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.
Hodgson C, Pinchbeck G.Despite the regularity with which castration is performed, the types of complications and current best practice are unknown. Objective: The objective of this study was to perform a prospective audit of routine equine castrations performed in general practice to determine complication rates and factors associated with them. Methods: Multicentre, prospective audit of castrations. Methods: Data on castrations were collected on the day of surgery from 18 veterinary practices; 30-days post-operatively follow-up was obtained and complications recorded. Frequency of complications was reported, and mu...
Jones ARE, Ragle CA.CASE DESCRIPTION 2 fillies, aged 3 months and 1 month, were examined because of urinary incontinence and urine scalding. CLINICAL FINDINGS In horse 1, ultrasonography did not reveal any structural abnormalities of the kidneys; however, unilateral ureteral ectopia was diagnosed cystoscopically. In horse 2, CT revealed bilateral nephropathy, bilateral distended ureters (up to 3.6 cm in diameter), and bilateral ureteral ectopia. Cystoscopy revealed intramural ureteral ectopia with abnormally caudally positioned ureteral ostia in both horses. TREATMENT AND OUTCOME Ureteral ostioplasty was performe...
Charvet CL, Guégnard F, Courtot E, Cortet J, Neveu C.The control of parasitic nematodes impacting animal health relies on the use of broad spectrum anthelmintics. However, intensive use of these drugs has led to the selection of resistant parasites in livestock industry. In that respect, there is currently an urgent need for novel compounds able to control resistant parasites. Nicotine has also historically been used as a de-wormer but was removed from the market when modern anthelmintics became available. The pharmacological target of nicotine has been identified in nematodes as acetylcholine-gated ion channels. Nicotinic-sensitive acetylcholin...
Frees KE.The goal of wound cleansing and care is the control or removal of tissue infection to allow healing in the most functional, cosmetic, fastest, and least expensive manner possible. This is accomplished through the removal of debris and necrotic tissue while reducing the bacterial load via careful use of mechanical techniques and cleaning agents, accepting that some level of tissue trauma will result. Keep in mind that the benefit of a clean wound must be weighed against the trauma inflicted in the process of cleansing. Veterinary health care professionals should take steps to reduce hospital-ac...
Leise BS.Topical therapies are used in equine wound healing to clean and decontaminate the wound environment after acute injury and to promote healing and decrease the risk of infection once the wound has initially been treated. Evolving antibiotic resistance has prompted judicious use of systemic antimicrobials, particularly in the treatment of local infections, such as wounds. The use of topical antiseptics to disinfect acute wounds and topical antimicrobials to manage chronic wounds is necessary to achieve successful healing. In addition, many topical medications can alter the wound environment to p...
Ludwig EK, van Harreveld PD.Equine septic synovitis commonly occurs secondary to traumatic wounds. The distal limbs of horses have minimal soft tissue protection, thus wounds in these areas are more likely to involve adjacent synovial structures. Synovial sepsis can be debilitating due to difficulties clearing established infections and the degenerative changes that result from ongoing inflammation. Prompt diagnosis allows for immediate treatment, improving the prognosis. Goals for successful treatment of infected synovial structures due to wounds include early and accurate recognition of the condition, rapid resolution ...
Maher M, Kuebelbeck L.Nonhealing wounds present a common challenge to the equine practitioner. An underlying source of inflammation and infection is almost always present and needs to be resolved for healing to proceed. Wound débridement is the mainstay for this resolution. In addition, wound closure, wound dressings, and skin grafts can be used to achieve successful wound healing.
Schöniger S, Gräfe H, Wipplinger M, Schoon HA.In mares, placental diseases are a common cause of pregnancy failure and they can have an economic impact on the horse breeding industry. To our knowledge no published data on TLR expression in the equine placenta exist. This study examined the expression of TLR 2, 4 and 6 as transcript and protein in the placenta (chorioallantois) of 14 foals born alive. By PCR, all examined placental samples contained TLR 2, 4 and 6 transcripts. Using immunohistochemistry, trophoblasts and allantoic epithelium were immunopositive for TLR 2, 4 and 6 in all placental samples. The majority of placental samples ...
Al-Kass Z, Spergser J, Aurich C, Kuhl J, Schmidt K, Morrell JM.Bacteria contaminate semen during collection and handling. The objective of this study was to identify the bacteria in pony stallion semen, the effects of antibiotics included in commercial semen extenders (lincomycin and spectinomycin) and the effect of modified single layer centrifugation (MSLC), on bacterial load. Ejaculates from six pony stallions, 3 ejaculates per animal, were extended in EquiPlus extender either with or without antibiotics. Aliquots were processed by MSLC to form four treatment groups: control and MSLC with antibiotics (CA and SA, respectively) and control and MSLC witho...
Jo A, Lee HE, Kim HS.Horses (Equus caballus) have been domesticated and bred to enhance speed, strength, and agility. Members of the Equus caballus Endogenous Retrovirus (EqERV) family affect several of these abilities in horses. EqERV elements have been integrated in the horse genome during evolution and generate repeat elements such as long terminal repeats (LTRs). LTR sequences are involved in retrovirus replication and play an essential function in post-transcriptional control mechanisms, such as by providing binding sites for microRNAs (miRNAs) or generating miRNA precursors. In this study, we identified a no...
Wimer CL, Schnabel CL, Perkins G, Babasyan S, Freer H, Stout AE, Rollins A, Osterrieder N, Goodman LB, Glaser A, Wagner B.The equine herpesvirus type 1 (EHV-1) ORF1 and ORF71 genes have immune modulatory effects in vitro. Experimental infection of horses using virus mutants with multiple deletions including ORF1 and ORF71 showed promise as vaccine candidates against EHV-1. Here, the combined effects of ORF1 and ORF71 deletions from the neuropathogenic EHV-1 strain Ab4 on clinical disease and host immune response were further explored. Three groups of EHV-1 naïve horses were experimentally infected with the ORF1/71 gene deletion mutant (Ab4ΔORF1/71), the parent Ab4 strain, or remained uninfected. In comparison t...
Attia MM, Khalifa MM, Mahdy OA. larvae are of veterinary and medical importance caused specific equine intestinal myiasis. (Botfly larvae) had a wide geographical distribution. The present study explores the prevalence rate of 3 stage larvae in Egypt from January- December 2017; besides, in vitro trials to control of this larvae and evaluation of this trial using Scanning Electron Microscope (SEM) and histopathology of treated larvae. In the present study, the 3 larval stage of was found in clusters in the epithelium of the investigated stomach and infested with prevalence rate 97.2%. The highest collected numbers of lar...
Mehdizadeh Gohari I, Boerlin P, Prescott JF.NetF-producing type A Clostridium perfringens, a pathotype of C. perfringens, causes necrotizing enteritis in neonatal foals and necrotizing and hemorrhagic enteritis in dogs. Recent core genome multilocus sequence typing study revealed that netF+ C. perfringens strains belong to two distinct clonal populations (clonal complexes I and II). There are no reports on susceptibility to antimicrobial drugs of isolates from this pathotype. The susceptibility to 13 different antimicrobial drugs of 49 netF+ strains recovered from foals or dogs with necrotizing enteritis in Canada, the United States, an...
Montes Cortés MG, Fernández-García JL, Habela Martínez-Estéllez MÁ.Two haemoparasites, Theileria equi and Babesia caballi, cause equine piroplasmosis (EP), one of the most prevalent tick-borne diseases in horses. The main aim of the present study was to develop and evaluate a multinested PCR (mn-PCR) for simultaneous detection of the equine piroplasmids T. equi and B. caballi, by amplification of five genetic markers (18S rRNA, β-tubulin, cytB, EMA-1 and RAP-1). This novel assay detected a high prevalence of equine piroplasmids in 235 horse blood samples collected in Castilla-León and Extremadura, Spain. The overall prevalence of infection with equine pirop...
Cook RF, Barrandeguy M, Lee PA, Tsai CF, Shen YH, Tsai YL, Chang HG, Wang HT, Balasuriya UBR.Control of equine infectious anaemia (EIA) currently depends on serological diagnosis of infected equids. However, recently infected equids may not produce detectable anti-EIAV antibodies up to 157 days post infection and so present a high transmission risk. Therefore, direct nucleic acid detection methods are urgently needed to improve EIAV surveillance and management programs in counties where the disease is endemic. Objective: To evaluate a field-deployable, reverse transcription-insulated isothermal PCR (RT-iiPCR) assay targeting the conserved 5' untranslated region (5' UTR)/exon 1 of the ...
Scharner D, Gittel C, Winter K, Blaue D, Schedlbauer C, Vervuert I, Brehm W.Development of incisional complications following ventral median celiotomy might depend on suture pattern for skin closure. Methods: In this prospective study, 21 healthy male horses underwent celiotomy. Skin closure was either performed via a continuous percutaneous pattern (CO group; 5 warmbloods/5 ponies) or an intradermal pattern (ID group; 5 warmbloods/6 ponies). Follow-up examination of the incisional site included daily monitoring for edema, dehiscence, and drainage. Transcutaneous ultrasound was performed at Days 3, 6, and 10 as well as on Week 8 and 12 to evaluate size of edema and pr...
Hébert L, Guitton E, Madeline A, Géraud T, Zientara S, Laugier C, Hans A, Büscher P, Cauchard J, Petry S.The aim of this study was to evaluate the ability of melarsomine hydrochloride (Cymelarsan) to cure horses suffering from a nervous form of dourine, a sexually-transmitted disease caused by Trypanosoma equiperdum. The recently described experimental model for assessing drug efficacy against horse trypanosomosis allowed us to obtain eight horses (Welsh pony mares) infected by T. equiperdum with parasites in their cerebrospinal fluid. The Cymelarsan treatment evaluated consisted of the daily administration of 0.5 mg/kg of Cymelarsan over 7 days. Two control horses remained untreated, three hor...
Hunyadi L, Papich MG, Pusterla N.The purpose of this study was to determine if a low dose of diclazuril (0.5mg/kg of 1.56% diclazuril pellets) given to six healthy adult horses every 3-4 days for a total of five administrations would achieve steady-state plasma concentrations known to be inhibitory to Sarcocystis neurona and Neospora caninum. Blood was collected via venipuncture immediately before (trough concentrations) and 10h after (peak concentrations) each diclazuril administration and analysed by high-pressure liquid chromatography. The mean population-derived peak concentration was 0.284μg/mL and the mean terminal hal...
Raza A, Qamar AG, Hayat K, Ashraf S, Williams AR.Control of equine nematodes has relied on benzimidazoles (BZs), tetrahydropyrimidines and macrocyclic lactones. The intensive use of anthelmintics has led to the development of anthelmintic resistance (AR) in equine cyathostomins and Parascaris equorum. Field studies indicate that BZ and pyrantel resistance is widespread in cyathostomins and there are also increasing reports of resistance to macrocyclic lactones in cyathostomins and P. equorum. The unavailability of reliable laboratory-based techniques for detecting resistance further augments the problem of nematode control in horses. The onl...
Theelen MJP, Beukers M, Grinwis GCM, Sloet van Oldruitenborgh-Oosterbaan MM.Iron toxicosis is rarely reported in horses and chronic excessive oral iron intake has not been reported to cause clinical symptoms in equids. Objective: This case series describes 21 genetically unrelated horses and one donkey with chronic iron overload causing haemochromatosis and hepatopathy. Methods: Case series. Methods: All equids showing clinical signs compatible with chronic liver disease presented to Utrecht University and diagnosed with iron overload and haemochromatosis based on histopathological evaluation of liver tissue and/or blood transferrin saturation levels of >80% and proof...
Torsteinsdottir S, Scheidegger S, Baselgia S, Jonsdottir S, Svansson V, Björnsdottir S, Marti E.Insect bite hypersensitivity (IBH) is an IgE-mediated dermatitis caused by bites of Culicoides spp., which occurs frequently in horses imported from Iceland to continental Europe. IBH does not occur in Iceland because Culicoides species that bite horses are not present. However, Simulium vittatum (S. vittatum) are found in Iceland. In Europe, blood basophils from IBH-affected horses release significantly more sulfidoleukotrienes (sLT) than those from healthy controls after in vitro stimulation with Culicoides nubeculosus (C. nubeculosus) and S. vittatum. Aims of the study were: (I) using the s...
Peter V, Marr C, Foote A, Auer H, Head M.This case report describes a 13-year-old cob-cross gelding presented for evaluation of recent onset hindlimb ataxia. The gelding had undergone general anaesthesia and tenoscopy of the right hindlimb digital flexor tendon sheath at a nearby clinic three months earlier and had appeared normal at routine post-operative assessments until the sudden onset of neurological deficits. Spinal trauma was suspected initially but radiography and scintigraphy were unremarkable. Due to the severity and progressive nature of the clinical signs the -gelding was subjected to euthanasia. Post mortem examinations...
Fouché N, Gerber V, Thomann A, Perreten V.We report blood culture results of 43 foals admitted to an equine hospital for medical or surgical disorders and determine minimal inhibitory concentrations (MIC) of different antibiotics. Eleven foals had a positive blood culture result despite prior administration of antibiotics in 10 of these animals. MIC values above EUCAST and/or CLSI breakpoints were identified in coagulase-negative staphylococci, methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecium. Gram-negative isolates were less frequently identified and did not appear to exhibit increased MIC values. This stud...
Younkin JT, Santschi EM, Kukanich B, Lubbers BV, Warner M.Penicillin is administered intravenously (IV) or intramuscularly (IM) to horses for the prevention and treatment of infections, and both routes have disadvantages. To minimize these shortcomings, a 24-hr hybrid administration protocol (HPP) was developed. Our objective was to determine penicillin plasma concentrations in horses administered via HPP. Venous blood was collected from seven healthy horses administered IV potassium penicillin G at 0 and 6 hr and IM procaine penicillin G at 12 hr. Blood was collected at 2-hr intervals from 0 to 20 hr and at 24 hr. Plasma penicillin concentration...
Elad D.This review focuses on aspects of antimycotic therapy specific to veterinary medicine. In the first part, drug availability, limited mostly by economic consideration but also by clinical applicability and specific adverse effects, is described for polyenes, 5 fluorocytosine, azoles, echinocandins and terbinafine. In the second part, current knowledge and experience in the treatment of selected fungal infections are overviewed. These mycoses include disseminated mold infections in small animals (dogs and cats) and avian species, upper respiratory tract infections of small animals (sino-nasal an...
Parashar R, Singla LD, Gupta M, Sharma SK.The haemato-biochemical indices and oxidative stress markers in horses naturally infected with Trypanosoma evansi were evaluated by analyzing the level of these parameters between T. evansi infected (microscopically positive patent group and PCR positive latent group) and infection free horses. To compare the hemato-biochemical indices and oxidative stress indicators, horses were divided into three categories based on diagnostic test employed and positive results obtained. These included Romanowsky stained slide positive group (Group I; n = 6), PCR positive group (group II; n = 28) and negativ...
Ogden NKE, Jukic CC, Zedler ST.To describe a surgical technique for rostral mandibulectomy and reconstruction of the mandibular symphysis. Methods: Case report. Methods: One 5-month-old warmblood cross filly. Methods: A preoperative diagnosis of a juvenile ossifying fibroma was made on the basis of clinical appearance and was later confirmed via histology. The tumor was large, rapidly growing and extending to the caudal aspect of the mandibular symphysis. Computed tomography was performed for surgical planning. The tumor was excised by performing a mandibulectomy caudal to the symphysis. The mandibular symphysis was reconst...
Racine J, Vidondo B, Ramseyer A, Koch C.To describe a closed castration technique in standing equids, report associated complications, and identify potential risk factors. Methods: Prospective cohort study of 300 standing equids that were castrated with the Henderson Equine Castrating Instrument. Methods: Thirteen participating veterinarians recorded intraoperative difficulties and postoperative complications. Descriptive statistics, univariate analyses with Fisher's exact tests, and logistic regressions were used to evaluate intraoperative difficulties and postoperative complications and to assess risk factors for postoperative com...
Schlottau K, Fereidouni S, Beer M, Hoffmann B.Hepatitis C virus (HCV) is a positive-sense RNA virus belonging to the genus Hepacivirus, family Flaviviridae. Its genome has a length of 9.6 kb and encodes a single polyprotein flanked by two untranslated regions. HCV can cause liver cirrhosis and hepatocellular carcinoma, and approximately 2% of the world's population is chronically infected. The investigation of pathogenesis is complicated due to the lack of an animal model. The origin of this virus remains unclear, but in the last few years, relatives of HCV were initially identified in dogs and later in horses, rodents, bats and Old World...
Walther B, Klein KS, Barton AK, Semmler T, Huber C, Merle R, Tedin K, Mitrach F, Lübke-Becker A, Gehlen H.Continuing introduction of multi-drug resistant, zoonotic pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) in horse clinics challenges the biosafety of employees and animal patients. This study was aimed to determine the occurrence of mobile genetic elements facilitating survival in the early stages of invasive infection in different host species, including humans and horses, in MRSA carried by equine patients admitted to a large horse clinic. A total of 341 equine patients were investigated for carriage of MRSA by hygiene screening directly at hospital admission. MRSA were...
Reubel GH, Barlough JE, Madigan JE.We report on the production and characterization of Ehrlichia risticii, the agent of Potomac horse fever (PHF), from snails (Pleuroceridae: Juga spp.) maintained in aquarium culture and compare it genetically to equine strains. Snails were collected from stream waters on a pasture in Siskiyou County, Calif., where PHF is enzootic and were maintained for several weeks in freshwater aquaria in the laboratory. Upon exposure to temperatures above 22 degrees C the snails released trematode cercariae tentatively identified as virgulate cercariae. Fragments of three different genes (genes for 16S rRN...
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...
