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.
Jeske JM, Spier SJ, Whitcomb MB, Pusterla N, Gardner IA.To estimate likelihood ratios (LRs) of correctly identifying internal Corynebacterium pseudotuberculosis infection in horses by measurement of antibody titers via serum synergistic hemolysis inhibition (SHI) testing. Methods: Retrospective case-control study. Methods: 170 horses (171 records; 92 cases of C pseudotuberculosis infection and 79 controls). Methods: Medical records were reviewed, and horses were grouped on the basis of evidence of internal or external C pseudotuberculosis infection. The LRs and 95% confidence intervals for identification of internal C pseudotuberculosis infection b...
Arnold CE, Chaffin MK.To determine clinical signs, diagnostic methods, treatment, and outcome for a series of adult horses with abdominal abscesses. Methods: Retrospective case series. Methods: 61 adult horses. Methods: Medical records of adult horses with abdominal abscesses treated at Texas A&M Veterinary Medical Teaching Hospital (1993 to 2008) were reviewed. Information was recorded regarding signalment, history, clinical signs, diagnosis, treatment, and short- and long-term outcomes. Risk factors for survival were determined. Results: 61 horses met the criteria for inclusion. Clinical signs included colic ...
Rubio-Martínez LM, Elmas CR, Black B, Monteith G.To describe the clinical use of regional limb perfusion with antimicrobials (A-RLP), complications, and outcome in a large series of patients. Methods: Retrospective case series. Methods: 174 horses. Methods: Medical records of horses treated with A-RLP between 1999 and 2009 were reviewed. Signalment, primary complaint, horse use, etiology, duration of clinical signs, previous treatment, structures involved, concurrent conditions, A-RLP characteristics, additional treatments, complications, and outcome were recorded. At long-term follow-up, 2 outcomes were investigated: survival rate and retur...
Yeşilbağ K, Herzog S, Kennerman E, Tuncer P, Schmid S, Kaya G, Thiel HJ.Distribution of Borna disease virus (BDV) infection outside endemic areas has been studied in several countries. We examined serum samples for anti-BDV antibodies in purebred racing horses and other domestic animals in Turkey. In total serum samples of 437 animals including 282 horses, 50 sheep, 25 goats, 50 cattle, and 30 cats were tested by indirect immunofluorescence assay (IFA). Anti-BDV antibodies were detected in 4.9% of horses, 12% of sheep, 4% of goats, 14% of cattle and 6.6% of cats. No statistical difference was observed between seroprevalence in Arabic and English purebred horses fr...
Osińska E, Golke A, Słońska A, Cymerys J, Bańbura MW, Dzieciatkowski T.Equid herpesvirus type 2 (EHV-2) together with equid herpesvirus type 5 are members of Gammaherpesvirinae subfamily, genus Rhadinovirus. EHV-2 is one of major agents causing diseases of horses common worldwide. A possible role of EHV-2 in reactivating latent equid herpesvirus type-1 has been suggested, because reactivation of latent EHV-1 was always accompanied by EHV-2 replication. Variety techniques, including cell culture, PCR and its modifications, have been used to diagnose EHV-2 infections. The aim of this study was to develop, optimize and determine specificity of real-time PCR (qPCR) f...
Tsujita H, Plummer CE.To describe and evaluate intrastromal and subconjunctival injection of voriconazole for the therapy of deep corneal stromal abscess (DSA) in horses. Methods: A retrospective clinical study describing the indications for intrastromal and subconjunctival voriconazole injection and the outcomes of this procedure in two eyes of two horses. Methods: The two horses in this study failed to respond to medical therapy. Treatment with intracorneal and subconjunctival administration of 1% voriconazole was performed in this study. Results: Treatment with intracorneal and subconjunctival administration of ...
Zeiss C, Neaderland M, Yang FC, Terwilliger G, Compton S.To assess the diagnostic utility of fungal polymerase chain reaction (PCR) in forty-three horses with naturally acquired corneal ulcers presenting to a private practice. Methods: Routine evaluation of cytologic, histologic, and microbiologic samples was performed. Two PCR approaches were compared - generic and specific fungal nested PCR followed by sequencing and quantitative PCR (qPCR). PCRs were applied to pure control fungal cultures, corneal tissue from ulcerated eyes and in a subset of 9 horses, to swabs from contralateral normal eyes. Results: The expected fungus was identified by nested...
Bischofberger AS, Dart CM, Perkins NR, Kelly A, Jeffcott L, Dart AJ.To compare the effects of manuka honey and manuka honey gel on second intention healing of noncontaminated distal limb wounds and those contaminated with feces. Methods: Experimental study. Methods: Standardbred horses (n = 10). Methods: Five full-thickness wounds (2 × 2 cm) were created on both metacarpi. Wounds on 1 forelimb were covered with horse feces for 24 hours. Wounds on the contralateral limb were left uncontaminated. Wounds were assigned to the following 5 different treatments: manuka honey, manuka honey gel or gel applied for 12 days, manuka honey gel applied throughout healing an...
Kinnunen PM, Palva A, Vaheri A, Vapalahti O.Borna disease virus (BDV) has gained lot of interest because of its zoonotic potential, ability to introduce cDNA of its RNA transcripts into host genomes, and ability to cause severe neurobehavioural diseases. Classical Borna disease is a progressive meningoencephalomyelitis in horses and sheep, known in central Europe for centuries. According to current knowledge, BDV or a close relative also infects several other species, including humans at least occasionally, in central Europe and elsewhere, but the existence of potential 'human Borna disease' with its suspected neuropsychiatric symptoms ...
Marqués FJ, Sharma A, Wilson DG.Advanced diagnostic imaging and histopathological investigation were performed in an adult horse with chronic facial swelling due to a bone sequestrum and abscessation. In contrast to other cases, there were no draining tracts, difficulty eating, weight loss, head shaking, or fistula formation between the oral cavity and the maxillary sinus. Une investigation d’imagerie diagnostique avancée et un examen histopathologique ont été réalisés chez un cheval adulte présentant de l’enflure faciale chronique attribuable à un séquestre osseux et à une abcédation. Par contraste à d’aut...
Silva MA, Silva KM, Jesus AL, Barros LO, Corteggio A, Altamura G, Borzacchiello G, Freitas AC.Papillomavirus (PV) are double-stranded DNA viruses that can cause both benignant and malignant tumours in mammals. Twelve genotypes of bovine papillomavirus (BPV1-12) have been identified so far. The presence of BPV1 and 2 has been found in the body fluids of cattle and horses. The aim of this study is to investigate the presence of BPV DNA and the expression of viral genes in the blood and sperm cells of healthy horses using PCR and RT-PCR. BPV-1 or 2 was detected in 14 of 70 blood samples (20%) and in 11 of 31 semen samples (35%). In five of fourteen blood samples, the E5 expression tested ...
Erridge ME, Cox AL, Dixon PM.Peripheral caries of equine cheek teeth is a poorly described disorder and, in particular little is known of its histopathology. Histological examinations of decalcified sections of 21 equine peripheral caries-affected cheek teeth showed two different patterns of cemental lesions; including progressive enlargement of focal, flask-like lesions leading to breakdown of the adjacent cementum, and secondly; a more generalized flaking-off of thin layers of under-run, surface cementum. A thick layer of plaque and food material usually lay on the surface of affected cementum and also within cemental d...
Soares SC, Trost E, Ramos RT, Carneiro AR, Santos AR, Pinto AC, Barbosa E, Aburjaile F, Ali A, Diniz CA, Hassan SS, Fiaux K, Guimarães LC....Corynebacterium pseudotuberculosis is the causative agent of several veterinary diseases in a broad range of economically important hosts, which can vary from caseous lymphadenitis in sheep and goats (biovar ovis) to ulcerative lymphangitis in cattle and horses (biovar equi). Existing vaccines against C. pseudotuberculosis are mainly intended for small ruminants and, even in these hosts, they still present remarkable limitations. In this study, we present the complete genome sequence of C. pseudotuberculosis biovar equi strain 258, isolated from a horse with ulcerative lymphangitis. The genome...
Ben Sallem R, Ben Slama K, Sáenz Y, Rojo-Bezares B, Estepa V, Jouini A, Gharsa H, Klibi N, Boudabous A, Torres C.The prevalence of extended-spectrum beta-lactamase (ESBL)- and plasmidic AmpC-beta-lactamase (pAmpC-BL)-producing Escherichia coli isolates has been studied in food-producing animals at the farm level in Tunisia, and recovered isolates were characterized for the presence of other resistance genes and integrons. Eighty fecal samples of food-producing animals (23 sheep, 22 chickens, 22 cattle, six horses, five rabbits, and two dromedaries) were obtained from 35 different farms in Tunisia in 2011. Samples were inoculated onto MacConkey agar plates supplemented with cefotaxime (2 mg/L) for cefot...
Grause JF, Ueti MW, Nelson JT, Knowles DP, Kappmeyer LS, Bunn TO.Theileria equi, one of the causative agents of equine piroplasmosis, is endemic in many regions of the world but is considered a 'foreign' animal disease in the USA. In an effort to prevent the importation of T. equi, stringent serological screening of horses is practiced prior to entry to the USA. Current regulatory options available where horses are found to be infected include permanent quarantine with or without chemotherapy, repatriation, or euthanasia. Chemotherapeutics that eliminate infection and subsequently transmission risk are critical in the management of infected horses. In this ...
Inácio SV, de Brito RL, Zucatto AS, Coelho WM, de Aquino MC, Aguirre Ade A, Perri SH, Meireles MV, Bresciani KD.The present study aimed to analyze the occurrence of infection by Cryptosporidium spp. in mares and their respective foals. This study was carried out in 11 farms located in the municipalities of Araçatuba, Birigui, Guararapes and Santo Antônio do Aracangua, in the northwest region of the State of Sao Paulo, from November 2010 to March 2011. A total of 98 mares and 98 foals of several breeds were analyzed; among foals, 59 were males and 39 females, aged from three to 330 days. Feces were collected directly from the rectal ampulla, purified and processed according to modified Kinyoun stain. O...
Hahn S, Giaglis S, Hoesli I, Hasler P.The intention of this review is to provide an overview of the potential role of neutrophil extracellular traps (NETs) in mammalian reproduction. Neutrophil NETs appear to be involved in various stages of the reproductive cycle, starting with fertility and possibly ending with fetal loss. The first suggestion that NETs may play a role in pregnancy-related disorders was in preeclampsia, where vast numbers were detected in the intervillous space of affected placentae. The induction of NETosis involved an auto-inflammatory component, mediated by the increased release of placental micro-debris in p...
Hartig W, Houe H, Andersen PH.The plentiful data on Danish horses are currently neither organized nor easily accessible, impeding register-based epidemiological studies on Danish horses. A common database could be beneficial. In principle, databases can contain a wealth of information, but no single database can serve every purpose. Hence the establishment of a Danish equine health database should be preceded by careful consideration of its purpose and content, and stakeholder attitudes should be investigated. The objectives of the present study were to identify stakeholder attitudes to the importance, purpose, research ar...
Schwaber MJ, Navon-Venezia S, Masarwa S, Tirosh-Levy S, Adler A, Chmelnitsky I, Carmeli Y, Klement E, Steinman A.Methicillin-resistant Staphylococcus aureus (MRSA) infection or colonization has become a serious emerging condition in equine hospitals. Following the detection of MRSA in asymptomatic hospitalized horses and in two horses with post-operative wound infections, an investigation was conducted. Twelve of 84 horses (14.3%) and 16 of 139 personnel (11.5%) were MRSA carriers. The profile of the dominant MRSA strain common to horses and staff was multi-drug-resistant, spa-type t535, SCCmec type V, pvl-negative. MLST of a representative isolate yielded sequence type (ST) 5. The risk of MRSA carriage ...
Lynch SE, Gilkerson JR, Symes SJ, Huang JA, Hartley CA.Equine rhinitis A virus (ERAV) is a member of the Aphthovirus genus, and has many physical and structural similarities to the prototype Aphthovirus foot-and-mouth disease virus (FMDV). The pathogenesis of FMDV has been extensively studied, however, the similarities in the pathogenesis of ERAV and FMDV disease has not been well documented. This study describes and compares the pathogenesis of ERAV both in the natural host and a small animal model alternative (CBA mice). Distinct parallels in the pathogenesis of the acute infection of these two viruses are described where infection in the upper ...
Diaz-Méndez A, Viel L, Shewen P, Nagy E.Equine rhinitis A virus (ERAV) is an ubiquitous virus, routinely identified in equine respiratory infections; however, its role in disease and genetic features are not well defined due to a lack of genomic characterization of the recovered isolates. Therefore, we sequenced the full-length genome of a Canadian ERAV (ERAV/ON/05) and compared it with other ERAV sequences currently available in GenBank. The ERAV/ON/05 genome is 7,839 nucleotides (nts) in length with a variable 5'UTR and a more conserved 3'UTR. When ERAV/ON/05 was compared to other reported ERAV isolates, an insertion of 13 nt in t...
Lyons S, Kapoor A, Sharp C, Schneider BS, Wolfe ND, Culshaw G, Corcoran B, McGorum BC, Simmonds P.Although the origin of hepatitis C virus infections in humans remains undetermined, a close homolog of this virus, termed canine hepacivirus (CHV) and found in respiratory secretions of dogs, provides evidence for a wider distribution of hepaciviruses in mammals. We determined frequencies of active infection among dogs and other mammals in the United Kingdom. Samples from dogs (46 respiratory, 99 plasma, 45 autopsy samples) were CHV negative by PCR. Screening of 362 samples from cats, horses, donkeys, rodents, and pigs identified 3 (2%) positive samples from 142 horses. These samples were gene...
Soykan E, Oge H.This study was carried out between March 2004- April 2005 to determine the prevalance of liver trematode infections of equids in different cities of Turkey. Methods: A total of 117 equids (72 horses, 39 donkeys and 6 mules) in Ankara were examined for liver parasites after the slaugthering process. On the other hand, a total of 620 feces of horses in Bursa, Gemlik, Malatya, Eskişehir and Ankara provinces were detected for determining liver trematodes in live equines. The fecal samples of horses were examined for liver fluke infection by Benedect's sedimentation methods. Results: Of these 117 ...
Dallap Schaer BL, Linton JK, Aceto H.Recommendations for antimicrobial prophylaxis for surgery are well-described in human medicine, but information is limited for veterinary practice. Objective: To characterize antimicrobial use in horses undergoing emergency colic surgery. Methods: A total of 761 horses undergoing emergency colic surgery (2001-2007). Methods: Retrospective case review. Antimicrobial dose and timing, surgical description, and duration of treatment were collected from medical records. Associations between antimicrobial use and the occurrence of fever, incisional inflammation or infection, catheter-associated comp...
Fukushi H, Yamaguchi T, Yamada S.Equine herpesvirus type 9 (EHV-9), which we isolated from a case of epizootic encephalitis in a herd of Thomson's gazelles (Gazella thomsoni) in 1993, has been known to cause fatal encephalitis in Thomson's gazelle, giraffe, and polar bear in natural infections. Our previous report indicated that EHV-9 was similar to the equine pathogen equine herpesvirus type 1 (EHV-1), which mainly causes abortion, respiratory infection, and equine herpesvirus myeloencephalopathy. We determined the genome sequence of EHV-9. The genome has a length of 148,371 bp and all 80 of the open reading frames (ORFs) fo...
Meng Q, Lin Y, Ma J, Ma Y, Zhao L, Li S, Yang K, Zhou J, Shen R, Zhang X, Shao Y.Data from successful attenuated lentiviral vaccine studies indicate that fully mature Env-specific antibodies characterized by high titer, high avidity, and the predominant recognition of conformational epitopes are associated with protective efficacy. Although vaccination with a DNA prime/recombinant vaccinia-vectored vaccine boost strategy has been found to be effective in some trials with non-human primate/simian/human immunodeficiency virus (SHIV) models, it remains unclear whether this vaccination strategy could elicit mature equine infectious anemia virus (EIAV) Env-specific antibodies, ...
Yadav SC, Kumar R, Manuja A, Goyal L, Gupta AK.In present communication, we report an outbreak of Trypanosoma evansi in equine herd n = 30 (horse and mules) which, were reared in fly proof stables as well as in open paddock maintained under semi-intensive system of management, and its effective control using trypanocidal drug. The infection was monitored by antibody ELISA up to 180 days post-treatment (PT). A total of 8 out of 14 equines (57.14 %) which were maintained only in open paddocks were found positive with T. evansi infection parasitologically. The infected animals were treated with quinapyramine methyl sulphate and chloride c...
Divers TJ, Grice AL, Mohammed HO, Glaser AL, Wagner B.Changes in ELISA serology are frequently used to determine antibiotic treatment success for Lyme disease in horses. This concept was based upon a previous report showing a marked decline in ELISA values in experimentally infected and antibiotic-treated ponies. Changes in Lyme serology following antibiotic treatment in naturally infected horses have not been reported. The objective of this study was to compare Borrelia ELISA antibody concentrations in naturally exposed horses both before and following antibiotic treatment for Lyme disease. A retrospective study was performed comparing oxytetrac...
Mc Nally TP, Slone DE, Hughes FE, Lynch TM.To describe a tenosynoviotomy technique for treatment of sepsis of the digital flexor tendon sheath (DFTS) in horses and report long-term outcome. Methods: Case series. Methods: Horses (n = 9). Methods: Horses were positioned in lateral recumbency with the affected limb uppermost. A linear incision was made just lateral to the mesotenon beginning 5 cm proximal to the apices of the proximal sesamoid bones, extending 2 cm distal to the bifurcation of the superficial digital flexor tendon (SDFT). The incision was continued through the skin, subcutaneous tissue, palmar/plantar annular ligament, an...
Tydén E, Morrison DA, Engström A, Nielsen MK, Eydal M, Höglund J.The large roundworm of horses, Parascaris equorum is considered ubiquitous in breeding operations, and is regarded as a most important helminth pathogen of foals. Over the past decade, this parasite has been reported increasingly resistant to anthelmintic drugs worldwide. This paper reports analysis of the population genetic structure of P. equorum. Adult parasites (n=194) collected from Sweden, Norway, Iceland, Germany, Brazil and the USA were investigated by amplified restriction fragment length polymorphism (AFLP) analysis. The genetic variation was low (Hj=0.12-0.4), for the global populat...
Cavanagh HM, Mahony TJ, Vanniasinkam T.Two known serotypes of equine adenovirus (EAdV), equine adenovirus type 1 (EAdV-1) and equine adenovirus type 2 (EAdV-2) have been isolated from horses. EAdV-1 is predominantly associated with upper respiratory tract infections while EAdV-2 appears to be associated with gastrointestinal infections in horses. In this report the EAdV-1 genome has been sequenced for the first time. The EAdV-1 genome encoded genes are characteristic of the Mastadenovirus genus such as protein V and IX. Unexpectedly, phylogenetic reconstructions also revealed a close relationship between EAdV-1 and two recently cha...
Williams DL, Issel CJ, Steelman CD, Adams WV, Benton CV.Biological and mechanical transmission trials with Psorophora columbiae (Dyar and Knab) and Aedes sollicitans (Walker) and ponies acutely infected with equine infectious anemia virus (EIAV) were negative. The EIAV antigen was detected by radioimmunoassay in Ae sollicitans immediately after the mosquitoes had fed on an acutely ill pony, but not 14 days after feeding. Psorophora columbiae mosquitoes had detectable EIAV antigen as determined by radioimmunoassay 24 hours after they fed on an acutely ill pony; this antigen was not detected again until 6 days after feeding and was still detected 14 ...
Dilai M, Piro M, El Harrak M, Fougerolle S, Dehhaoui M, Dikrallah A, Legrand L, Paillot R, Fassi Fihri O.To evaluate the humoral immune response to mixed Equine Influenza vaccination, a common practice in the field, an experimental study was carried out on 42 unvaccinated thoroughbred weanling foals divided into six groups of seven. Three groups were vaccinated using a non-mixed protocol (Equilis Prequenza-Te, Proteqflu-Te or Calvenza-03) and three other groups were vaccinated using a mix of the three vaccines mentioned previously. Each weanling underwent a primary EI vaccination schedule composed of two primary immunisations (V1 and V2) four weeks apart followed by a third boost immunisation (V3...
Hellman S, Hjertner B, Morein B, Fossum C.The immunomodulatory effect of a new particulate adjuvant, G3, alone or in combination with agonists to TLR2/1 or TLR5 was evaluated in cultures of equine PBMC. Exposure to the G3 adjuvant up-regulated genes encoding IFN-γ, IL-1β, IL-6, IL-8, IL-12p40 and IL-23p19 in the majority of the horses tested, indicating that the G3 adjuvant induced a pro-inflammatory and Th1 dominated profile. In accordance, genes encoding IL-13, IL-4, IL-10 and TGF-β remained unaffected and genes encoding IFN-α, IL-17A and TNF-α were only occasionally and weakly induced. The two TLR agonists Pam3CSK4 (TLR2/1) an...
Xie J, Liu G, Tian Z, Luo J.Several approaches have been developed for diagnosis of Theileria equi infection in horses and donkeys but all of them have limitations in practice. Due to numerous strengths including easy operation, cheapness and high sensitivity and specificity, LAMP has been already extensively used for surveillance of a number of diseases. We here set up a LAMP assay based on 18S rRNA gene for T. equi diagnosis. The approach was specific enough to differentiate T. equi from other evolutionary-related protozoa. Moreover, it was sensitive enough that LAMP was capable of detecting as much low as 10 copy targ...
Gummery L, Jallow S, Raftery AG, Bennet E, Rodgers J, Sutton DGM.Infection of equids with Trypanosoma brucei (T. brucei) ssp. is of socioeconomic importance across sub-Saharan Africa as the disease often progresses to cause fatal meningoencephalitis. Loop-mediated isothermal amplification (LAMP) has been developed as a cost-effective molecular diagnostic test and is potentially applicable for use in field-based laboratories. Threshold levels for T. brucei ssp. detection by LAMP were determined using whole equine blood specimens spiked with known concentrations of parasites. Results were compared to OIE antemortem gold standard of T. brucei-PCR (TBR-PCR). Th...
Sparks WO, Dorman KS, Liu S, Carpenter S.Equine infectious anemia virus (EIAV) exhibits a high rate of genetic variation in vivo, and results in a clinically variable disease in infected horses. In vivo populations of EIAV have been characterized by the presence of distinct, genetic subpopulations of Rev that differ in phenotype and fluctuate in dominance in a manner coincident with each clinical stage of disease. This study examined the specific mutations that arose in vivo and altered the phenotype. The Rev protein was found to be highly conserved, and only 10 aa mutations were observed at a frequency greater than 10 % in the sampl...
Timonin ME, Poissant J, McLoughlin PD, Hedlin CE, Rubin JE.The feral horses of Sable Island are a geographically isolated population located ∼160 km off the east coast of Nova Scotia, Canada. Because these horses have no contact with domestic animals, have minimal contact with people, and have never received antimicrobials, they offer a unique opportunity to study the dissemination of antimicrobial resistance in unmanaged populations. As part of an ongoing multidisciplinary and individual-based monitoring program, we collected feces from 508 geolocalized horses (92% of the total population) between July and September 2014. We selectively cultured Es...
Berg AL, Dörries R, Berg M.Borna disease virus (BDV) is a neurotropic agent with capacity to infect and cause neurological disease in a broad range of warmblooded hosts including horses, sheep, cattle, cats, and possibly also humans. The epidemiology of BDV is largely unknown. However, it is likely that subclinically infected animals may represent potential virus reservoirs. In two groups of Swedish racing horses, one clinically healthy and one consisting of horses with diffuse neurological signs, the BDV seroprevalence was 24.5% and 57.7%, respectively. BDV RNA was detected in peripheral blood mononuclear cells in 8 ou...
Shnaiderman-Torban A, Marchaim D, Navon-Venezia S, Lubrani O, Paitan Y, Arielly H, Steinman A.In human medicine, infections caused by third-generation cephalosporin-resistant (3GCRE) are associated with detrimental outcomes. In veterinary medicine, controlled epidemiological analyses are lacking. A matched case-case-control investigation (1:1:1 ratio) was conducted in a large veterinary hospital (2017-2019). In total, 29 infected horses and donkeys were matched to 29 animals with third-generation cephalosporin-susceptible (3GCSE) infections, and 29 uninfected controls (overall = 87). Despite multiple significant associations per bivariable analyses, the only independent predictor fo...
Son WG, Lee DS, Yamatoda N, Hatori F, Shimizu N, Kakuda T, Sasaki Y, Tsubaki S, Takai S.We recently demonstrated the presence of virulence-associated protein antigen (VapA)-positive Rhodococcus equi in Jeju Island, Korea. These bacteria contained one of two distinct plasmid types, a 90-kb type II plasmid, which has been found in isolates from the native Kiso horses of Japan, and a new variant, a 90-kb type V plasmid. However, the genotypic characters of the VapA-positive R. equi from Jeju native horses and their environments are poorly understood. Ninety-eight isolates from soil samples and 89 isolates from fecal samples were collected from five farms that breed or have bred Jeju...
Schoenbaum MA, Hall SM, Glock RD, Grant K, Jenny AL, Schiefer TJ, Sciglibaglio P, Whitlock RH.A USDA Early Response Team investigated deaths of several horses and a mule in northern Arizona at the request of local animal health officials. Thirteen animals (12 horses and 1 mule) housed at 5 facilities in a 7.4 square mile area died between August 1998 and January 1999. Clinical signs consisted of muscular weakness that rapidly progressed to lateral recumbency. Ten animals had paresis of the tongue, throat, or lips. Affected animals appeared alert and were interested in eating and drinking, even while recumbent. All 13 animals were euthanatized. Clostridium botulinum type C was isolated ...
Shimizu C, Shibahara T, Takai S, Kasuya K, Chikuba T, Murakoshi N, Kobayashi H, Kubo M.A 26-month-old thoroughbred colt with a 4-month history of continuous diarrhoea and weight loss was subject to necropsy examination. The small intestinal mucosa was thickened and this change particularly affected the terminal ileum. Microscopical examination revealed multifocal epithelial hyperplasia, with multifocal granulomas and marked lymphocytic infiltration of the lamina propria. Numerous gram-negative argyrophilic curved bacilli were observed within the cytoplasm of affected enterocytes. Macrophages and epithelioid cells forming the granulomas had abundant, lightly eosinophilic, foamy c...
Van Duijkeren E, Vulto AG, Van Miert AS.The indications for use, side-effects, and pharmacokinetic parameters of trimethoprim, sulfonamides and their combinations in the horse are reviewed. Trimethoprim/sulfonamide (TMPS) combinations are used for the treatment of various diseases caused by gram-positive and gram-negative bacteria, including infections of the respiratory tract, urogenital tract, alimentary tract, skin joints and wounds. TMPS combinations can be administered orally, since absorption from the gastrointestinal tract is relatively good. However, peak serum concentrations can vary significantly between individual horses....
Stockton KA, Morley PS, Hyatt DR, Burgess BA, Patterson G, Dunowska M, Lee DE.To evaluate the effects of footwear hygiene protocols on bacterial contamination of floor surfaces in an equine hospital. Methods: Field trial. Methods: Footwear hygiene protocols evaluated included use of rubber overboots with footbaths and footmats containing a quaternary ammonium disinfectant, rubber overboots with footbaths and footmats containing a peroxygen disinfectant, and no restrictions on footwear type but mandatory use of footbaths and footmats containing a peroxygen disinfectant. Nonspecific aerobic bacterial counts were determined via 2 procedures for sample collection and bacter...
Hines R, Sorensen BR, Shea MA, Maury W.Binding of the transcription factor PU.1 to its DNA binding motif regulates the expression of a number of B-cell- and myeloid-specific genes. The long terminal repeat (LTR) of macrophage-tropic strains of equine infectious anemia virus (EIAV) contains three PU.1 binding sites, namely an invariant promoter-proximal site as well as two upstream sites. We have previously shown that these sites are important for EIAV LTR activity in primary macrophages (W. Maury, J. Virol. 68:6270-6279, 1994). Since the sequences present in these three binding motifs are not identical, we sought to determine the r...
Dieckmann SM, Hoelzle K, Dieckmann MP, Straube I, Hofmann-Lehmann R, Hoelzle LE.Hemotrophic mycoplasmas (HM) are small, cell wall-less bacteria and infections are known for a wide range of animals. One possible indication of equine HM infection was given in 1978, when a 'haemobartonellosis' outbreak was diagnosed in Nigerian horses by microscopy. However the first molecular proof of HM in horses was not reported until 2010, when a fragment of about 900 bp of the 16S rRNA of the equine HM was obtained. This sequence was used for the development of a SYBR green I real-time PCR assay specific for equine HM. The lower detection limit of the PCR was ten 16S rDNA copy numbers p...
Hu Y, Jia Q, Liu J, Sun W, Bao Z, Che C, Wu G, Fan B, Jarhen , Ran D.Equid alphaherpesvirus 1 (EHV-1) is prevalent in China, and causes notable economic damage to the equine industry. However, there is no information regarding the molecular characteristics and pathogenicity of the Chinese strains. Therefore, an EHV-1 strain, named YM2019, was isolated from the lung tissue of an aborted horse fetus in Xinjiang, China, and its genome and pathogenicity were analyzed. The full genome of the isolate was 150,267 base pairs in length, with 56.7% G + C content. Genetic and phylogenetic analysis showed that strain YM2019 (GenBank: MT063054) belonged to the ORF30 N75...
Rimstad E, Evensen O.Paraffin-embedded organ samples from 28 aborted fetuses and three foals, partly archival and partly sampled in 1991, were examined by polymerase chain reaction (PCR) and immunohistochemistry for the presence of DNA and antigens, respectively, specific for equine herpesvirus 1 (EHV-1). Virologic examination had been performed on 23 of the aborted fetuses. DNA fragments specific for EHV-1 were identified by PCR, and EHV-1 antigens were identified in situ by immunohistochemistry, with an agreement between the methods of 94% (kappa = 0.85). Compared with virus isolation, PCR agreement was 87% (kap...
Durham AE, Kemp-Symonds J.Serology is commonly used as a means of identifying horses that might be chronic and silent carriers of S. equi but its sensitivity is rarely examined. Objective: The study was designed to investigate the sensitivity of serological testing for antibodies against S. equi antigens A and C to detect guttural pouch carriers of S. equi. Methods: Retrospective clinical study. Methods: As part of routine surveillance and quarantine procedures horses arriving at a welfare charity quarantine unit were subject to both microbiological sampling of guttural pouches and also serological testing for antibo...
Eysker M, Boersema JH, Kooyman FN.Two groups of three yearling Shetland ponies were used in 1988 to study the epidemiological significance of inhibited development of the Cyathostomine nematodes. In Group 1, acquisition of infections was prevented throughout the grazing season whereas in Group 2 strongylid infections were acquired from the beginning of July until the end of September. Worm counts showed that the Cyathostomine nematode populations of Group 1 ponies mainly consisted of adult worms and those of Group 2 ponies of inhibited early third stage larvae (L3). These results indicate that a large proportion of Cyathostomi...
Jaramillo-Morales C, Gomez DE, Renaud D, Arroyo LG.The objectives of this study were to determine the prevalence of S. equi in a horse population in Colombia, to determine the risk factors associated with its detection in the guttural pouches and to report the antimicrobial susceptibility of the isolates. Fifteen farms and 137 horses >6 months of age were enrolled. Sampling was randomly, stratified and proportional to the population size of each farm. The guttural pouch (GP) was swabbed via endoscopic guidance and culture was performed. DNA extraction and conventional PCR were performed in colonies compatibles with S. equi, the PCR products we...
Fielding CL, Pusterla N, Magdesian KG, Higgins JC, Meier CA.To characterize signalment, clinical and laboratory findings, treatment, and outcome in horses with rattlesnake envenomation in northern California. Methods: Retrospective case series. Methods: 58 client-owned horses evaluated for rattlesnake envenomation at 2 referral hospitals from 1992 to 2009. Methods: Records of horses with rattlesnake envenomation were reviewed, and data concerning signalment, clinical and laboratory findings, treatment, and outcome were collected. In addition, a rattlesnake-bite severity score (RBSS) was assigned to each horse. Variables were compared between horses tha...
Tscheschlok L, Venner M, Howard J.Failure of transfer of passive immunity (FTPI) in foals is associated with a risk of infection and death. The current diagnostic gold standard is quantification of immunoglobulins using radial immunodiffusion (IgG-RID). Routine diagnosis is often performed using semi-quantitative tests. Concentrations of serum electrophoretic gamma globulins (EGG) and total globulins may be useful to assess FTPI, but few studies have investigated their use. Objective: To assess agreement between IgG-RID and EGG and evaluate the accuracy of total globulin concentration to diagnose FTPI based on both IgG-RID and...
Jacks S, Giguère S.The objective of this pilot study was to compare the cytokine profile as well as cell-mediated and antibody responses of foals infected with a low inoculum of virulent Rhodococcus equi resulting in subclinical pneumonia to that of foals infected with a high inoculum resulting in severe clinical pneumonia. The mean (+/-SD) ratio of post-infection to pre-infection anti-R. equi IgG(T) concentration was significantly (P=0.002) higher in foals infected with the high inoculum (195+/-145; range 62-328) compared to foals infected with the low inoculum (3.9+/-4.5; range 0.5-11). Similarly, mean (+/-SD)...
Lichtenstein DL, Craigo JK, Leroux C, Rushlow KE, Cook RF, Cook SJ, Issel CJ, Montelaro RC.The long terminal repeat (LTR) is reported to be one of the most variable portions of the equine infectious anemia virus (EIAV) genome. To date, however, no information is available on the effects of observed sequence variations on viral replication properties, despite a widespread assumption of the biological importance of EIAV LTR variation. EIAV LTR sequence variability is confined mostly to a small portion of the enhancer within the U3 segment of the LTR. Analysis of published EIAV LTR sequences revealed six different types of LTR based on the pattern of putative transcription factor motif...
La Perle KM, Piercy RJ, Long JF, Blomme EA.Multisystemic, eosinophilic, epitheliotropic disease and intestinal lymphosarcoma were diagnosed in a Paso Fino mare that presented with anorexia and weight loss. The stomach, ileum, cecum, colon, pancreas, and lungs were infiltrated by large numbers of eosinophils forming prominent eosinophilic granulomas, as well as lymphocytes and plasma cells. Two jejunal masses composed of solid sheets of neoplastic lymphocytes were present. In contrast to the regions of inflammation, the infiltrates in these masses did not contain plasma cells, eosinophils, and eosinophilic granulomas. Immunohistochemica...
Perelygin AA, Zharkikh AA, Astakhova NM, Lear TL, Brinton MA.Chemokine receptors (CCRs) play an essential role in the initiation of an innate immune host response. Several of these receptors have been shown to modulate the outcome of viral infections. The recent availability of complete genome sequences from a number of species provides a unique opportunity to analyze the evolution of the CCR genes. A phylogenetic analysis revealed that the CCR2 gene evolved in concert with the paralogous CCR5 gene, but not with another paralogous gene, CCR3, in the opossum, platypus, rabbit, guinea pig, cat, and rodent lineages. In addition, evidence of concerted evolu...
Boyle AG, Boston RC, O'Shea K, Young S, Rankin SC.Streptococcus equi is the etiologic agent of a highly infectious upper respiratory disease of horses known as strangles. Bacterial culture methods and polymerase chain reaction (PCR) of nasopharyngeal washes and guttural pouch lavages are used routinely to test clinical and carrier animals for the presence of S. equi but no definitive or gold standard test method has been shown to be optimal. We hypothesized that (i) a flocked swab submerged in ten-fold serial dilution suspensions of S. equi prepared in 0.9% NaCl would detect more colony forming units (CFU) than a rayon swab when used to inocu...
Gruber J.Purified and concentrated Venezuelan equine encephalitis (VEE) virus derived from tissue cultures, rendered noninfectious by ionizing radiation with retention of in vitro serological activity, also retained a high level of immunogenicity. In mice, fluid vaccines afforded excellent protection against lethal challenge with homologous Trinidad strain VEE virus. A direct relationship was observed between concentration of vaccine or number of injections and survival. One intraperitoneal inoculation of undiluted vaccine protected essentially all mice challenged 21 days later with 100,000 mouse intra...
