Pathogens are microorganisms, such as bacteria, viruses, fungi, and parasites, that can cause disease in horses. These microorganisms interact with the equine immune system, often leading to a range of health issues that can affect individual horses or entire populations. Pathogens can be transmitted through various routes, including direct contact, vectors, or environmental exposure. Common equine pathogens include Streptococcus equi, Equine Herpesvirus, and Strongylus vulgaris. Understanding the interactions between equine hosts and pathogens is essential for disease prevention, management, and treatment. This page compiles peer-reviewed research studies and scholarly articles that explore the identification, transmission, and impact of pathogens on equine health.
Messick JB, Rikihisa Y.The effects of equine antiserum, immunoglobulin G (IgG) specific for Ehrlichia risticii, and its Fab fragment on E. risticii binding to, internalization into, and proliferation in P388D1 cells were studied by immunofluorescence flow cytometry. Anti-E. risticii equine serum or IgG inhibited E. risticii at a stage beyond binding and internalization. In contrast, monovalent anti-E. risticii equine Fab fragments inhibited E. risticii binding and internalization into P388D1 cells. In the presence of control equine serum, IgG, or its Fab fragment, E. risticii cells were bound, were internalized and ...
Tantaoui-Elaraki A, Mekouar SL, el Hamidi M, Senhaji M.From 10 moldy straw samples collected in a Moroccan area with an apparent equine stachybotryotoxicosis outbreak in November 1991, 8 isolates of Stachybotrys atra were obtained. They all showed toxigenesis, however they were variable in nature and intensity. While 1 isolate had only mild toxicity when fed to mice as moldy barley, another revealed very high toxicity to Artemia saline larvae, or rat skin, and to mice. The toxicity of the other 6 isolates were between these 2 limits. This study indicates that the November 1991 outbreak was due to toxigenic strains of Stachybotrys atra.
Jang SS, Hirsh DC.During the years from 1984 through 1991, 1,067 specimens from canine, equine, exotic, feline, porcine, and ruminant animal sources were found to contain members of the genus Fusobacterium: The most common sites or conditions from which members of this genus were isolated were abscesses, the respiratory tract, and pleural and peritoneal cavities. Most specimens contained a single Fusobacterium species. The most commonly isolated species was Fusobacterium necrophorum. Almost all of the specimens contained other obligate anaerobes together with facultative and obligate aerobes. The identities of ...
Shams Eldin HE, Kirchhoff H.Tracheal swabs were taken from 25 horses with respiratory diseases and investigated for mycoplasmas using three different media. Mycoplasmas could be isolated from 5 horses. The isolates were characterized by serological and biochemical methods. Four isolates could be identified as Mycoplasma equirhinis. The fifth isolate could not be typed. It did not react with antisera against mycoplasmas found in the respiratory tract of horses and its biochemical characteristics were different from the mycoplasmas described so far. It may represent a new species.
Peters SE, Wakefield AE, Whitwell KE, Hopkin JM.Genetically distinct forms of Pneumocystis carinii infect several mammalian hosts. We report the amplification of P. carinii DNA from samples of two infected thoroughbred foal lungs by using primers designed from the sequence of a P. carinii mitochondrial rRNA gene; these primers also prime the amplification of P. carinii DNA from other hosts. The nucleotide sequence of part of the mitochondrial rRNA gene amplified from P. carinii infecting one of the foals was determined and found to be distinct from that of published rat-, rabbit-, ferret-, and human-derived P. carinii sequences.
Scherbarth R, Pózvári M, Heilkenbrinker T, Mumme J.From 1972 to 1991, presecretion on an average of 183 stallions per year had been examined. Facultatively pathogenic germs were ascertained in 13.5% of the samples. However, the portion showed considerable annual fluctuation, as did the percentage of the different kinds of germs. In most of the cases, only minimal growth had been observed in culture. Except for the total percentage, these results are contradictory to those we found during the examination of cervical swabs of mares. In order to ascertain the importance of the respective results and to render possible a correct interpretation, th...
Agius CT, Studdert MJ.This chapter describes the molecular and biological properties of equine herpesviruses (EHV)2 and EHV5. It highlights advances in the study of EHV2 and EHV5. The reclassification of EHV2 and EHV5 as gammaherpesviruses rather than betaherpesviruses has profound implications for future approaches to the study of the two equine herpesviruses. The chapter places emphasis on a comparison between the properties of EHV2 and EHV5 and those of other gammaherpesviruses, especially Epstein-Barr virus (EBV), which is the causative agent of infectious mononucleosis/glandular fever in humans. Studies of the...
Hoffman AM, Viel L, Staempfli HR, Muckle CA, Yager JA.One indication for referral of horses to veterinary hospitals is for diagnosis of the microbiologic cause of pneumonia, particularly when the initial treatment fails. Although endoscopic methods have long been available for microbiologic sample collection, accuracy of these methods under these conditions have not been studied in detail. We compared the bacteria isolated from samples obtained by bronchoalveolar lavage (BAL) with those obtained by protected catheter brush (PCB) from foals with unilateral pneumonia induced by inoculation with Klebsiella pneumoniae. As part of previously described...
Hoffman AM, Viel L, Prescott JF.Despite the high incidence of distal respiratory tract infection of undetermined cause on farms, to our knowledge, the microbiologic effects of conventional antimicrobial treatment for this condition have not been studied. We evaluated the possible pathogenic role of bacterial isolates from the distal airways of foals with clinical respiratory tract disease, by correlating changes in their numbers (increase or decrease) with clinical, endoscopic, and pulmonary cytologic signs of disease resolution during treatment with antimicrobial drugs. We also determined qualitative changes in in vitro ant...
Burrows GE, Morton RJ, Fales WH.Gram-negative bacterial isolates (635) obtained from routine submissions to the Oklahoma Animal Disease Diagnostic Laboratory during 1983-1987 were tested for antimicrobial susceptibility. Minimal inhibitory concentrations (MICs) were determined for the following antimicrobials using commercially prepared microdilution assay materials: ampicillin, cephalothin, chloramphenicol, erythromycin, gentamicin, kanamycin, oxytetracycline, penicillin G, spectinomycin, sulfachlorpyridazine, sulfadimethoxine, and tylosin. Results for isolates from cattle, dogs, horses, and pigs are presented. In only a fe...
Gerdes GH, Pieterse LM.Virus was isolated from the blood of horses (n = 5) showing fever and jaundice and was identified as equine encephalosis virus. In cross neutralisation tests, the isolates were shown to belong to a new serotype related to Gamil, one of the 6 known serotypes of equine encephalosis virus. The name Potchefstroom has been proposed for this new serotype.
Enders F, Weber A.Fecal samples of 146 horses were culturally investigated for occurrence of Prototheca spp. using a selective medium, developed by PORE (1973). Prototheca zopfii could be isolated in monoculture from 9 fecal samples (6.2%). The results of this pilot study show that horses too can harbour and shed Prototheca spp. in variable frequency.
Sloet van Oldruitenborgh-Oosterbaan MM, van Duijkeren E.Salmonellosis is a worldwide problem of both men and animals. Equine salmonellosis is an increasing problem and a review of the recent knowledge is given. Etiology, symptomatology, diagnostic procedures, therapy and prevention are discussed.
Takagi M, Hoshi A, Ohta C, Shirahata T, Goto H, Urasawa T, Taniguchi K, Urasawa S.An epizootic of foal diarrhea due to serotype 3 rotavirus (RV) was observed in 89 of 168 cases (53%) during the period from March to July in 1987. A total of 51 strains of RV were isolated from the 62 diarrheal feces examined, and one isolate (CH-3) showed a unique electropherotype of viral RNA which differed from the others that widely prevailed on this farm. No positive reaction was observed between strain CH-3 and each of the antisera against serotypes 1 to 12 of human and animal RV in neutralization tests. However, dsRNAs of the CH-3 virus were hybridized with a probe prepared from a strai...
Weaver SC, Bellew LA, Gousset L, Repik PM, Scott TW, Holland JJ.We evaluated genetic and phenotypic diversity within natural populations of the alphavirus, Eastern equine encephalomyelitis (EEE) virus. RNA fingerprinting revealed that most populations within infected hosts (unpassaged isolates) contained a consensus genotype along with minority genotypes differing in one to three T1-resistant oligonucleotides. Mutation frequencies appeared to be similar to those reported for other RNA viruses, suggesting that the slow rate of EEE virus evolution is not limited by fidelity of genome replication. Within a given year, genetic diversity was generally greater a...
Wood JL, Burrell MH, Roberts CA, Chanter N, Shaw Y.The likelihood of finding evidence of inflammation in 551 tracheal washes collected endoscopically from 278 Thoroughbred racehorses increased with the number of bacterial colony forming units (cfu) per ml of wash (P < 0.001). The aerobic bacteria Streptococcus zooepidemicus, Pasteurella/Actinobacillus-like species and Streptococcus pneumoniae were significantly associated with lower airway inflammation whereas coagulase-negative Staphylococcus spp., alpha-haemolytic Streptococcus spp., Acinetobacter spp., Bacillus spp., Escherichia coli, Pseudomonas aeruginosa, non-haemolytic Streptococcus spp...
Bleumink-Pluym NM, van Dijk L, van Vliet AH, van der Giessen JW, van der Zeijst BA.The 16S ribosomal DNA sequence of Taylorella equigenitalis (formerly Haemophilus equigenitalis), the causative organism of contagious equine metritis, was determined. A phylogenetic analysis of this sequence revealed a phylogenetic position of T. equigenitalis in the beta subclass of the class Proteobacteria apart from the position of Haemophilus influenzae, which belongs to the gamma subclass of Proteobacteria. A close phylogenetic relationship among T. equigenitalis, Alcaligenes xylosoxidans, and Bordetella bronchiseptica was detected; Spirillum volutans and Chromobacterium fluviatile (Iodob...
Couto MA, Harwig SS, Lehrer RI.Equine neutrophil antimicrobial peptide 2 (eNAP-2), a recently described antimicrobial peptide isolated from equine neutrophils, was found to selectively inactivate microbial serine proteases (subtilisin A and proteinase K) without inhibiting mammalian serine proteases (human neutrophil elastase, human cathepsin G, and bovine pancreatic trypsin). Although the primary structure of eNAP-2 resembled that of several known antiproteases that belong to the 4-disulfide core peptide family, this pattern of selectivity is unique. eNAP-2 formed a noncovalent complex with native subtilisin A or proteinas...
Hirsh DC, Kirkham C, Wilson WD.Fifteen isolates of Escherichia coli obtained from the blood and tissues of septic foals had plasmid DNA of size ranging from 2.5 to 93 megadaltons. These isolates grew in normal equine serum (serum resistant), a trait previously documented to be expressed by isolates obtained from blood and tissues of septic foals, but not by isolates obtained from the feces of clinically normal horses. Of these isolates, 3 contained conjugal plasmids that encoded resistance to multiple antimicrobial agents linked to serum resistance and, in 1 isolate, to production of aerobactin as well. Serum resistance and...
Gupta AK, Yadav MP, Uppal PK, Mumford JA, Binns MM.Two A/Equi-2 (H3N8) isolates were obtained during the 1987 Indian equine influenza epizootic. The sequence of the Ludhiana/87 HA1 gene revealed that this isolate was very similar to recent European and North American isolates of equine influenza. In contrast, the Bhiwani/87 HA1 gene was nearly identical to the Miami/63 prototype H3 sequence. These results support the antigenic analysis previously carried out on these isolates using monoclonal antibodies. However, the finding that Bhiwani/87 is so similar to Miami/63, coupled with the finding that equine H3N8 influenza viruses have previously b...
Pearson GR, Davies LW, White AL, O'Brien JK.The intestinal tracts of 20 horses, killed at a local abattoir and of unknown age, sex and previous clinical history were examined for the presence of Anoplocephala perfoliata attached to the ileo-caecal junction. Four horses had no tape-worms, nine had one to 20 tapeworms attached to the mucosa and seven had more than 100 attached to the mucosa. The histological changes of thickening, ulceration and eosinophil infiltration of the mucosa at the ileo-caecal junction were more severe when more than 100 parasites were present.
Beisel CE, Edwards JF, Dunn LL, Rice NR.Transcription of pathogenic equine infectious anemia virus (EIAV) in an acutely infected horse was examined by using the polymerase chain reaction and nucleotide sequencing. Four spliced transcripts were identified in liver tissue, in contrast to the multiplicity of alternatively spliced messages reported for in vitro-propagated human immunodeficiency virus, simian immunodeficiency virus, and, to a lesser extent, EIAV. Nucleotide sequence analysis demonstrated that three of these mRNAs encode known viral proteins: the envelope precursor, the product of the S2 open reading frame, and the regula...
Gautsch S, Beckmann G, Amtsberg G, Dieckmann M, Deegen E.100 faecal samples from clinically healthy horses of different age groups and feeding habits, 50 samples of faeces from horses suffering from enteropathy accompanied by diarrhoea and small and/or large intestine from 25 horses that had died after an intestinal disease were examined for the presence of Clostridium (Cl.) perfringens. The frequency with which Cl. perfringens was detected was 22% in clinically healthy horses, 32% in horses with diarrhoea and 52% in the dead horses. In two faecal samples from the horses with diarrhoea the microbial count of Cl. perfringens was ca. 10(6) cfu/g faece...
Hong CB, Donahue JM, Giles RC, Petrites-Murphy MB, Poonacha KB, Roberts AW, Smith BJ, Tramontin RR, Tuttle PA, Swerczek TW.Placentas from aborted, stillborn, and premature foals were examined during the 1988 and 1989 foaling seasons, and 236 of 954 (24.7%) had placentitis. Microorganisms associated with placentitis were isolated or demonstrated from 162 of 236 (68.6%) placentitis cases. Leptospira spp. and a nocardioform actinomycete were 2 important, newly emerging bacteria associated with equine placentitis. Major pathogens identified in decreasing order were Streptococcus zooepidemicus, Leptospira spp., Escherichia coli, a nocardioform actinomycete, fungi, Pseudomonas aeruginosa, Streptococcus equisimilis, Ente...
Moore RM, Schneider RK, Kowalski J, Bramlage LR, Mecklenburg LM, Kohn CW.Bacterial culture and susceptibility results were analysed from 233 horses with septic arthritis/tenosynovitis or osteomyelitis that developed after fracture repair. Antibiotics were deemed highly effective, effective or ineffective if > or = 85%, 70-84.9% or < 70% of the isolates were susceptible respectively. In total, 424 bacterial types were isolated; 386 were aerobic or facultative and 38 were anaerobic. Enterobacteriaceae (28.8%) were the most common bacterial group isolated, followed by non-beta-haemolytic streptococci (13.0%), coagulase-positive staphylococci (11.8%), beta-haemol...
Stewart HL, Engiles JB, Richardson DW, Levine DG.To describe the bactericidal and fungicidal properties of a 0.0005% chlorhexidine (CHD) solution potentiated with EDTA-Tris buffers (CHD-EDTA-Tris) and evaluate the safety of 0.0005% CHD-EDTA-Tris in the upper respiratory tract (URT) of normal horses. Methods: Clinical, prospective study. Methods: Eight healthy, skeletally mature horses. Methods: In vitro-serial dilutions of CHD-EDTA-Tris and EDTA-Tris alone were evaluated for bactericidal and fungicidal activity against Aspergillus fumigatus, Escherichia coli, Staphylococcus aureus, Streptococcus equi subspecies ssp. equi, Streptococcus equi ...
Wijesundera WS, Chandrasekharan NV, Karunanayake EH, Dharmasena SP.Two repetitive sequences (IpSdM and IpSdS) have been cloned and sequenced from the genome of Setaria digitata. When IpSdM (214 bp) and IpSdS (201 bp) were aligned, a high degree of homology (85%) was observed, indicating that they belong to the same family of repeats. IpSdM represents a complete repeating element while IpSdS consists of two partial repeating elements arranged in tandem. The elements are present in about 10 000 copies comprising 2.8% of the S. digitata genome. As a diagnostic probe IpSdM detects as little as 100 pg DNA of both S. digitata and S. labiato-papillosa. It can also d...
Ali HHM, Al-Bayati LH. is one of the most important pathogens, which causes a marked economic loss in small ruminants, in particular sheep, worldwide. This study aimed to detect the prevalence of in the sera of aborted ewes in Wasit province, Iraq, using the enzyme-linked immunosorbent assay (ELISA), followed by the investigation of the main histopathological alterations that occurred in some organs of the dead newborns. Out of 180 tested samples by ELISA, 32.22% of the evaluated animals showed positive reactions to IgG antibodies toward . Concerning the titers of the infection of seropositive ewes, there were sig...
Xu Y, Zhang X, Peng P, Liu Y, Yu M, Xie L.Equine copivirus (EqCoPV) is a newly discovered parvovirus that infects equines. Currently, it is unclear whether this virus is prevalent in China. In the present study, serum samples were collected from equines in China and were processed for EqCoPV DNA detection by PCR. The results demonstrated that EqCoPV was circulating among the sampled equines, with a low detection rate of 0.94%. The genome sequence of one Chinese EqCoPV strain, UH26, was determined and used for genetic and phylogenetic analysis. The results demonstrated that UH26 has a close genetic relationship to EqCoPV strains from t...
Richet G.P. Rayer (1795-1867) had never thoroughly published his experimental studies on the contagion of glanders. His recently un-earthed hand written papers allow us to depict his experimental approach and its results. He was not the first who transmitted glanders from a patient to horses or donkeys. But he did it systematically with glander secretions from acute and chronic cases. Whatever was the disease of the donors the transmitted forms were unpredictably either chronic or acute. His conclusion was that the two forms were two symptomatic aspects of a unique disease. Clinically dormant states we...
Al-Mashat RR, Taylor DJ.Thirty-three species of bacteria were isolated from the gastrointestinal mucosa of 23 adult horses and two foals. The bacteria isolated could be related to gross and microscopical lesions in some cases. Clostridium perfringens type A, Actinobacillus equuli, Salmonella typhimurium and Campylobacter coli biotype 1 could all be associated with gastrointestinal lesions. C jejuni biotype 1 and Aeromonas hydrophila were both recovered in this study and have been identified as causes of enteritis in horses or in other species. The case of C coli enteritis appears to be the first such report. The diff...
Sahagun-Ruiz A, Waghela SD, Holman PJ, Chieves LP, Wagner GG.A DNA probe from Babesia caballi (Bc1) was selected by antibody screening of a genomic library. The Bc1 probe hybridized specifically to B. caballi genomic DNA. A polymerase-chain-reaction-based assay for B. caballi DNA was developed from primers deduced from the probe nucleotide sequence. An amplified product of 1.6 kb was detected from as little as 500 fg B. caballi template DNA. Sensitivity increased 1000-fold when the biotin-labeled Bc1 probe was hybridized to the amplicons in a Southern blot.
Jones FS.The lower nasal mucosa and the pharynx of thirty eastern and twenty-three western horses have been examined for streptococci. Eight of the eastern horses carried non-hemolytic streptococci on the nasal mucosa. From the pharynx of six, non-hepiolytic streptococci were cultivated. The throats of eighteen contained strains of the hemolytic type. The nasal mucosa of the eastern horses failed to show hemolytic streptococci. Eight western horses carried non-hemolytic streptococci in the nasal passage; eight also harbored the hemolytic type. Twenty-two strains were isolated from the pharynx. Eleven w...
Palmer JE, Benson CE, Whitlock RH.Salmonella was isolated from 13 of 100 colicky horses admitted to a referral hospital. Seven horses were shedding the microorganism at or soon after hospital admission. A unique serotype was introduced into the hospital by a horse not shedding Salmonella at admission. It was concluded that 8 horses were infected before admission. Whether the remaining 5 horses were infected before or after admission could not be determined. Salmonella senftenberg was the most commonly isolated serotype from colicky horses and from horses with salmonellosis that were not colicky on hospital admission during the...
Padilla SL, Prieto K, Dohm DJ, Turell MJ, Klein TA, Fernández R, Watts DM, Lowen RG, Palacios GF, Pitt ML, Wiley MR, Nasar F.Venezuelan equine encephalitis virus (VEEV) is an important pathogen of medical and veterinary importance in the Americas. In this report, we present the complete genome sequences of five VEEV isolates obtained from pools of Culex (Melanoconion) gnomatos (4) or Culex (Melanoconion) pedroi (1) from Iquitos, Peru. Genetic and phylogenetic analyses showed that all five isolates grouped within the VEEV complex sister to VEEV IIIC and are members of subtype IIID. This is the first report of full-length genomic sequences of VEEV IIID.
Moyaert H, Decostere A, Pasmans F, Baele M, Ceelen L, Smits K, Ducatelle R, Haesebrouck F.A novel urease-negative Helicobacter species has been isolated from faecal samples of clinically healthy horses, but no information is available about the main sites of colonisation in the equine gastrointestinal tract nor is the pathogenic potential of this microorganism known. An experimental infection in horses was therefore carried out. Methods: Four horses were infected with H. equorum strain CCUG 52199T and subjected to euthanasia at 10 (n = 2) and 30 days (n = 2) post inoculation. A fifth animal was inoculated with phosphate buffered saline and used as control. Gastrointestinal samples ...
Phumoonna T, Barton MD, Heuzenroeder MW.The aim of this study was to evaluate the usefulness of the previously identified B-cell epitope TSLNLQKDEPNGRASDTAGQ of the VapA protein of Rhodococcus equi and its association with R. equi pneumonia. A modified peptide designated PN11-14 corresponding to the epitope was recognized by all sera from experimentally infected foals with virulent R. equi ATCC103+ containing the virulence plasmid but not by its plasmid-cured derivative ATCC103- strain. Marked levels of VapA-specific immunoglobulin (Ig)G were detected in all sera from the ATCC103+ infected foals at 2 weeks after the infection. One c...
Kalinowski M, Grądzki Z, Jarosz Ł, Adaszek Ł.Rhodococcus equi (R. hoagii) is an opportunistic pathogen commonly found in foals up to 6 months old and animal environment. The R. equi genome contains genetically stable chromosomal DNA and an 80-90 kb plasmid containing vapA gene, responsible for virulence. Most reports from around the world focus on the determination of R. equi plasmid profiles. Few studies have attempted to determine differences in nucleotide sequences between virulent strains of R. equi isolated from foals and breeding environment. The aim of the study was to perform a molecular analysis of a fragment of the chromosomal ...
Clayton YM, Fox EC.The research article aims to investigate the mycology of dental calculus (tartar) and its potential to harbor fungal organisms that could lead to ocular infections, particularly in those involved in […]
Mrzdovnik N, Babič J, Lužnik D, Žigon D, Mrzdovnik M, Tavčar-Kalcher G, Tomič V, Prescott JF, Vengust M.Several bacteria associated with chronic lung pathology use quorum sensing (QS) signaling molecules to regulate their virulence in pure cultures and poly-microbial communities. Their excessive growth and biofilm formation in the respiratory tract increase the morbidity and mortality of inflammatory airway diseases in humans, such as chronic obstructive pulmonary disease (COPD), asthma and cystic fibrosis (CF). In horses, severe equine asthma (SEA) has many parallels to these human diseases. We hypothesized that QS molecules associated with the most common biofilm-forming lung pathogens in huma...
Thornton JJ, Roberts JF, AuCoin DP, Tuanyok A.We report a presumptive case of melioidosis caused by an atypical Burkholderia pseudomallei serotype in an American quarter horse in north-central Florida, USA, through archived formalin-fixed paraffin-embedded specimens dating back to 2006. This case underscores the potential pathologic impact of emergent B. pseudomallei in the Gulf region of the United States.
Ganbaatar O, Ganzorig S, Tseren-Ochir EO, Suzuki Y, Takai S.In 2024, 90 soil samples and 11 fecal samples were collected from nine Mongolian provinces. Using NANAT selective agar, R. equi was successfully isolated from 23 soil samples (25.6%) across five provinces and from three fecal samples (27.3%) collected in two provinces. A total of 122 isolates were identified as R. equi via choE-targeted polymerase chain reaction (PCR) and subsequently screened for virulence-associated genes (vapA, vapB, and vapN) by PCR. Of these, 17 isolates tested positive for the vapA gene, while the remaining 105 isolates were negative for both vapB and vapN. Plasmid prof...
Sahu SP, Dardiri AH, Rommel FA, Pierson RE.Survival of bacteria that cause contagious equine metritis (CEM) was evaluated in Amies modified transport (AMT) medium, in AMT medium with charcoal, and in Stuart transport medium at 37, 22, 4, and -70 C. The CEM bacteria suspended in transport media survived at 22, 4, and -70 C for longer periods in AMT medium with charcoal than they did in AMT and Stuart transport media. In 1 day, the number of bacteria in exudate stored in the absence of any transport medium decreased 15-fold at 22 C and twofold at 4 C. The CEM bacteria were isolated from exudate on cotton-tipped swabs from all three trans...
Giangaspero A, Lia R, Vovlas N, Otranto D.A survey on the prevalence of Thelazia spp. in the province of Bari (Apulia region, Italy) in slaughtered native horses was conducted from June 20, 1995 to April 3, 1996. Both eyes from 409 ten-month- to 4-year-old native animals were examined. Sixty horses (14.7%) were found parasitized by Thelazia lacrymalis. Three hundred-sixty one parasite specimens (220 females, 99 males and 42 larvae) were collected with a mean count burden of 6.0-5.1 (range 1 to 20) per head. T. lacrymalis specimens were found free in the conjunctiva and behind the nictitancte, in the excretory ducts of the Harderian gl...
Morier L, Cantelar N, Soler M.Eastern Equine Encephalitis (EEE) was in Cuba before the 1940s; the virus has been isolated from horses, birds, and rodents during epizootic as well as interepizootic periods. The only isolation of Western Equine Encephalitis (WEE) virus was from a sick pigeon found in the vicinity of Havana University. Both viruses can cause human disease; the isolation of WEE virus from the centre of an urban area emphasises the need for the prompt isolation and rapid identification of these agents. The object of this work was to compare the sensitivity of a continuous cell line (XL-2) from the toad, Xenopus...
Yang J, Wang Y, Cui X, Zhang Y, Yu Z.Huge numbers of microorganisms reside in livestock faeces and constitute one of the most complex microbial ecosystems. Here, faecal microbial communities of three typical livestock in Xilingol steppe grassland, i.e. sheep, cattle, and horse, were investigated by Illumina MiSeq sequencing and quantitative real-time polymerase chain reaction (qPCR). Firmicutes and Bacteroidetes comprised the majority of bacterial communities in three livestock faeces. Sordariomycetes, Leotiomycetes, and Dothideomycetes were dominant in fungal communities, as well as Methanobacteria and Methanomicrobia were domin...
Gustafsson K, Tatz AJ, Dahan R, Britzi M, Soback S, Ahmad WA, Prince H, Kelmer G. The aim of this study was to determine the concentration of metronidazole in the distal interphalangeal joint (DIPJ) of the thoracic limb after administering metronidazole to standing horses by intravenous regional limb perfusion (IVRLP). Methods: Eleven healthy horses had a wide rubber tourniquet applied to the proximal aspect of the antebrachium for 0.5 hours and 500 mg of metronidazole diluted in physiologic saline solution to a total volume of 108 mL was administered by cephalic IVRLP. Synovial fluid samples were collected from the DIPJ before perfusion and at 0.25, 0.5, 2, 12 ...
Norton E, McCue ME.A role for a genetic contribution to equine metabolic syndrome (EMS) and pars pituitary intermedia dysfunction (PPID) has been hypothesized. Heritability estimates of EMS biochemical measurements were consistent with moderately to highly heritable traits. Further, genome-wide association analyses have identified hundreds of regions of the genome contributing to EMS and candidate variants have been identified. The genetics of PPID has not yet been proven. Continued research for the specific genetic risk factors for both EMS and PPID is crucial for gaining a better understanding of the pathophys...
Cordes V, Lüpke M, Gardemin M, Seifert H, Staszyk C.In equine dentistry periodontal diseases, especially periapical inflammation, are frequently occurring problems. Anachoresis is believed to be the most common cause for the development of such disorders. Nevertheless, there is still no substantiated explanation why settlement of pathogen microorganisms occurs in equine periodontal tissues. It is expected that excessive strains and stresses occurring in the periodontal ligament (PDL) during the horse's chewing cycle might be a predisposing factor. In this study this assumption was examined by finite element (FE) analyses on virtual 3-D models o...
Chong YC, Duffus WP, Hannant D.Peripheral blood mononuclear cells (PBMC) from an adult horse and from foals demonstrated natural killer (NK)-type cytotoxicity against a range of xenogeneic and allogeneic cell targets. The human tumour cell line, Chang liver was consistently the most susceptible. Chang liver, rabbit kidney (RK-13), equine sarcoid (ES) and embryonic equine kidney (EEK) cells were more susceptible when presented to horse PBMC than monolayer cultures. Embryonic equine lung (EEL) and murine YAC-1 cells conversely, were more susceptible in a trypsinized state. Horse PBMC demonstrated higher levels of NK-type acti...
House JK, Smith BP, Wildman TR, Carrigan MJ, Kamiya DY.To determine the prevalence of Salmonella infections in horses at necropsy. Methods: Cross-sectional prevalence survey. Methods: 102 horses. Methods: Mesenteric lymph nodes were collected from horses that were necropsied. Horses had died or were euthanatized because of severe disease or at the request of the owner. Twenty-eight of the horses were racehorses euthantized following acute catastrophic injuries on the racetrack. Mesenteric lymph nodes were submitted for Salmonella culture via direct plating of tissue specimens on MacConkey agar and by use of 4 enrichment culture techniques that use...
Bertram TA, Coignoul FL, Jensen AE.Equine neutrophils were combined with contagious equine metritis organism (CEMO) or Escherichia coli in vitro in the presence of seminal plasma, uterine flushings, or Hank's balanced salt solution (HBSS). Phagocytosis and intracellular killing were estimated by bacterial culture and light and electron microscopy. With lysed neutrophils, the numbers of colony-forming units of CEMO and E coli increased in seminal plasma and uterine flushings. Numbers of CEMO decreased in HBSS. The numbers of CEMO increased more in the presence of seminal plasma than the other media. When neutrophils were in the ...
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...
Barquero N, Chanter N, Laxton R, Wood JL, Newton JR.The objective of this study was to characterise the molecular epidemiology of Streptococcus zooepidemicus isolated from the respiratory tracts of 198 Thoroughbred racehorses based at three Newmarket training yards over a 10 month period. Typing utilised two separate PCR procedures targeting the M-like protein hypervariable and the 16S-23S RNA gene intergenic spacer regions of the bacterium. S. zooepidemicus, isolated from 23% (224/983) of study samples, comprised 24 different types of varying prevalence. The four most common types, A1HV4, A1HV2, C1HVu and D1HV1, accounted for 45% of all the ty...
