. These diseases can impact various systems within the horse, such as respiratory, gastrointestinal, and musculoskeletal systems, and can lead to significant health challenges. Research in this area focuses on understanding the pathophysiology, diagnosis, prevention, and treatment of equine diseases. Common diseases studied include equine influenza, equine herpesvirus, and laminitis. This page provides access to peer-reviewed research studies and scholarly articles that explore the etiology, clinical presentation, and management strategies of diseases in horses, contributing to the advancement of equine veterinary medicine.
Martín-Acebes MA, Blázquez AB, de Oya NJ, Escribano-Romero E, Shi PY, Saiz JC.West Nile virus (WNV) is a worldwide distributed mosquito-borne flavivirus that naturally cycles between birds and mosquitoes, although it can infect multiple vertebrate hosts including horses and humans. This virus is responsible for recurrent epidemics of febrile illness and encephalitis, and has recently become a global concern. WNV requires to transit through intracellular acidic compartments at two different steps to complete its infectious cycle. These include fusion between the viral envelope and the membrane of endosomes during viral entry, and virus maturation in the trans-Golgi netwo...
Pirrone A, Panzani S, Govoni N, Castagnetti C, Veronesi MC.The hypothalamus-pituitary-thyroid axis has specific functions, mostly related to metabolic activities, cell differentiation, and development. To the authors' knowledge, there are no studies about thyroid hormone (TH) concentrations in foals affected by perinatal asphyxia syndrome (PAS). Hence, the aims of the study are (1) to evaluate plasma TH concentrations (T3 and T4) in healthy foals during the first 7 days of life; (2) to evaluate plasma TH concentration (T3 and T4) in critically ill foals affected by PAS during the first 7 days of hospitalization; and (3) to compare TH concentrations be...
Zabek T, Golonka P, Fornal A, Semik E.Genetic polymorphism of IHH gene were investigated in Angloarabian, Polish Coldblood and Polish Halfbred horses with the inclusion of a group of Polish Halfbreds affected by osteochondrosis. IHH is a good candidate gene for association study of developmental disorders mainly affecting skeleton development. DNA sequence spanning IHH gene annotated in the horse genome and its putative promoter were investigated using SANGER sequencing. Analysis of genetic variability at polymorphic sites in the IHH gene body and the promoter region confirmed genetic differences between warmblood and coldblood ho...
Smith MR, Wright IM.Although fractures of the proximal phalanx are one of the most common long bone fractures of Thoroughbred horses in training, limited details on variations in morphology and radiological progression have been published. Objective: To describe in detail the configuration of parasagittal fractures of the proximal phalanx in a group of Thoroughbred racehorses, to report fracture distribution within this group of horses and to document radiological progression of fracture healing in cases treated by internal fixation. Methods: Restrospective case series. Methods: Case records and radiographs of Th...
Knowles EJ, Menzies-Gow NJ, Mair TS.Plasma fructosamine concentration ([fructosamine]) is believed to reflect medium term, average blood glucose concentration and in a previous study was higher in horses with active laminitis than in normal horses. Pituitary pars intermedia dysfunction (PPID) is associated with hyperglycaemia and laminitis. Objective: To test the hypotheses that: [fructosamine] is higher in PPID cases than normal animals; furthermore, that within cases of PPID [fructosamine] is higher in those with active laminitis than nonlaminitic cases and in cases that have been affected by active laminitis in the preceding ...
Bastos RG, Suarez CE, Laughery JM, Johnson WC, Ueti MW, Knowles DP.Members of the CCp protein family have been previously described to be expressed on gametocytes of apicomplexan Plasmodium parasites. Knocking out Plasmodium CCp genes blocks the development of the parasite in the mosquito vector, making the CCp proteins potential targets for the development of a transmission-blocking vaccine. Apicomplexans Babesia bovis and Babesia bigemina are the causative agents of bovine babesiosis, and apicomplexan Theileria equi causes equine piroplasmosis. Bovine babesiosis and equine piroplasmosis are the most economically important parasite diseases that affect world...
North SE, Wakeley PR, Mayo N, Mayers J, Sawyer J.Infection with Streptococcus equi subspecies equi (S. equi) is endemic in the UK. A proportion of horses serve as long-term carriers and act as a reservoir of infection. Detection of these persistently infected horses is difficult using standard culture techniques owing to a lack of sensitivity and overgrowth by contaminating bacteria. In addition, differentiation of this causative bacterium from the closely related S. equi zooepidemicus has made the development of reliable and accurate diagnostic tests difficult. Objective: To develop and validate a sensitive and specific real-time PCR assay ...
Ishii M, Aoki T, Yamakawa K, Magata F, Gojo C, Ito K, Kayano M, Nambo Y.The aim of this study was to clarify the relationship between the placental retention time (PRT) and the reproductive performance following mating at the foal heat in Thoroughbreds. For this purpose, we interviewed 292 farmers over a period of 3 years with questionnaires evaluating foaling, expulsion of placenta and reproductive performance at the foal heat in 1,432 mares. The obtained data were later compared with a previous study of heavy draft mares. The average of the PRT of the 1,432 Thoroughbred mares was 58 ± 88 min (mean ± SD). The mean PRT of Thoroughbreds was significantly shorter ...
Wylie CE, Shaw DJ, Fordyce FM, Lilly A, McGorum BC.Equine grass sickness (EGS) remains a frequently fatal disease of equids in Britain. Since previous investigations of signalment- and meteorology-related risk factors for EGS have yielded some conflicting data, further investigation is warranted. Objective: To identify signalment- and meteorology-related risk factors for EGS in Scotland. Methods: Retrospective time-matched case-control study. Methods: This study was undertaken using data for 455 EGS cases and 910 time-matched controls that were referred to the Royal (Dick) School of Veterinary Studies, and average UK Meteorological Office weat...
Barsnick RJ, Hurcombe SD, Dembek K, Frazer ML, Slovis NM, Saville WJ, Toribio RE.Resistance to the somatotropic axis and increases in ghrelin concentrations have been documented in critically ill human patients, but limited information exists in healthy or sick foals. Objective: To investigate components of the somatotropic axis (ghrelin, growth hormone and insulin-like growth factor-1 [IGF-1]) with regard to energy metabolism (glucose and triglycerides), severity of disease and survival in critically ill equine neonates. It was hypothesised that ghrelin and growth hormone would increase and IGF-1 would decrease in proportion to severity of disease, supporting somatotropic...
Dixon PM, Ceen S, Barnett T, O'Leary JM, Parkin TD, Barakzai S.Cheek teeth diastemata are a common cause of painful periodontal disease in horses, but there is limited objective information on their treatment. Objective: To assess the long-term response to diastema widening in clinically affected horses. Methods: Retrospective study. Methods: Medical records from cases of cheek teeth diastemata treated by diastema widening referred to the University of Edinburgh Equine Hospital from 2008 to 2011 were analysed. Results: During this period, 302 horses were diagnosed with clinically significant cheek teeth diastemata, of which 202, median age 11 years, with ...
Fielding CL, Meier CA, Magdesian KG, Pusterla N.Fecal shedding of Salmonella spp. was recently documented in 8% of endurance horses presented to equine referral centers for colic. Previous studies have documented fecal shedding of Salmonella spp. in as few as 0.8% of the general horse population, although horses with colic appear to be at higher risk. Fecal Salmonella spp. shedding before and after endurance horse competitions has not been evaluated. Fecal samples were collected from 204 horses during three separate 100 mile endurance competitions. Following incubation in selenite broth, 289 fecal samples were tested by real-time PCR analys...
Aurich C, Weber J, Nagel C, Merkl M, Jude R, Wostmann S, Ollech D, Baron U, Olek S, Jansen T.Early pregnancy loss is a major reason for low reproductive efficiency in the horse. In humans and mice, low numbers of regulatory T cells (Treg cells) are linked to miscarriage. The percentage of Treg cells in oestrous mares at the start of the breeding season was evaluated in relation to the outcome of subsequent pregnancy. For identification and quantification of Treg cells, a highly sensitive and specific qPCR assay targeting the Treg-specific demethylated region in the equine forkhead box transcription factor (FOXP3) gene was established. In a total of 108 mares, pregnancy was followed un...
Belgrave RL, Dickey MM, Arheart KL, Cray C.To compare serum amyloid A (SAA) concentration, plasma fibrinogen concentration, total WBC count, and serum albumin-to-globulin concentration ratio (A:G ratio) in clinically normal (CN) and clinically abnormal (CA) horses. Methods: Prospective cohort study. Methods: 111 CN horses and 101 CA horses hospitalized at a specialty clinical practice. Methods: Shortly after admission, a blood sample (20 mL) was collected from each horse for a CBC, serum protein electrophoresis, and determination of plasma fibrinogen concentration; SAA concentration was assessed with a previously validated immunoturbid...
Steel CM, Pannirselvam RR, Anderson GA.The aims of this study were to determine the risk of septic arthritis after intra-articular medication (IAM) and to identify potential risk factors for this complication. Methods: A retrospective and prospective descriptive study of prevalence, and matched case-control study for risk factors. Results: Of 16,624 joints injected in 1103 horses at 6695 horse-visits, septic arthritis occurred as a complication in 13 joints (13 horses). The risk of septic arthritis following IAM was 7.8 cases per 10,000 injections or 1 case per 1279 injections. Veterinarian and type of corticosteroid were identifie...
Soares IR, Silva SO, Moreira FM, Prado LG, Fantini P, Maranhão Rde P, da Silva Filho JM, Melo MN, Palhares MS.This study reports the first evidence of infection by Leishmania infantum in Equus caballus in Americas and the first mixed infection of L. infantum/Leishmania braziliensis on this mammalian species in the world. The diagnoses was based on presence of parasites in lesions and bone marrow aspirates, their identification by using specific primers for L. infantum and L. braziliensis complexes and also serological methods IFAT and ELISA. The analysis of the PCR products suggested mixed infection in three animals. Further studies involving equine leishmaniasis are carrying out in order to clarify t...
Pires MS, Santos TM, Santos HA, Vilela JA, Peixoto MP, Roier EC, Silva CB, Barreira JD, Lemos ER, Massard CL.The objective of this study was to evaluate factors associated with infestation by Amblyomma cajennense on horses in two microregions of the state of Rio de Janeiro. Horses on 62 farms in the municipalities of the Itaguaí and Serrana microregions were evaluated between January and May 2009. The animals were examined to determine the presence of ticks and infestation level. The animals' rearing and management were assessed on each farm property using an epidemiological questionnaire. Out of the 635 horses evaluated, 41.6% were infested with A. cajennense. It was observed that farms in low-alti...
Vendrig JC, Coffeng LE, Fink-Gremmels J.Deficient innate and adaptive immune responses cause newborn mammals to be more susceptible to bacterial infections than adult individuals. Toll-like receptors (TLRs) are known to play a pivotal role in bacterial recognition and subsequent immune responses. Several studies have indicated that activation of certain TLRs, in particular TLR-2, can result in suppression of inflammatory pathology. In this study, we isolated peripheral blood mononuclear cells (PBMCs) from adult and newborn horses to investigate the influence of TLR-2 activation on the inflammatory response mediated by TLR-4. Data we...
Komosa M, Purzyc H, Fraackowiak H.The main aim of the study was to compare the shape of navicular bones classified as normal and pathologically changed. A comparison of metric features of the navicular bone between different types of horses and associating the examined parameters to the size of the middle and distal phalanges was an additional aspect of the study. The material comprised 53 horses of various breeds which were divided into three types. Through anatomical examinations it was concluded that as many as 30 navicular bones were normal, while 23 were found to present pathological changes. The following methods of stat...
Gómez-Sanz E, Simón C, Ortega C, Gómez P, Lozano C, Zarazaga M, Torres C.Eight coagulase-positive staphylococci from equines with different pathologies obtained between 2005 and 2011 were investigated. Isolates were characterized by different molecular techniques (spa-, agr-, MLST), and clonal relatedness of strains was investigated by ApaI and SmaI PFGE. Anti-microbial resistance and virulence profiles were determined. Six isolates were identified as Staphylococcus aureus, and two as Staphylococcus pseudintermedius. Of these, four isolates were methicillin-resistant S. aureus (MRSA) ST398 and one S. pseudintermedius was mecA positive and typed as ST68. One MRSA ...
Bordin AI, Suchodolski JS, Markel ME, Weaver KB, Steiner JM, Dowd SE, Pillai S, Cohen ND.Rhodococcus equi is an important pathogen of foals. Enteral administration of live, virulent R. equi during early life has been documented to protect against subsequent intrabronchial challenge with R. equi, indicating that enteral mucosal immunization may be protective. Evidence exists that mucosal immune responses develop against both live and inactivated micro-organisms. The extent to which live or inactivated R. equi might alter the intestinal microbiome of foals is unknown. This is an important question because the intestinal microbiome of neonates of other species is known to change over...
Gao X, Jiang CG, Wang XF, Lin YZ, Ma J, Han XE, Zhao LP, Shen RX, Xiang WH, Zhou JH.The contribution of S2 accessory gene of equine infectious anemia virus (EIAV) to the virulence of pathogenic strains was investigated in the present study by reverse mutation of all four consensus S2 mutation sites in an attenuated EIAV proviral strain, FDDV3-8, to the corresponding sequences of a highly pathogenic strain DV117. The S2 reverse-mutated recombinant strain FDDVS2r1-2-3-4 replicated with similar kinetics to FDDV3-8 in cultivated target cells. In contrast to the results of other studies of EIAV with dysfunctional S2, reverse mutation of S2 only transiently and moderately increased...
Couto N, Belas A, Tilley P, Couto I, Gama LT, Kadlec K, Schwarz S, Pomba C.The aim of this study was to evaluate the biocide and antimicrobial susceptibility of methicillin-resistant staphylococcal isolates from horses. Fourteen methicillin-resistant staphylococci (MRS) were subjected to an extensive genotype characterization, including SCCmec, dru, spa, PFGE and MLST typing. Antimicrobial susceptibility testing was performed and resistance genes were detected by PCR. Minimum bactericidal concentrations (MBCs) of four biocides [chlorhexidine acetate (CHA), benzalkonium chloride (BAC), triclosan (TCL) and glutaraldehyde (GLA)] were determined following the recommendat...
Hosseini M, Moraveji M, Tahamtan Y, Rahimian A, Mohammadi G, Namavari M.Neospora caninum, an obligate intracellular protozoan parasite, is recognized as a major cause of abortion in cattle, while limited information is presently available on the seroprevalence of Neospora antibodies in horses' worldwide. The aim of the present study was to determine serologic prevalence of Neospora infection in horses in Iran. Methods: Sera from 150 horses from Mashhad suburb in Razavi Khorasan Province, northeast Iran were examined for antibodies to Neospora spp. using Neospora modified direct agglutination test (N-MAT). Results: Antibodies to this parasite were detected in 45 (3...
Nappert G, Johnson PJ.The purpose of the present study was to investigate the acid-base status and the concentration of organic acids in horses with colic caused by various disorders. Blood samples were collected from 50 horses with colic and from 20 controls. No intravenous fluids had been given prior to sample collection. Identified causes of colic included gastric ulceration, small intestinal volvulus, cecal intussusception, cecal rupture, colonic impaction, left dorsal colon displacement, right dorsal colon displacement, colonic volvulus, colitis, peritonitis, and uterine torsion. Thirty-seven horses recovered ...
Steinbach F, Westcott DG, McGowan SL, Grierson SS, Frossard JP, Choudhury B.Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a respiratory and reproductive disease of equids, which is notifiable in some countries including the Great Britain (GB) and to the OIE. Herein, we present the case of a persistently infected stallion and the phylogenetic tracing of the virus strain isolated. Discussing EAV occurrence and phylogenetic analysis we review features, which may aid to harmonise and enhance the classification of EAV.
Jasiński T, Zdrojkowski Ł, Ferreira-Dias G, Kautz E, Juszczuk-Kubiak E, Domino M.Endometrosis is a frequently occurring disease decreasing mares' fertility. Thus, it is an important disease of the endometrium associated with epithelial and stromal cell alterations, endometrium gland degeneration and periglandular fibrosis. Multiple degenerative changes are found in uterine mucosa, the endometrium. However, their pathogenesis is not well known. It is thought that nuclear factor-κB (NF-κB), a cell metabolism regulator, and its activation pathways take part in it. The transcription of the profibrotic pathway genes of the NF-κB in fibrotic endometria differed between the fo...
Rucker A.The digital venogram uses contrast radiography to evaluate the soft tissues and vasculature of the foot, thus identifying pathology attributable to laminitis. Pathology can be detected before changes appear on plain-film radiographs. When used in conjunction with clinical and radiographic findings, information gained from a venographic study informs and directs treatment. Serial venograms assess the response to treatment and help determine prognosis early in the course of therapy. If the venographic contrast pattern does not improve, either the treatment needs to be altered, or the damage is s...
O'Callaghan MW, Goulden BE.This paper describes the distinctive radiographic changes detected in the dorso-caudal lungfields of four racing thoroughbreds recently affected by exercise-induced epistaxis. A diffuse but localized increase in density was seen in all four cases, which demonstrated a variation from a predominantly alveolar density to an interstitial pattern and finally to increased bronchial markings. Evolution of the radiographic pattern of the pulmonary densities appeared to be related to the time that had elapsed since the bleeding incident. The implications of the changing pattern and site of the densitie...
Johnson PJ, Moore LA, Mrad DR, Turk JR, Wilson DA.The sudden death of two horses was attributed to the rapid and acute development of pulmonary aspergillosis. One horse was making excellent postoperative progress after a jejunal resection and anastomosis for intestinal adhesions. The other horse was being treated routinely for equine protozoal myeloencephalitis (EPM). Signs of fever and an increased respiratory rate were detected shortly before death in the first horse, but no premonitory clinical signs characteristic of pulmonary infection were detected in the horse being treated for EPM. Both horses developed rapidly debilitating, acute pul...
Larsen AB, Moon HW, Merkal RS.The susceptibility of horses to Mycobacterium paratuberculosis was studied. A total of 8 colts was used: 2 colts were exposed intravenously and 1 colt used as a contact control was placed with them; 2 colts were exposed intragastrically; 1 colt was administered killed M. paratuberculosis intravenously; and the remaining 2 colts were used as normal controls and were housed separately. Colts administered live bacilli intravenously began losing weight 84 days after exposure, and shortly thereafter they had clinical signs of disease, consisting of loss of body weight and rough coat. The exposed co...
Murphy JM, Severin GA, Lavach JD, Hepler DI, Lueker DC.A modified Bacillus Calmette-Guerin (BCG) preparation was used successfully in the treatment of 7 cases of equine sarcoid. The BCG preparation was injected into the lesions. The longest period of remission has been 24 months, and the shortest period of remission has been 9 months, with no signs of recurrence of the tumor in any of the presented cases.
Pearson EG, Hedstrom OR, Sonn R, Wedam J.A 4-day-old foal died with bloody diarrhea. Using a mouse neutralization test, Clostridium perfringens type C was isolated from intestinal contents, and alpha and beta toxins were identified. About 4 m of the jejunum had severe necrohemorrhagic enteritis. Microscopically, large, rod-shaped, gram-positive bacteria were seen on necrotic intestinal villi by use of Brown and Hopp's stains.
Cohen ND, Heck FC, Heim B, Flad DM, Bosler EM, Cohen D.Four hundred sixty-nine serum samples were obtained from horses admitted to the internal medicine service of the Texas Veterinary Medical Center between Jan 1 and Dec 31, 1990. Serum samples were tested by ELISA for antibody to Borrelia burgdorferi. Of these 469 samples, 1 (0.2%) was repeatedly seropositive for the organism by ELISA. Confirmatory testing by protein immunoblot was negative. The observed seroprevalence was 0%; the upper bound of the 95% confidence interval was 0.6%. These findings indicate the evidence of infection with B burgdorferi is presently uncommon in horses in central Te...
Rantala M, Attia S, Koukila-Kähkölä P, de Hoog S, Anttila M, Katila T.We present an unusual equine endometritis case associated with Cladophialophora bantiana in a 15-year-old mare. The mare displayed infertility and uterine fluid accumulation with numerous black, hairy granules. Microscopically, the fluid revealed numerous septate, dark fungal hyphae and conidia in chains. Culture yielded C. bantiana (CBS 138271); the species was confirmed by internal transcribed spacer (ITS) sequencing. Treatment was unsuccessful. C. bantiana causes cerebral phaeohyphomycosis in humans, while animal cases are rare. Animal cases are reviewed.
Kite GC, Lawrence TJ, Dauncey EA.A method is described for the analysis of taxine alkaloids by liquid chromatography/mass spectrometry. It is applicable to the detection of taxine alkaloids in the stomach contents of horses in which Taxus poisoning is suspected. Analysis of a leaf extract of Taxus baccata revealed unreported alkaloids of the same relative molecular mass as taxine B and isotaxine B.
Richey MT, Holland MS, McGrath CJ, Dodman NH, Marshall DB, Court MH, Norman WM, Seeler DC.The incidence of post-anesthetic lameness in 655 horses undergoing 733 anesthetic episodes over a 3 year period was 6.4%. Nineteen factors previously reported or proposed to play a role in the development of post-anesthetic lameness were evaluated statistically. Only hypotension and the duration of the anesthetic period were significant factors.
Piza AS, Pereira AR, Terreran MT, Mozzer O, Tanuri A, Brandão PE, Richtzenhain LJ.We used a p26 recombinant protein (p26r) from equine infectious-anemia virus (EIAV) expressed in Escherichia coli as antigen to standardize an agar-gel immunodiffusion (AGIDp26r) test and an indirect ELISA (ELISAp26r) for the detection of antibodies against EIAV in 720 equine sera from Brazil. We evaluated the tests's relative diagnostic sensitivities (relSe) and relative diagnostic specificities (relSp) against a commercial AGID kit (Idexx, USA). We used three sera panels: panel A--196 AGID-negative sera from an AIE non-endemic controlled area; panel B--194 AGID-negative sera from an AIE ende...
Owen RA, Jagger DW, Quan-Taylor R.The prevalence of Anoplocephala perfoliata in 103 horses and ponies from Clwyd, Powys and the adjacent English marches, slaughtered during January 1987, was 69 per cent.
Miller FL, Bellaw JL, Lyons ET, Nielsen MK.Strongyloides westeri is a threadworm parasite found in the small intestine mainly in foals at up to about 4 months of age. This parasite is associated with small intestinal enteritis and diarrhea as well as skin irritation and a clinical syndrome called "frenzied behavior" due to percutaneous invasion. The aim of this study was to investigate S. westeri parasite burdens in age groups older than the initial lactogenic transmission phase. Secondary aims were to examine the impact of host age and gender on worm burden and egg output in naturally infected foals. Thirteen foals were enrolled in th...
McCulloch J, Williamson SA, Powis SJ, Edington N.It has been suggested that EHV-1 infection may perturb immune responsiveness in the natural equine host. The mechanism underlying this phenomenon is not clear, but disturbances of circulating leucocyte populations could contribute. In order to objectively assess the nature of the haematological changes provoked by EHV-1 infection, two groups of conventionally-maintained Welsh mountain ponies were challenge-infected intra-nasally with the Ab4 isolate of EHV-1. These groups were controlled by similarly-sized groups of non-infected ponies. All data generated was subjected to rigorous statistical ...
Habibi G, Esmaeilnia K, Hablolvarid MH, Afshari A, Zamen M, Bozorgi S.Equine piroplasmosis (EP) is the cause of persistent tick-borne infection with no symptoms, but the most important problem of EP is due to the persistent carrier state. Carrier animals to Babesia (Theileria) equi (Laveran 1901) and B. caballi (Nuttall, 1910) infestation could be identified by extremely sensitive PCR-based method. The purpose of this study was to identify the causative agents of equine piroplasmosis based on molecular and microscopic assays in equids from Kurdistan Province, Iran. Methods: Thirty one horse and mule blood samples were used with history of living in Kurdistan Pro...
Ragle CA, Meagher DM, Lacroix CA, Honnas CM.A retrospective study of 40 horses that underwent surgical treatment for sand colic was performed. Three horses were euthanatized and one died during surgery. Of the 36 horses that recovered from anesthesia, five died before discharge from the hospital and seven died after discharge. Twenty-four horses survived at least 12 months. Sand impaction of the right dorsal colon was present in 26 horses. In addition to sand impaction, 10 horses also had colonic displacement or volvulus.
Pille F, Martens A, Schouls LM, Dewulf J, Decostere A, Vogelaers D, Gasthuys F.The objectives of the present study were to evaluate the accuracy of broad range 16S rRNA gene PCR compared to bacterial culture for the detection of synovial infection in horses. The study included 57 synovial fluid samples from horses with presumed synovial infection and a control group consisting of 31 synovial fluid samples originating from clinically normal horses and horses with aseptic synovial inflammation. All samples were analysed by 16S PCR with reverse line blot (RLB) hybridisation. Synovial fluid samples were cultured using conventional agar plate methods (APM) and/or blood cultur...