Infections in horses encompass a range of diseases caused by various pathogens, including bacteria, viruses, fungi, and parasites. These infections can affect different systems within the horse, such as the respiratory, gastrointestinal, and integumentary systems, leading to a variety of clinical signs depending on the pathogen and the severity of the infection. Common infectious diseases in horses include equine influenza, strangles, and equine herpesvirus. Diagnosis often involves clinical examination, laboratory testing, and sometimes imaging, to identify the causative agent and assess the extent of the disease. Treatment strategies may include antimicrobial therapy, supportive care, and preventive measures such as vaccination and biosecurity practices. This page aggregates peer-reviewed research studies and scholarly articles that explore the pathogenesis, diagnosis, treatment, and prevention of infectious diseases in equine populations.
Vera L, Boyen F, de Visscher A, Vandenbroucke V, Vanantwerpen G, Govaere J.The use of commercial chromogenic agar plates for the rapid, easy and correct identification of equine endometritis-causing bacteria has been proposed. Preliminary tests in our lab revealed undescribed limitations. Therefore, we tested the ability of the Brilliance UTI agar, a commercially available chromogenic agar, to accurately identify bacteria causing equine endometritis. Objective: To 1) investigate whether bacteria present in the equine uterus are able to grow on this chromogenic agar plate, 2) determine whether these bacteria belong to the genera for which these agar plates were origin...
Zak A, Siwinska N, Slowikowska M, Borowicz H, Ploneczka-Janeczko K, Chorbinski P, Niedzwiedz A.Commensal bacterial and fungal flora of the conjunctival sac has been described in horses and other animals. The identification of commensal flora of the conjunctival sac may aid in the diagnosis of ocular inflammatory diseases, such as conjunctivitis or more severe ulcerative keratitis, common in horses. Moreover, damage of ocular protective barriers may lead to an opportunistic infection. The study was carried out in Silesian horses kept at a single breeding center in South-western Poland, in order to limit any breed-dependant and climate-dependant variables affecting the results. Following ...
Castro ER, Arbiza J.Infection with equid alphaherpesvirus 1 (EHV-1) causes respiratory disease, abortion and neurological disorders in horses. Molecular epidemiology studies have demonstrated that a single nucleotide polymorphism (A2254/G2254) in the genome region of open reading frame 30 which results in an amino acid variation (N752/D752) of the EHV-1 DNA polymerase, is significantly associated with the neuropathogenic potential of naturally occurring strains. In recent years, an increase in the number of cases of equine neurological disease caused by neuropathogenic variants of EHV-1 has been observed in numer...
Mucha V, Hollý J, Varečková E, Kostolanský F.Avian influenza A viruses (IAVs) are able to overcome the interspecies barrier and adapt to the new non-avian host. The process of adaptation requires the adaptive changes of IAV genome resulting in amino acid substitutions. The aim of this work was the description of amino acid substitutions in avian influenza A viruses (IAVs) occurring during their adaptation to equine host. Today, viruses of the equine influenza H3N8 subtype, first isolated in 1963, represent a single genetic lineage of IAV causing a respiratory disease in horses. We compared the amino acid sequences of the conserve...
Schein FB, Maia MO, Witter R, Marcili A, Camargo LM, Dutra V, Nakazato L, Candido SL, Almeida EM, Oliveira ACS, Pacheco RC.We evaluated the distribution of piroplasmids in equids from the Mato Grosso state in Midwestern Brazil using molecular methods and the interspecific genetic diversity. For this, 1,624 blood samples of equids from 973 farms were examined by PCR, using primer pairs that amplify a fragment of the genes rap-1 and ema-1 of Babesia caballi and Theileria equi, respectively. For molecular characterization and phylogenetic studies, 13 and 60 sequences of the rap-1 and ema-1 genes, respectively, were used to build a dendogram using maximum parsimony. B. caballi and T. equi were detected in 4.11% and 28...
Ji S, Na L, Ren H, Wang Y, Wang X.Human myxovirus resistance protein 2 (huMxB) has been shown to be a determinant type I interferon (IFN)-induced host factor involved in the inhibition of human immunodeficiency virus type 1 (HIV-1) as well as many other primate lentiviruses. This blocking occurs after the reverse transcription of viral RNA and ahead of integration into the host DNA, which is closely connected to the ability of the protein to bind the viral capsid. To date, Mx2s derived from nonprimate animals have shown no capacity for HIV-1 suppression. In this study, we examined the restrictive effect of equine Mx2 (eqMx2) o...
Ramsay JD, Evanoff R, Mealey RH.Hepacivirus A (also known as nonprimate hepacivirus and equine hepacivirus) is a hepatotropic virus that can cause both transient and persistent infections in horses. The evolution of intrahost viral populations (quasispecies) has not been studied in detail for hepacivirus A, and its roles in immune evasion and persistence are unknown. To address these knowledge gaps, we first evaluated the envelope gene (E1 and E2) diversity of two different hepacivirus A strains (WSU and CU) in longitudinal blood samples from experimentally infected adult horses, juvenile horses (foals), and foals with sever...
Ata EB, Zaghawa A, Ghazy AA, Elsify A, Abdelrahman K, Kasem S, Nayel M.Equine herpesvirus-1 (EHV-1) is an important pathogen, which infects horses worldwide with high morbidity but low mortality rates. The respiratory disorders and abortions are the most common indicators. Ab4p (an abortigenic and paralytic virus) is one of the most important and virulent strains. The development and functional characterization of the open reading frame-68 (ORF68) negative EHV-1 Ab4p mutants and an assessment of their roles in the infection at the cellular level were the main targets of the current study. Escherichia coli DH10β containing the Ab4p bacterial artificial chromosome...
Rannamäe E, Andrianov V, Järv E, Semjonov A, Haak A, Kreem J.The remains of a horse's hind foot - a third metatarsal bone and three phalanges - were found in a presumed waste pit of a prosperous medieval household in Viljandi, Estonia, dated from the second half of the 13th to the beginning of the 15th century. The metatarsal bone had been broken during the horse's lifetime and showed evidence of partial healing. Using archaeological, zooarchaeological, morphological, microscopic, densitometric and radiographic analyses, we investigated the bones and the healing process in order to understand animal treatment in a medieval urban context. Our results sho...
Scare JA, Steuer AE, Gravatte HS, Kálmán C, Ramires L, Dias de Castro LL, Norris JK, Miller F, Camargo F, Lawyer A, De Pedro P, Jolly B, Nielsen MK.Anthelmintic resistance among cyathostomin parasites is a wide-spread problem. The parasite control guidelines written by the American Association of Equine Practitioners (AAEP) encourages the preservation of anthelmintic efficacy by reducing treatment frequency, using targeted deworming, and implementing environmental management practices. While there is knowledge regarding parasite management practices of affluent horse farms in the United States, surveys rarely explore the rural and underserved regions. The purpose of this study was to observe the management practices of horse farms in rura...
van der Kolk JH, Endimiani A, Graubner C, Gerber V, Perreten V.Acinetobacter spp. are aerobic, rod-shaped, Gram-negative bacteria belonging to the Moraxellaceae family of the class Gammaproteobacteria and are considered ubiquitous organisms. Among them, Acinetobacter baumannii is the most clinically significant species with an extraordinary ability to accumulate antimicrobial resistance and to survive in the hospital environment. Recent reports indicate that A. baumannii has also evolved into a veterinary nosocomial pathogen. Although Acinetobacter spp. can be identified to species level using matrix-assisted laser desorption/ionisation time-of-flight mas...
Yang C, Weisbrode S, Yardley J, Schroeder E, Premanandan C.Ischaemia-induced physeal injury has not been described previously in the horse. A 1-month-old Quarter horse foal was submitted for necropsy examination due to an acute onset of ataxia followed by a 4-week history of progressive decline. Focal narrowing of the spinal canal due to ventral compression by the rotation of the cranial aspect of the third cervical vertebra (C3) was observed. The metaphysis and diaphysis of C3 were markedly shortened and white-tan in colour. Microscopically, there was complete loss of the dorsal compact bone of C3 and replacement of 80% of the physis that runs parall...
Santos DW, Madeira de Carvalho LM, Molento MB.Cyathostomins comprise around 50 parasite species of equids, offering a great challenge regarding their individual identification. The objective of our work was to improve identification of infective third stage larvae (L3) with a morphological key supplemented with detailed scientific illustrations based on our research and available literature. The highlighted features were; the number, arrangement, and shape of intestinal cells (IC), general features and the total body length of the eight different Cyathostomin sensu latum types (Type A, B, C, D, E, F, G, H), Gyalocephalus capitatus, and Po...
Lean NE, Ahern BJ.Mycotic rhinitis is a rare disease in horses, with few cases reported worldwide and none reported in Australia. Fungal infection of the upper respiratory tract can occur in all species, but its prevalence in horses is considerably lower than in canines or humans. The disease is linked to a variety of pathogens and the clinical signs are associated with subsequent upper respiratory tract damage. Methods: A 6-year-old Quarter Horse gelding in Queensland, Australia, was presented with chronic nasal discharge and dyspnoea following previous unsuccessful medical treatment of 9 months' duration. C...
Seeber PA, Quintard B, Sicks F, Dehnhard M, Greenwood AD, Franz M.Equine Herpesviruses (EHV) are common and often latent pathogens of equids which can cause fatalities when transmitted to non-equids. Stress and elevated glucocorticoids have been associated with EHV reactivation in domestic horses, but little is known about the correlation between stress and viral reactivation in wild equids. We investigated the effect of an environmental stressor (social group restructuring following a translocation event) on EHV reactivation in captive Grévy's zebras (). A mare was translocated by road transport from Zoo Mulhouse, France, to join a resident group of three ...
Schnabel CL, Wimer CL, Perkins G, Babasyan S, Freer H, Watts C, Rollins A, Osterrieder N, Wagner B.Equine herpesvirus type 1 (EHV-1) induces respiratory infection, abortion, and neurologic disease with significant impact. Virulence factors contributing to infection and immune evasion are of particular interest. A potential virulence factor of the neuropathogenic EHV-1 strain Ab4 is ORF2. This study on 24 Icelandic horses, 2 to 4 years of age, describes the infection with EHV-1 Ab4, or its deletion mutant devoid of ORF2 (Ab4ΔORF2) compared to non-infected controls (each group n = 8). The horses' clinical presentation, virus shedding, viremia, antibody and cellular immune responses were...
Schauer M, Kleinwort KJH, Degroote RL, Wiedemann C, Kremmer E, Hauck SM, Deeg CA.The GTP-binding protein septin 7 is involved in various cellular processes, including cytoskeleton organization, migration and the regulation of cell shape. Septin 7 function in lymphocytes, however, is poorly characterized. Since the intracellular signaling role of septin 7 is dependent on its interaction network, interaction proteomics was applied to attain novel knowledge about septin 7 function in hematopoietic cells. Our previous finding of decreased septin 7 expression in blood-derived lymphocytes in ERU, a spontaneous animal model for autoimmune uveitis in man, extended the role of sept...
Hazlett M, Stalker M, Lake M, Peregrine A.A miniature horse which died following humane seizure from an Ontario farm was emaciated with serous atrophy of fat. Autopsy revealed hepatic atrophy and moderate periportal fibrosis. Eggs and trematodes seen in the liver were identified as Dicrocoelium dendriticum. This appears to be the first reported case of infection of equids in North America with Dicrocoelium dendriticum. Infection parDicrocoelium dendriticumhépatique chez un cheval miniature. Un cheval miniature qui est mort à la suite d’une saisie humanitaire dans une ferme de l’Ontario était émacié et avait une atrophie sére...
Lo Giudice R, Rizzo G, Centofanti A, Favaloro A, Rizzo D, Cervino G, Squeri R, Costa BG, La Fauci V, Lo Giudice G.The use of equine bone blocks is widely reported for bone augmentation techniques. The block must be shaped according to the form of the defect that should be regenerated. The shaping could be performed by hand before or during the surgery, in a sterile ambient, or using a CNC milling machine that could not be sterile. The aim of our study was to evaluate if a steam sterilization could provide a medical grade sterilization of the blocks and to evaluate if bone microstructure and collagen structures change after different steam sterilization protocols provided by mainstream autoclave. Methods: ...
Mawhinney I, Errington J, Stamper N, Torrens N, Engelsma MY, Roest HIJ.Sets of genital swabs are routinely taken from horses to screen for the presence of Taylorella equigenitalis, the cause of contagious equine metritis. Typically, two to four different sites are swabbed at a time and tested by culture or PCR. Objective: This study explored the feasibility of pooling these swabs for a single PCR test per animal instead of testing each swab individually. Methods: In vitro. Methods: PCR signal strengths (Ct values) from 149 historical PCR positive genital swabs, together with historical data on the number of swabs in a set expected to be positive, were used to ass...
Fielding CL, Rhodes DM, Howard EJ, Mayer JR.OBJECTIVE To identify clinical or clinicopathologic variables that can be used to predict a positive PCR assay result for Anaplasma phagocytophilum infection in equids. ANIMALS 162 equids. PROCEDURES Medical records were reviewed to identify equids that underwent testing for evidence of A phagocytophilum infection by PCR assay between June 1, 2007, and December 31, 2015. For each equid that tested positive (case equid), 2 time-matched equids that tested negative for the organism (control equids) were identified. Data collected included age, sex, breed, geographic location (residence at the tim...
Gokbulut C, McKellar QA.Internal parasites of horses comprise an intractable problem conferring disease, production and performance losses. Parasitism can rarely be controlled in grazing horses by management alone and anthelmintic drugs have formed the basis of therapy and prophylaxis for the last sixty years. The pharmacology of the anthelmintic drugs available dictate their spectrum of activity and degree of efficacy, their optimal routes of administration and characteristics which prevent some routes of administration, their safety tolerance and potential toxicities and as a consequence of their persistence in the...
Mendoza E, Bubis J, Pérez-Rojas Y, Montilla AJ, Spencer LM, Bustamante F, Martínez JC.Previously, we have identified a protein in Trypanosoma equiperdum that possesses homology with the regulatory (R) subunits of the mammalian cAMP-dependent protein kinase (PKA). The recombinant T. equiperdum PKA R-like protein was expressed in bacteria and purified to homogeneity. Mice polyclonal antibodies were raised against the recombinant R-like protein to serologically evaluate its humoral immune response. High titers of specific sera antibodies were obtained against the parasite R-like protein by indirect enzyme-linked immunosorbent assay (ELISA), and immunoblots revealed that this prote...
Kennedy CA, Walsh C, Karczmarczyk M, O'Brien S, Akasheh N, Quirke M, Farrell-Ward S, Buckley T, Fogherty U, Kavanagh K, Parker CT, Sweeney T....Extraintestinal pathogenic E. coli (ExPEC) possess the ability to cause extraintestinal infections such as urinary tract infections, neonatal meningitis and sepsis. While information is readily available describing pathogenic E. coli populations in food-producing animals, studies in companion/sports animals such as horses are limited. In addition, many antimicrobial agents used in the treatment of equine infections are also utilised in human medicine, potentially contributing to the spread of antibiotic resistance determinants among pathogenic strains. The aim of this study was to phenotypical...
Bryant HA, Dixon JJ, Weller R, Bolt DM.The diagnostic value of positive contrast radiography in the work-up of suspected synovial infection in horses with limb wounds near synovial structures has yet to be systematically evaluated. Objective: To determine the specificity, sensitivity and positive and negative predictive values of positive contrast radiography for identification of synovial infection in a population of horses with limb wounds. Methods: Retrospective case study comparing the performance of positive contrast radiography to the gold standard of synovial fluid cytology in horses presenting with limb wounds in the vicini...
Durán-Ferrer M, Agüero M, Zientara S, Beck C, Lecollinet S, Sailleau C, Smith S, Potgieter C, Rueda P, Sastre P, Monaco F, Villalba R....The laboratory diagnosis of African horse sickness (AHS) is important for: (a) demonstrating freedom from infection in a population, animals or products for trade (b) assessing the efficiency of eradication policies; (c) laboratory confirmation of clinical diagnosis; (d) estimating the prevalence of AHS infection; and (e) assessing postvaccination immune status of individual animals or populations. Although serological techniques play a secondary role in the confirmation of clinical cases, their use is very important for all the other purposes due to their high throughput, ease of use and good...
Karamalla ST, Gubran AI, Adam IA, Abdalla TM, Sinada RO, Haroun EM, Aradaib IE.African horse sickness virus (AHSV) is an infectious non contagious insect-transmitted double-stranded (ds) RNA orbivirus of the family Reoviridae. AHSV causes an often fatal hemorrhagic infection with high mortality among selected breeds of Arabian horses. This study was conducted to avail some information with regard to the prevalence and associated risk factors of AHSV among ecotype breeds of horses in central Sudan. Methods: Sera were collected from 320 horses, which were selected randomly from four localities and employed in the study. A competitive enzyme-linked immunosorbent assay (cELI...
Riihimäki M, Aspán A, Ljung H, Pringle J.The aim of the study was to use culture, qPCR and seM sequencing to map Streptococcus equi subspec. equi (S.equi) isolates in long term carrier animals. A strangles outbreak affecting 41 Icelandic horses was followed to determine strangles free status using nasal and/or guttural pouch lavages collected serially on eleven separate occasions over 13 months. Ten persistent carriers, of which eight had repeated culture positive samples for S. equi, were selected for the study. Of 115 samples collected, 61 were S. equi positive on qPCR; from which 32 were also culture positive. Amplification of par...
Quercia S, Freccero F, Castagnetti C, Soverini M, Turroni S, Biagi E, Rampelli S, Lanci A, Mariella J, Chinellato E, Brigidi P, Candela M.Even if horses strictly depend on the gut microbiota for energy homeostasis, only a few molecular studies have focused on its characterisation and none on the perinatal gut microbial colonisation process. Objective: To explore the perinatal colonisation process of the foal gut microbial ecosystem and the temporal dynamics of the ecosystem assembly during the first days of life. Methods: Longitudinal study. Methods: Thirteen Standardbred mare-foal pairs were included in the study. For each pair, at delivery we collected the mare amniotic fluid, faeces and colostrum, and the foal meconium. Milk ...
Lu G, Huang J, Li S.Theiler's disease-associated virus (TDAV) could be the aetiological agent of Theiler's disease. Horses experimentally inoculated with equine plasma containing TDAV develop acute and chronic infections with viraemia. Since its first identification in 2013, TDAV has not been detected in equines in the epidemiological studies that have been conducted. Until now, only one genome sequence of TDAV (HorseA1_serum) had been obtained. In this study, we sequenced the genome of four TDAV strains (A/China, F/China, H/USA and I/USA) in commercial equine sera used for cell culture propagation in China using...
Chung C, Mealey RH, McGuire TC.Cytotoxic T lymphocytes (CTL) are important for controlling equine infectious anemia virus (EIAV). Because Gag matrix (MA) and capsid (CA) are the most frequently recognized proteins, the hypothesis that CTL from EIAV-infected horses with diverse MHC class I alleles recognize epitope clusters (EC) in these proteins was tested. Four EC were identified by CTL from 15 horses and 8 of these horses had diverse MHC class I alleles. Two of the eight had CTL to EC1, six to EC2, five to EC3, and four to EC4. Because EC2-4 were recognized by CTL from >50% of horses with diverse alleles, the hypothesi...
Pusterla N, Jones ME, Mohr FC, Higgins JK, Mapes S, Jang SS, Samitz EM, Byrne BA.A case of fatal pulmonary hemorrhage in a 6-year-old American Paint mare with a 2-week history of intermittent coughing, fever, and epistaxis is described. Significant macroscopic abnormalities at postmortem examination were restricted to the respiratory system, and microscopically, severe pulmonary hemorrhage with suppurative bronchopneumonia was found. Actinobacillus equuli subsp. haemolyticus was cultured from a transtracheal wash performed antemortem as well as from the lungs at necropsy. The presence of airway-associated hemorrhage in conjunction with bacterial bronchopneumonia suggested ...
Patel JR, Földi J, Bateman H, Williams J, Didlick S, Stark R.The temperature sensitive and host range mutant clone 147 of equine herpesvirus 1 (EHV-1) was assessed for its ability to protect conventional, susceptible adult horses against respiratory infection by EHV-1 and equine herpesvirus 4 (EHV-4). Intranasal (IN) vaccination with 5.2 log(10) TCID(50) did not cause adverse clinical reactions although a limited virus shedding and viraemia (leukocytes) was observed in 11 of 15 and 10 of 15 vaccinated horses respectively. All 15 vaccinated horses showed a significant seroresponse to both EHV-1 and EHV-4 for virus neutralising (VN) antibody. None of 14 c...
Darnaud SJ, Southwood LL, Aceto HW, Stefanovski D, Tomassone L, Zarucco L.It is our clinical impression that age and incision length are more strongly associated with surgical site infection (SSI) following colic surgery than skin closure or wound protection method. Therefore, the objective of this observational clinical cohort study was to identify the risks for SSI in horses undergoing colic surgery. Data collection included pre-, intra-, and postoperative variables. Variables with P < 0.2 following univariable analysis were used in a logistic regression multivariable model. Variables with P <0.05 were included in the final model. Odds ratios (OR; 95% confid...
Wilmink JM, van Herten J, van Weeren PR, Barneveld A.In accidental wounds, trauma and infection can result in dehiscence of primarily closed wounds and in sequestrum formation when cortical bone is exposed. In experimental studies, it has been shown that second intention healing is faster and occurs with less complications in ponies than in horses. Also, a greater initial inflammatory response was seen in ponies. Based on these experimental data, it was hypothesised that accidental wounds in ponies would heal with a lower incidence of wound dehiscence and/or sequestrum formation compared to horses. A retrospective study of 89 ponies and 422 hors...
Nomura M, Kuroda T, Tamura N, Muranaka M, Niwa H.Although Clostridioides difficile-associated diseases (CDAD) is considered to be associated with colitis in horses, few studies have been performed with a focus on the characteristics of CDAD in thoroughbred racehorses. Between 2010 and 2018, a test for C. difficile was performed using faecal samples from 137 thoroughbred racehorses with colitis presenting with diarrhoea and fever. The mortality rate, clinical findings, predisposing factors and the selected treatments were investigated in a retrospective manner. Twenty-four cases were diagnosed as CDAD and 113 as non-CDAD. The mortality rate w...
Whalley JM, Ruitenberg KM, Sullivan K, Seshadri L, Hansen K, Birch D, Gilkerson JR, Wellington JE.Equine herpesviruses 1 and 4 (EHV-1 and EHV-4) cause equine respiratory disease worldwide. However, only EHV-1 is a cause of abortion and neurological disease, despite the two viruses having all 76 genes in common. In addition EHV-1 has a broader host range in cell culture than EHV-4, as exemplified by the rabbit kidney (RK) cell line that is permissive for EHV-1, but not for EHV-4. Here we describe that when EHV-4 produced in equine cells was inoculated onto RK cells expressing glycoprotein D of EHV-1 (RKgD1), infection developed as clusters of rounded cells, and this infectivity could be pas...
Bleumink-Pluym NM, Werdler ME, Houwers DJ, Parlevliet JM, Colenbrander B, van der Zeijst BA.A PCR for the detection of Taylorella equigenitalis, the causative agent of contagious equine metritis, was developed and evaluated. A genus-specific primer-probe set was derived from the 16S ribosomal DNA sequences. The PCR was specific and amplified a 585-bp product from all 64 available T. equigenitalis isolates. This PCR product hybridized with a specific probe in a dot spot assay. A variety of microorganisms from the genital tracts of horses or with a close phylogenetic relationship to T. equigenitalis did not yield a visible PCR product and were all negative in the dot spot hybridization...
Brown K, Moreton J, Malla S, Aboobaker AA, Emes RD, Tarlinton RE.The recently released draft horse genome is incompletely characterised in terms of its repetitive element profile. This paper presents characterisation of the endogenous retrovirus (ERVs) of the horse genome based on a data-mining strategy using murine leukaemia virus proteins as queries. 978 ERV gene sequences were identified. Sequences were identified from the gamma, epsilon and betaretrovirus genera. At least one full length gammaretroviral locus was identified, though the gammaretroviral sequences are very degenerate. Using these data the RNA expression of these ERVs were derived from RNA ...
Shin J, Ahn KS, Suh GH, Kim HJ, Jeong HS, Kim BS, Choi E, Shin SS.Ocular setariases of cattle were reported but those of equine hosts have never been reported in the Republic of Korea (Korea). We found motile worms in the aqueous humor of 15 horses (Equus spp.) from 12 localities in southern parts of Korea between January 2004 and November 2017. After the affected animals were properly restrained under sedation and local anesthesia, 10 ml disposable syringe with a 16-gauge needle was inserted into the anterior chamber of the affected eye to successfully remove the parasites. The male worm that was found in 7 of the cases showed a pair of lateral appendages n...
Go YY, Bailey E, Timoney PJ, Shuck KM, Balasuriya UB.We investigated the correlation between in vitro susceptibility of CD3(+) T lymphocytes to equine arteritis virus (EAV) infection and establishment of persistent infection among 14 stallions following natural infections. The data showed that carrier stallions with a CD3(+) T lymphocyte susceptibility phenotype to in vitro EAV infection may be at higher risk of becoming carriers than those that lack this phenotype (P = 0.0002).
Black WD, Wilcox RS, Stevenson RA, Hartley CA, Ficorilli NP, Gilkerson JR, Studdert MJ.The objective of this study was to determine the incidence of serum neutralising (SN) antibody to ERAV, ERBV1 and ERBV2 in a population of horses from birth to 22 years of age. The prevalences of ERAV, ERBV1 and ERBV2 SN antibodies in 381 sera obtained from 291 horses were 37%, 83% and 66%, respectively. ERAV, ERBV1 and ERBV2 maternal antibody was present in foals 12 h postsuckling but by 10-12 months, ERAV SN antibody was not detected in any of the horses, while ERBV1 and ERBV2 SN antibodies were common (83% and 100%, respectively). Sera were obtained from 44 Thoroughbred horses when they wer...
Lian WC, Liau MY, Mao CL.Nervous disorders were found in two horses and verified as aseptic encephalitis by necropsy in the summer of 2000. To investigate agents that affected the horses, diagnostic procedures involving virus isolation, neutralization test and reverse transcription-polymerase chain reaction (RT-PCR) were performed. We intracranially inoculated litters of suckling mice with tissues suspected of containing aseptic encephalitis, including cerebrum, cerebellum, brain stem, thalamus, and cerebrospinal fluids; the mice were then observed for 14 days. Neutralizing antibodies against Japanese encephalitis (JE...
Lang J, Simanjuntak GH, Soerjosembodo S, Koesharyono C.WHO's reference protocol for post-exposure rabies vaccination advises five intramuscular injections on days 0, 3, 7, 14, and 30; in addition, rabies immunoglobulins (RIG) must be given to serious cases of exposure (grade III severity). Some studies indicate that these immunoglobulins suppress the immunogenicity of rabies vaccine when administered according to an alternative protocol of four injections (2-1-1) on days 0, 7, and 21, which was therefore not recommended for grade III exposures. To test this effect, we conducted a multicentre study in Indonesia using three groups of subjects. One g...
Høyer-Nielsen AK, Gaini S, Kjerulf A, Kollslíð R, Steig TÁ, Stegger M, Jóanesarson J. subspecies () is mostly known as an opportunistic pathogen found in horses and as a rare human zoonosis. An 82-year-old male, who had daily contact with horses, was admitted in a septic condition. The patient presented with dyspnea, hemoptysis, impaired general condition, and severe pain in a swollen left shoulder. Synovial fluid from the affected joint and blood cultures showed growth of subsp. . Transesophageal echocardiography showed a vegetation on the aortic valve consistent with endocarditis. Arthroscopic revision revealed synovitis and erosion of the rotator cuff. Technetium-99m scin...
Breathnach CC, Yeargan MR, Sheoran AS, Allen GP.Equine herpesvirus-1 (EHV-1) remains a frequent cause of upper respiratory tract infection and abortion in horses worldwide. However, little is known about the local antibody response elicited in the upper airways of horses following exposure to EHV-1. This study analysed the mucosal humoral immune response of weanling foals following experimental infection with virulent EHV-1, or vaccination with either of 2 commercial vaccines. Twenty weanlings were assigned to 5 groups and were inoculated with, or vaccinated against, EHV-1 following different regimens. Finally, all weanlings were simultaneo...
Lyons ET, Tolliver SC.Critical tests were performed in 2011 in four weanling horses (L-1, L-2, L-29, and L-30) treated with ivermectin paste at 200 μg/kg. They were born in 2011 and raised together on a farm (MC) in Central Kentucky. The horses had not been treated previously with an antiparasitic drug. However, ivermectin had been administered repeatedly to the horse herd for several years and strongyle eggs per gram of feces (EPGs) returned sooner posttreatment than after initial usage. Critical tests in a recent previous study in this horse herd indicated that the reason for the early return of strongyle EPGs a...
Lawton KOY, Arthur RM, Moeller BC, Barnum S, Pusterla N.More and more studies are reporting on the natural transmission of SARS-CoV-2 between humans with COVID-19 and their companion animals (dogs and cats). While horses are apparently susceptible to SARS-CoV-2 infection based on the homology between the human and the equine ACE-2 receptor, no clinical or subclinical infection has yet been reported in the equine species. To investigate the possible clinical role of SARS-CoV-2 in equids, nasal secretions from 667 horses with acute onset of fever and respiratory signs were tested for the presence of SARS-CoV-2 by qPCR. The samples were collected from...
Hildreth SW, Beaty BJ, Maxfield HK, Gilfillan RF, Rosenau BJ.Enzyme immunoassays (EIAs) for eastern equine encephalomyelitis (EEE) and Highlands J (HJ) virus antigens were compared in a retrospective study with standard virus isolation procedures (VIP) for detection of alpha virus-infected mosquito pools. The original VIP was a plaque assay in chick embryo cell culture, and was performed in the years from 1979 to 1981. Using the original VIP as the reference standard, the sensitivity rate of the EIA was 0.7674 and the false negative rate was 0.2326. However, when the storage age and the initial virus titer of the sample were considered, the sensitivity ...
Parreira DR, Jansen AM, Abreu UG, Macedo GC, Silva AR, Mazur C, Andrade GB, Herrera HM.Equine infectious anemia virus (EIAV) and Trypanossoma evansi are endemic in Brazilian Pantanal Biome, an important area for livestock production. In this sense, we evaluated the epidemiological single and co-infection effects of T. evansi and EIAV in naturally infected horses in the southern Pantanal wetland by serological tests and hematological assays. Both higher seroprevalence and heath poor condition of the sampled animals were associated with differences in horse management between farms. We found that the negative animals for both infectious agents (NN) represented the major group in F...
Patel JR, Bateman H, Williams J, Didlick S.A German abortion isolate of EHV-1 (strain M8) was grown in equine dermal (ED) cells at a low multiplicity of infection in presence of 5-bromo-2-deoxy uridine. The resulting stock was dialysed, titrated and cloned by terminal dilution in ED cells grown in 96-well microtitration plates. Of 192 clones each originating from a single focus, clone 147 (C147) was found to be restricted for growth at and above temperatures of 38.5 degrees C. It was also restricted for growth at 37 degrees C in rabbit kidney (RK-13) cells which are widely used for the isolation and titration of EHV-1; hence clone 147 ...
Katz JB, Evans LE, Hutto DL, Schroeder-Tucker LC, Carew AM, Donahue JM, Hirsh DC.To characterize clinical, serologic, bacteriologic, cytologic, and pathologic endometrial responses of mares to 2 donkey-origin atypical bacterial isolates resembling Taylorella equigenitalis. Methods: Prospective in vivo study. Methods: 10 healthy mares. Methods: Mares in estrus (2/group) were inoculated by intrauterine infusion with 2 isolates of classic T equigenitalis or 2 isolates of atypical Taylorella sp or were sham-inoculated. Bacteriologic, serologic, clinical, uterine, cytologic, and pathologic endometrial responses were assessed 4, 11, 21, 35, and 63 days after inoculation and on d...
Di Pietro R, Arroyo LG, Leclere M, Costa MC.All current studies have used Illumina short-read sequencing to characterize the equine intestinal microbiota. Long-read sequencing can classify bacteria at the species level. The objectives of this study were to characterize the gut microbiota of horses at the species level before and after trimethoprim sulfadiazine (TMS) administration and to compare results with Illumina sequencing. Nine horses received TMS (30 mg/kg) orally for 5 days twice a day to induce dysbiosis. Illumina sequencing of the V4 region or full-length PacBio sequencing of the 16S rRNA gene was performed in fecal samples co...
Dunowska M, Howe L, Hanlon D, Stevenson M.The significance of infection with Equid herpesvirus 2 (EHV-2) remains unresolved, mainly due to its widespread distribution, and frequent isolation of the virus not only from diseased animals, but also from clinically normal horses. It has been suggested that EHV-2 exerts its effects on the host indirectly, through predisposition to secondary infections. The aim of this study was to determine kinetics of EHV-2 infection among foals and to investigate the role that EHV-2 may play in development of Rhodococcus equi pneumonia on one farm. Serial blood samples were collected from 43 foals over a ...
Archer DC, Pinchbeck GK, French NP, Proudman CJ.Epiploic foramen entrapment (EFE) is one of the most common causes of small intestinal strangulation in the horse. Identification of risk factors would generate hypotheses about causation and may suggest preventive strategies. Objective: Horses exhibiting certain behavioural patterns and those exposed to particular management practices are at increased risk of EFE. Methods: A matched case-control study was conducted on EFE cases admitted to hospitals in the UK, Ireland and USA. Data on 109 cases and 310 control horses were obtained by telephone questionnaire and conditional logistic regression...
Zevenhoven-Dobbe JC, Greve S, van Tol H, Spaan WJM, Snijder EJ.Equine arteritis virus (EAV) contains seven structural proteins that are all required to produce infectious progeny. Alphavirus-based expression vectors have been generated for each of these proteins to explore the possibilities for their constitutive expression in cell lines. This approach was successful for minor glycoproteins GP(2b), GP(3) and GP(4) and for the E protein. Subsequently, it was demonstrated that cell lines expressing these proteins could rescue EAV mutants that were disabled in the expression of the corresponding gene, resulting in the production of virus particles carrying t...
Kim SK, Kim S, Dai G, Zhang Y, Ahn BC, O'Callaghan DJ.The equine herpesvirus 1 (EHV-1) negative regulatory IR2 protein (IR2P), an early 1,165-amino acid (aa) truncated form of the 1487-aa immediate-early protein (IEP), lacks the trans-activation domain essential for IEP activation functions but retains domains for binding DNA, TFIIB, and TBP and the nuclear localization signal. IR2P mutants of the N-terminal region which lack either DNA-binding activity or TFIIB-binding activity were unable to down-regulate EHV-1 promoters. In EHV-1-infected cells expressing full-length IR2P, transcription and protein expression of viral regulatory IE, early EICP...
Upjohn MM, Shipton K, Lerotholi T, Attwood G, Verheyen KL.This study aimed to (1) estimate infection prevalence of strongyle, Oxyuris equi and Parascaris equorum species and the intensity of infection with strongyles in working horses in lowland Lesotho and (2) investigate associations between infection and horse age, sex and owner-reported use of anthelmintics. In a cross-sectional survey, fresh faecal samples were obtained from 305 randomly selected horses and worm egg counts performed using a validated field laboratory kit. Details of anthelmintic use were collected using a standardised face-to-face owner questionnaire. Infection prevalence estima...
Roy MF.Sepsis develops in horses when the host response to the invading pathogens is not properly balanced according to the severity of the insult. Several clinical conditions frequently encountered in equine practice may be associated with the development of sepsis and have the potential to progress to more severe forms, such as severe sepsis, MODS, and septic shock. Consequently, it is important for equine practitioners to be aware of the manifestations,pathophysiology, and treatment of sepsis. Although enormous progress has been made in recent years in our understanding of the pathophysiology of s...
Duncan JL, Bairden K, Abbott EM.The efficacy of five daily treatments with 7.5 mg fenbendazole/kg bodyweight against mucosal cyathostome larvae was evaluated in 20 12- and 24-month-old ponies with naturally acquired cyathostome infections. After three weeks communal grazing on infected pasture and six weeks indoors, one group of 10 ponies were treated. Six weeks later, both groups of ponies were humanely destroyed and their burdens of large intestinal cyathostome worms, including luminal parasites and mucosal larvae, were assessed. In the control animals approximately 7 per cent of the total worm burden was present in the gu...
