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.
Jackson M, Kummer M, Auer J, Hagen R, Fuerst A.This prospective study describes a series of 18 olecranon fractures in 16 horses that were treated with locking compression plates (LCP). Twelve of the 18 fractures were simple (type 2), whereas six were comminuted (type 4). Six fractures were open and 12 were closed. Each horse underwent LCP osteosynthesis consisting of open reduction and application of one or two LCP. Complete fracture healing was achieved in 13 horses. Three horses had to be euthanatized: two because of severe infection and one because of a comminuted radial fracture 11 days after fixation of the olecranon fracture. Complic...
Hall TL, Tell LA, Wetzlich SE, McCormick JD, Fowler LW, Pusterla N.Ceftiofur, a third generation cephalosporin, demonstrates in vitro efficacy against microorganisms isolated from septicemic neonatal foals. This pharmacokinetic study evaluated the intravenous and subcutaneous administration of ceftiofur sodium (5 mg/kg body weight; n = 6 per group) and subcutaneous administration of ceftiofur crystalline free acid (6.6 mg/kg body weight; n = 6) in healthy foals. Plasma ceftiofur- and desfuroylceftiofur-related metabolite concentrations were measured using high performance liquid chromatography following drug administration. Mean (±SD) noncompartmental pharma...
Forbes G, Church S, Savage CJ, Bailey SR.Endotoxaemia is a major cause of equine morbidity, and plasma from horses immunised against Escherichia coli is used in its treatment. The aim of this study was to determine the effects of hyperimmune plasma on the clinical and leukocyte responses, including production and activity of TNFα, in an in vivo endotoxin challenge model. Pre-treatment with hyperimmune equine plasma had no significant effect on peak total plasma TNFα concentration (occurring 90min after the administration of 30ng/kg LPS). However, the bioavailable (unbound) TNFα measured by bioassay was significantly reduced in pla...
Carstanjen B, Boehart S, Cislakova M.Septic arthritis in horses is a serious disease which can become life-threatening. In case the infection can be eliminated before irreversible joint damage occurs, complete recovery is possible. This article gives an overview of the literature concerning etiology, diagnosis and strategies of therapy in cases of septic arthritis in adult horses, with special reference to novel options of treatment.
James FM, Engiles JB, Beech J.A 12-year-old Thoroughbred was examined because of signs of depression, neck stiffness, and poor performance. Results: Physical examination revealed that the horse was dull, appeared depressed, was reluctant to raise its neck and head above a horizontal plane, and had a temperature of 38.5°C (101.3°F). No radiographic or scintigraphic abnormalities of the neck were found; however, high plasma fibrinogen concentration and relative lymphopenia were identified and the horse was seropositive for antibodies against Borrelia burgdorferi. Analysis of CSF revealed neutrophilic inflammation, and resu...
Campos RK, Brum MC, Nogueira CE, Drumond BP, Alves PA, Siqueira-Lima L, Assis FL, Trindade GS, Bonjardim CA, Ferreira PC, Weiblen R, Flores EF....During the last bovine vaccinia (BV) outbreaks, several Vaccinia virus (VACV) strains were isolated and characterised, revealing significant polymorphisms between strains, even within conserved genes. Although the epidemiology of VACV has been studied in BV outbreaks, there is little data about the circulation of the Brazilian VACV isolates. This study describes the genetic and biological characterisation of two VACV isolates, Pelotas 1 virus (P1V) and Pelotas 2 virus (P2V), which were obtained concomitantly from a horse affected by severe cutaneous disease. Despite being isolated from the sam...
Farr AC, Hawkins JF, Baird DK, Moore GE.To characterize features of diagnosis, treatment, and outcome in horses with foreign bodies, exclusive of enteric, inhaled, and foot-penetrating foreign bodies. Methods: Retrospective case series. Methods: 37 horses with foreign bodies. Methods: The incidence of equine foreign bodies from 1990 through 2005 was determined by review of data from veterinary schools participating in the Veterinary Medical Database (VMDB). Medical records of horses with foreign bodies at Purdue University were reviewed, and the following information was retrieved: clinical history; signalment; results of physical, ...
Yeargan MR, Howe DK.Equine protozoal myeloencephalitis (EPM) is a common neurologic disease of horses that is caused by the apicomplexan pathogen Sarcocystis neurona. To help improve serologic diagnosis of S. neurona infection, we have modified existing enzyme-linked immunosorbent assays (ELISAs) based on the immunogenic parasite surface antigens SnSAG2, SnSAG3, and SnSAG4 to make the assays polyvalent, thereby circumventing difficulties associated with parasite antigenic variants and diversity in equine immune responses. Two approaches were utilized to achieve polyvalence: (1) mixtures of the individual recombin...
Monini M, Biasin A, Valentini S, Cattoli G, Ruggeri FM.A total of 47 stool samples were collected at the same stud farm from young foals with rotavirus diarrhoea and from their stud mares. Illness involved foals during three consecutive winter seasons. Infection in the farm appeared firstly in January-February 2008. After vanishing in the warm seasons, cases reappeared in March 2009 and 2010. Determination of the rotavirus G- and P-types was carried out using nested RT-PCR in samples collected in 2009 and 2010. A total of 19 of 47 samples resulted positive for rotavirus. The G type was determined in 19/47 samples, whereas the P genotype was determ...
Wauters J, Martens A, Pille F, Dumoulin M, Gasthuys F, Sys S, Meyer E.Synovial fluid samples from culture-confirmed infected joints (n=13), joints with pronounced non-infectious synovitis (n=11) and healthy joints (n=14) were collected from 24 equine patients and seven slaughterhouse horses. The samples from the joints with non-infectious synovitis and healthy joints served as negative controls. After isolation, counting and identification of neutrophils, the percentage viability, and the proportion apoptotic and necrotic neutrophils were determined by flow cytometry. Viability was significantly higher in infected samples compared to the controls. A significant ...
Schoster A, Anderson ME.A 9-year-old Quarter horse was presented for chronic refractory pneumonia. On necropsy, an hepatic abscess, caudal vena cava thrombosis, pulmonary thromboembolism, and embolic pneumonia were identified. Similar lesions have been reported in cattle as caudal vena cava thrombosis syndrome, however this syndrome has not previously been reported in horses. Un cheval Quarter horse âgé de 9 ans est présenté pour une pneumonie réfractaire chronique. À la nécropsie, un abcès hépatique, une thrombose de la veine cave caudale, un thromboembolisme pulmonaire et une pneumonie embolique ont été...
Zaleska M, Anusz K, Winnicka A, Kita J.Twelve horses, all of them 10 years old, were vaccinated intramuscularly on 0 and 28 days of the experiment with inactivated vaccine containing only antigens of A-equi-2/Miami/63. Another three unvaccinated horses, each at the age of 10 years, were the negative control group. One, ten-year-old horse was vaccinated with commercial inactivated vaccine containing both antigens of A-equi-2/Miami/63 as well as A-equi-1/Praha/56 as positive control. Three horses were challenged intranasally with homotypic strain of Miami/63, while six other were challenged with heterotypic strains--three with Suffol...
Urosevic M, Lako B, Milanov D, Urosevic I, Aurich C.Uterine microbiology, antimicrobial susceptibility and endometrial cytology were investigated in a total of 51 mares with fertility problems from 16 different stud farms in Serbia. Uterine cultures were performed after collection with a double guarded uterine swab, and endometrial cytology was evaluated after collection of endometrial cells with a special device (cytology brush). In 21 of 51 mares, at least one bacterial species was isolated from the uterus; the most frequent were Streptococcus equi subsp. zooepidemicus (13 isolates) and E. coli (four isolates). All isolates of Streptococcus e...
Pusterla N, Conrad PA, Packham AE, Mapes SM, Finno CJ, Gardner IA, Barr BC, Ferraro GL, Wilson WD.Over a 2-yr study period, we investigated possible endogenous transplacental transmission of Neospora hughesi in 74 mare and foal pairs following the diagnosis of neuronal neosporosis in a weanling foal. Presuckle and postsuckle serum of each foal, serum and colostrum of each periparturient mare, and serum of each mare and foal pair, collected at 3-mo intervals thereafter, were tested for N. hughesi using an indirect fluorescent antibody test (IFAT). Furthermore, whole blood and colostrum samples and placentae were tested for the presence of N. hughesi by real-time PCR. The mares' seroprevalen...
Magdesian KG, Leutenegger CM.Clostridium difficile infection can occur in the dams of sick foals, but it is unknown if mares and foals share the same isolates. In this study, C. difficile isolates from fecal samples of 11 mares paired with 11 foals were genotyped by arbitrarily primed PCR; two mares and three foals in five mare-foal pairs had diarrhea. Fecal immunoassays were utilized to detect C. difficile common antigen and toxin A. Quantitative real-time PCR (qPCR) systems were developed to detect genes for toxins A and B, as well as for binary toxin B. Sequences of all toxins were present in all isolates, although onl...
Wilsterman S, Soboll-Hussey G, Lunn DP, Ashton LV, Callan RJ, Hussey SB, Rao S, Goehring LS.Infection with equine herpesvirus-1 (EHV-1) causes respiratory disease, late term abortions and equine herpesvirus myeloencephalitis (EHM) and remains an important problem in horses worldwide. Despite increasing outbreaks of EHM in recent years, our understanding of EHM pathogenesis is still limited except for the knowledge that a cell-associated viremia in peripheral blood mononuclear cells (PBMCs) is a critical link between primary respiratory EHV-1 infection and secondary complications such as late-term abortion or EHM. To address this question our objective was to identify which PBMC subpo...
Pavone S, Veronesi F, Genchi C, Fioretti DP, Brianti E, Mandara MT.In this study, pathological changes caused by Anoplocephala perfoliata in the ileocecal junction were investigated in 31 regularly slaughtered mixed-breed horses of both sexes. Our results showed a significant relationship between parasite burden and grading of histopathological lesions in the mucosa and submucosa. Hypertrophy of the circular muscle layer was found in infected horses. Moreover, enteric nervous system evaluation showed a significant injury of intestinal nervous elements in the horses with moderate to high parasitism expressed as an increase of degenerative-regressive changes in...
Bach BC, Leal DB, Ruchel JB, Souza Vdo C, Maboni G, Dal Pozzo M, Schlemmer KB, Alves SH, Santurio JM.NTPDase (EC 3.6.1.5) occurs in lymphocytes and plays an important role in immune function, in that hydrolyzes extracellular nucleoside tri- and/or diphosphates to form AMP. Pythium insidiosum causes the disease pythiosis, a pyogranulomatous disease of horses, dogs, cattle, cats and humans. Most antifungal drugs are ineffective against this pathogen, and immunotherapy, a treatment approach that relies on the injection of P. insidiosum antigen, has been successfully used in humans and horses to manage this disease. In this study, we investigated NTPDase activity in lymphocytes from rabbits inocu...
Figueredo LA, Cafarchia C, Otranto D.Fungi of the genus Geotrichum are commonly found in the environment and, in some circumstances, they may cause diseases in humans and animals. Although these fungi have been isolated from skin lesions of some animal species, their pathogenic role in horses remains uncertain. With the aim to investigate the role of Geotrichum candidum as etiological agent of dermatomycoses, a retrospective study of 64 horses presenting skin lesions and suspected to have fungal infections was carried out. For each animal, anamnestic data were recorded and fungal culture were performed using hair. Out of 64 cases...
Hobo S, Niwa H, Anzai T, Jones JH.In this study, to evaluate the influence of strangles vaccination on serological test results, we investigated the changes in strangles serum antibody levels in horses after vaccination and subsequent intranasal challenge with S. equi. The horses were vaccinated for strangles with either a component vaccine (Group C) or a live vaccine (Group L). We measured changes in strangles serum antibody levels weekly for 20 weeks after vaccinating horses twice for strangles over a 3-week interval, and for 7 weeks after intranasal challenge with S. equi in the same horses. Serum antibody responses to the ...
Gildea S, Arkins S, Cullinane A.In Ireland, horses may be protected against equine influenza virus (EIV) as a result of natural exposure or vaccination. Current mandatory vaccination programmes are targeted at highly mobile horses. A correlation between antibody levels as measured by single radial haemolysis (SRH) and protective immunity against EIV has been established. Objective: The objective of this study was to determine the susceptibility of selected populations of horses by quantifying their antibodies to EIV. Methods: Blood samples were collected from Thoroughbred weanlings, yearlings, racehorses and broodmares, teas...
Georges KC, Ezeokoli CD, Sparagano O, Pargass I, Campbell M, D'Abadie R, Yabsley MJ.Equine piroplasmosis due to Theileria equi and Babesia caballi is endemic in Trinidad. A case of equine piroplasmosis due to T. equi was diagnosed in a thoroughbred foal at 10h post-partum. A high parasitaemia (63%) of piroplasms was observed in a Wright-Giemsa(®) stained thin blood smear from the foal. In addition, the 18S rRNA gene for Babesia/Theileria was amplified from DNA extracted from the blood of the foal and the mare. Amplified products were subjected to a reverse line blot hybridization assay (RLB), which confirmed the presence of T. equi DNA in the foal. The mare was negative by R...
Carlson KL, Kuskie KR, Chaffin KM, Libal MC, Giguère S, Lawhon SD, Cohen ND.This study determined the antimicrobial activity of tulathromycin against Rhodococcus equi in vitro. Ninety-eight virulent isolates of R. equi from equine clinical cases were examined, of which 20 isolates were macrolide resistant. A custom 96-well antimicrobial susceptibility testing plate was used, allowing 14 additional antimicrobials to be tested against R. equi. Isolates were cultured with various concentrations of antimicrobials, and minimal inhibitory concentration (MIC) values were determined. Tulathromycin was found to have poor activity in vitro against R. equi isolates susceptible o...
Gürellı G, Göçmen B.Hemiprorodon gymnoposthium was investigated in the intestine of horses, found in Cyprus. It was found in four of fifth horses examined and thus had a frequency of appearence of 80%. This study reports for the first time the presence of Hemiprorodon gymnoposthium in the intestine of Equids in Cyprus. In addition, it is the second report from the world. Specimens were found to be similar to the original description on the basis of morphological characters and biometric data.
Gorman JK, Gabriel M, MacLachlan NJ, Nieto N, Foley J, Spier S.This pilot study evaluated protection of an equine autogenous bacterin-toxoid vaccine against Corynebacterium pseudotuberculosis infection. Twenty-four BALB/c mice were inoculated with two doses of bacterin-toxoid vaccine or two injections of a placebo. Clinical, microbiologic, and pathologic outcomes were assessed after intradermal infection with one of two equine-origin C. pseudotuberculosis strains. Mice receiving bacterin-toxoid from fast-growing C. pseudotuberculosis showed significant protection from challenge infection, as evidenced by a higher survival rate, fewer gross and histopathol...
Buzzell GR, Tariq S, Traversa D, Schuster R.The infective larva of the spirurid nematode Habronema muscae, a parasite of houseflies, was measured and specimens fixed in Karnovsky's fluid were examined by scanning electron microscopy. The oral opening contains six teeth and is surrounded by large bilobed dorsal and ventral lips and smaller lateral lips. A pair of amphids lie behind the lateral lips. There are two rows of four cephalic papillae. The body is deeply ridged, both transversely and longitudinally. The caudal end of the worm is studded by small papillae. The position of the anal opening is somewhat ambiguous. These larval morph...
Clode AB.The following article briefly discusses the pathogenesis of infectious keratitis in the horse, followed by discussion of management and pharmacological aspects to be considered when devising a therapeutic protocol for affected patients.
Loeffler A, Pfeiffer DU, Lindsay JA, Soares Magalhães RJ, Lloyd DH.We investigated the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carriage in a convenience sample of purposely selected populations of dogs, cats and horses in the Greater London area. Swabs from carriage sites were pooled, enriched and processed by standard bacteriological methods. The presence of nuc and mecA was confirmed for MRSA. Risk factors were investigated among veterinary treatment group animals using exact logistic regression analysis. Twenty-six (1.53%) MRSA carriers were identified in the 1692 animals (15/704 dogs, 8/540 cats, 3/152 horses). Animals presenting ...
Nell B, Walde I.Diseases of the vitreous, fundus and optic nerve are described and illustrated according to their ophthalmological appearance. Vitreal alterations are commonly of developmental, degenerative, age related, traumatic or inflammatory origin and of minor clinical relevance. In contrast, those affecting the fundus, may be accompanied by visual deficits or blindness. Fundic lesions of inflammatory (multifocal or peripapillary chorioretinitis, haemorrhage, retinal detachment) and traumatic origin have to be differentiated from congenital (congenital stationary night blindness, colobomatous defects, r...
Atherton JG, Pitt TL.Pseudomonas aeruginosa isolates from equine clinical material were categorised according to their serotype and phage type. Epidemiological evidence showed that serotypes 02a, 03, 04, 06, 09 and 010 were the cause of genital and non-genital infections; somatic type 03 accounted for 50 per cent of isolates. The laboratory tests used were of no value in predicting whether or not a particular isolate was likely to be a venereal pathogen, but all the serotypes encountered had the potential to be pathogenic, given a favourable environment in which to multiply.
Alvarez I, Cipolini F, Wigdorovitz A, Trono K, Barrandeguy ME.The most used and reliable indicator of Equine infectious anemia virus (EIAV) infection is the detection of its specific antibodies in horse serum. In the present study, the performance of two commercial ELISA tests for the detection of EIAV antibodies as well as the potential advantages of their use as an EIAV infection screening tool were evaluated in 302 horse serum samples. Both ELISA assays showed 100% diagnostic sensitivity, and 92.3-94.3% diagnostic specificity. Discordant results were analyzed by immunoblot. The results showed that both ELISA tests are very efficient at detecting EIAV ...
Dutta SK, Shipley WD.Foals (farms 1 and 2) and mares (farms 1 and 3) vaccinated with a commercially available rhinopneumonitis vaccine were tested for the level of antibodies and for protection against the natural infection. The serum-neutralization (SN) antibody titers against equine herpesvirus type 1 were 1:8 or less in the majority of foals and 1:16 or higher in about 10%. The level of the nasal secretory antibody in the foals (farm 2) was less than 1:4. The vaccinated foals did not show any apparent respiratory tract infection for about 6 months and then an epizootic of respiratory tract disease appeared on f...
Vemulapalli R, Langohr IM, Sanchez A, Kiupel M, Bolin CA, Wu CC, Lin TL.Leptospirosis was identified to be the possible cause of premature birth in a foal on a farm with a history of repeated abortions. Using an appropriate polymerase chain reaction (PCR) assay, the presence of Leptospira kirschneri was detected in the tissues of the prematurely born foal. Further confirmation of L. kirschneri was obtained by nucleotide sequence analysis of the PCR-amplified DNA fragment and the partial 16S ribosomal RNA gene sequence. This report further supports mounting evidence that a PCR assay capable of detecting L. kirschneri should be included in routine diagnostic investi...
Liang FT, Granstrom DE, Zhao XM, Timoney JF.Sarcocystis neurona is the etiologic agent of equine protozoal myeloencephalitis (EPM). Based on an analysis of 25,000 equine serum and cerebrospinal fluid (CSF) samples, including samples from horses with neurologic signs typical of EPM or with histologically or parasitologically confirmed EPM, four major immunoblot band patterns have been identified. Twenty-three serum and CSF samples representing each of the four immunoblot patterns were selected from 220 samples from horses with neurologic signs resembling EPM and examined for inhibitory effects on the infectivity of S. neurona by an in vi...
Schneider RK, Bramlage LR, Mecklenburg LM, Moore RM, Gabel AA.Open drainage was used to treat 26 horses with persistent or severe septic arthritis/tenosynovitis. Infected synovial structures were drained through a small (3 cm) arthrotomy incision that was left open and protected by a sterile bandage. Joint lavage was performed in all 26 horses. In addition to systemic antibiotics, 23 of these horses were also treated with intra-articular antibiotics; amikacin (17 horses), gentamycin (2 horses), cefazolin (2 horses), and 2 horses were injected at different times with gentamycin and amikacin. The infection was eliminated from the involved synovial structur...
Tomczuk K, Kostro K, Grzybek M, Szczepaniak K, Studzińska M, Demkowska-Kutrzepa M, Roczeń-Karczmarz M.For this study, 724 gastrointestinal tracts of slaughter horses were investigated to determine the prevalence, intensity of Anoplocephala perfoliata and tapeworm development stages over the second, third and fourth quarter of 2012 and the first quarter of 2013. For each positive horse, faecal samples were collected from the rectum or small colon for coproscopic examinations. The samples were analysed using dedicated modified sedimentation-flotation methods. In total, 52 horses were infected with A. perfoliata in the course of the study, with an overall prevalence of 7.2 %. The prevalence chang...
Nielsen MK, Donoghue EM, Stephens ML, Stowe CJ, Donecker JM, Fenger CK.Parascaris spp. infections can lead to life-threatening small intestinal impactions in foals. Currently available diagnostic techniques cannot estimate the magnitude of an ascarid burden, and hence identify foals potentially at risk of developing impactions. Objective: To describe and evaluate an ultrasonographic transabdominal scoring technique for monitoring of ascarid burdens in foals and to perform a cost-benefit analysis of the application of this technique. Methods: A transabdominal ultrasonographic technique was validated against ascarid worm counts from 10 foals aged 162-294 days. In a...
Borel N, Grest P, Junge H, Wehrli Eser M.Vascular hamartomas are non-neoplastic developmental anomalies of vessels. Cases of cerebral vascular hamartomas have been previously reported in dogs and cats. A 4-week-old Freiberger foal had shown persistent problems with breathing and swallowing since birth, and bilateral laryngeal paralysis was diagnosed. The foal subsequently developed left sided facial nerve paralysis and a secondary corneal ulcer in the left eye. Necropsy revealed a pinkish mass in the obex region of the brain. The mass was further investigated by histology and immunohistochemistry. Histologically, the mass consisted o...
Martens JG, Martens RJ, Renshaw HW.The capacity of hematogenous polymorphonuclear neutrophilic leukocytes (PMNL) to kill Rhodococcus equi was compared in horses of various ages. A radioisotope bactericidal assay was used to determine the capacity of PMNL to kill R equi. Assays were conducted on PMNL from horses in 3 groups: group I, 13 foals with a mean age of 3.3 days; group II, 10 group-I foals at a mean age of 35.7 days; and group III, adult dams of group-I foals. Bacteria were obtained from the lungs of a foal with R equi pneumonia and opsonized with fresh adult equine serum that contained R equi specific antibody. The mean...
Fenton CS, Buckley TC.Rhodococcus equi is a gram positive, intracellular pathogen of foals worldwide. The aim of this study was to determine whether there was an increasing resistance occurring in Rhodococcus equi towards the antibiotics rifampin and erythromycin over a seven year period. The investigation was carried out with the use of E test strips (epsilometers) for rifampin and erythromycin in order to determine the Minimum Inhibitory Concentrations (MIC) values of Rhodococcus equi to these antibiotics. Results: The main results of this study found that the mean MICs were higher for erythromycin than for rifam...
Netherwood T, Binns M, Townsend H, Wood JL, Mumford JA, Chanter N.During a survey of foal diarrhoea between 1991 and 1994, Clostridium perfringens was significantly associated with disease with 56% of cases infected [1]. The contribution of enterotoxigenic C. perfringens to this association, was assessed by use of the reverse passive latex agglutination test for enterotoxin (RPLA; Oxoid Unipath) and vero cell toxicity neutralized by antitoxin on stored faecal samples and sporulated faecal isolates of C. perfringens. Polymerase chain reaction (PCR1) based on the DNA sequence for the whole enterotoxin gene [2] yielded a fragment from an equine isolate of the a...
Ayala-Valdovinos MA, Lemus-Flores C, Galindo-García J, Bañuelos-Pineda J, Rodríguez-Carpena JG, Sánchez-Chiprés D, Duifhuis-Rivera T.Theileria equi infection prevalence was calculated from 1000 blood samples obtained from apparently healthy horses in western Mexico. Samples were sent to the Animal Biotechnology Laboratory of the University of Guadalajara (Mexico) for T. equi diagnosis. Nested polymerase chain reaction (nPCR) was used as a diagnostic method to detect pathogen DNA. Using primers for the merozoite antigen-1 (EMA-1) gene, 19.70±2.47% of the horses (95% CI, 17.23-22.17%) tested positive for T. equi. There was no significant association between gender and T. equi infection. However, prevalence was higher among s...
Hasebe R, Kimura T, Nakamura K, Ochiai K, Okazaki K, Wada R, Umemura T.Equine herpesvirus 1 (EHV-1) shows endotheliotropism in the central nervous system (CNS) of infected horses. However, infection of endothelial cells has not been observed in the CNS of infected mice. To explore the basis for this difference in endotheliotropism, we compared the susceptibility of equine brain microvascular endothelial cells (EBMECs) and mouse brain microvascular endothelial cells (MBMECs) to EHV-1 infection. The kinetics of viral growth in EBMECs was typical of a fully productive infection whereas viral infection in MBMECs seemed to be nonproductive. Immunofluorescence microsco...
Khosravi AR, Nikaein D, Sharifzadeh A, Gharagozlou F.This study was carried out in order to isolate and identify the normal conjunctival fungal flora from Caspian miniature, Thoroughbred, Turkmen and Persian Arab breeds in Tehran, Iran. Methods: A total of seventy-two adult healthy horses were studied. Ocular samples were collected from right and left eyes by using sterile cotton swabs; samples were cultured on Sabouraud dextrose agar and incubated at 30°C for 7-10 days. Molds and yeasts were identified using macro and micro-morphological and physiological characteristics. Conclusions: Number of fungal colonies per eye varied between 0 and 123 ...
Malmgren L, Olsson Engvall E, Engvall A, Albihn A.This study was initiated in order to investigate the bacterial flora of the stallion genital tract by taking consecutive samples from normal stallions in regular use. The objective was to determine whether any growth of potential pathogens, particularly P. aeruginosa and K. pneumoniae, in fresh semen and urethra was associated with the presence of inflammatory cells in the semen and whether bacterial growth had any effect on sperm morphology and pregnancy results. Sixteen stallions, only used for A.I., housed at 3 different commercial stud farms, were used. A wide variety of microorganisms was...
Bannai H, Mae N, Ode H, Nemoto M, Tsujimura K, Yamanaka T, Kondo T, Matsumura T.Equine herpesvirus type 1 (EHV-1) is a major cause of winter pyrexia in racehorses in two training centers (Ritto and Miho) in Japan. Until the epizootic period of 2008-2009, a vaccination program using a killed EHV-1 vaccine targeted only susceptible 3-year-old horses with low antibody levels to EHV-1 antigens. However, because the protective effect was not satisfactory, in 2009-2010 the vaccination program was altered to target all 3-year-old horses. To evaluate the vaccine's efficacy, we investigated the number of horses with pyrexia due to EHV-1 or equine herpesvirus type 4 (EHV-4) infecti...
Franz M, Goodman LB, Van de Walle GR, Osterrieder N, Greenwood AD.A point mutation in the DNA polymerase gene in equine herpesvirus type 1 (EHV-1) is one determinant for the development of neurological disease in horses. Three recently conducted infection experiments using domestic horses and ponies failed to detect statistically significant differences in viral shedding between the neuropathogenic and non-neuropathogenic variants. These results were interpreted as suggesting the absence of a consistent selective advantage of the neuropathogenic variant and therefore appeared to be inconsistent with a systematic increase in the prevalence of neuropathogenic ...
Ziemer EL, Whitlock RH, Palmer JE, Spencer PA.The clinical and hematologic variables of 10 ponies with experimentally induced equine ehrlichial colitis (EEC; syn: Potomac horse fever) were studied for a 30-day period (6 ponies) or until death (4 ponies). The earliest clinical sign indicative of EEC was fever (rectal temperature exceeding 39 C). All ponies became depressed (CNS) at various times during the disease, and 90% of the ponies developed diarrhea between 9 and 15 days after infection was induced. The most significant hematologic change was an increase in plasma protein concentration after the onset of fever (P less than 0.05). The...
Palmer JE, Benson CE, Whitlock RH.Fourteen ponies and 3 horses were inoculated with Ehrlichia risticii 2 to 20 months after a similar initial inoculation. Although all 17 had clinical signs of equine ehrlichial colitis after the first inoculation, 16 of 17 remained clinically normal following the second inoculation. The remaining pony had a transient fever and developed signs of depression. Before the initial inoculation, none of the animals had a detectable antibody titer to E risticii. All animals developed titers after the initial infection; however, a significant change of titer did not develop after reinoculation in most ...
Venter GJ, Groenewald D, Venter E, Hermanides KG, Howell PG.Equine encephalosis virus (EEV) is widespread and prevalent in southern Africa. In this study, the oral susceptibility of Culicoides (Avaritia) imicola Kieffer (Diptera: Ceratopogonidae) to EEV was confirmed. In addition, C. (A.) bolitinos Meiswinkel, collected in the high-lying eastern Free State, South Africa, was systemically infected with the Bryanston serotype of EEV after feeding through a membrane on artificially infected equine blood containing 4.7 log10 PFU/mL of EEV. The mean infectivity of Bryanston virus in C. bolitinos increased from 1.2 log10 PFU/midge, in midges assayed for viru...
Gysens L, Vanmechelen B, Maes P, Martens A, Haspeslagh M.Infection with bovine papillomavirus (BPV) types 1 and 2 results in the most common skin tumor of horses, termed equine sarcoid. The persistent and recurrent nature of this tumor stands in contrast to the regressive nature of BPV-1/- 2 induced cutaneous papillomas in cattle. The circulation of horse-specific BPV-1/- 2 variants within equine populations has been suggested as a possible explanation for the difference in clinical presentation of BPV-1/- 2 infection between horses and cattle. In order to investigate this hypothesis, we identified 98 complete BPV-1/- 2 genomes using a Nanopore ...
Poppie MJ, McGuire TC.Combined immunodeficiency (CID), a defect in both B- and T-lymphocytes, was found to occur in 2.3% of 257 foals of Arabian breeding. All affected foals died by 5 months of age. The belief that CID is transmitted as an autosomal recessive genetic defect was supported by results from matings of dams and sires that had previously produced affected foals. Based on a prevalence of 2.3%, the proportion of carriers of the CID trait among the adult population surveyed was estimated to be 25.7%. Recent descriptions of other immunologic defects in foals emphasized the need for careful differential diagn...
Chirino-Trejo JM, Prescott JF.The antigens extracted from strains belonging to seven capsular serotypes of Rhodococcus equi, as well as from two wild strains isolated from pneumonic foals, were examined. Whole-cell antigens and soluble products present in broth culture supernatants were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, electroblotted onto nitrocellulose, and stained with serum from hyperimmunized rabbits or foals. Foal sera used included sera from pneumonic animals with known titer to equi factors; from animals bled monthly on a farm with enzootic pneumonia, and from animals bled mont...
Monzón CM, Mancebo OA, Roux JP.In a total of 165 blood samples from horses in the Province of Formosa (Argentina), the diagnosis for equine trypanosomiasis (T. evansi) was made using Giemsa-stained smears (GSS), wet blood films (WBF), Strout's concentration method (SCM), haematocrit centrifuge technique (HCT), buffy coat method (BCM) and mouse inoculation of blood (MBI). Trypanosoma evansi was demonstrated in 52 samples. Mouse inoculation gave a sensitivity of 88.2%; HCT 71.1%; BCM 63.4%; WBF 53.8%; SCM 46.1% and GSS 45.6%. No single method alone was totally effective. The haematocrit centrifuge technique, mouse inoculation...
Schnabel LV, Papich MG, Divers TJ, Altier C, Aprea MS, McCarrel TM, Fortier LA.Minocycline holds great potential for use in horses not only for its antimicrobial effects but also for its anti-inflammatory and neuroprotective properties. However, there are no pharmacokinetic or safety data available regarding the use of oral minocycline in horses. Objective: To determine pharmacokinetics, safety and penetration into plasma, synovial fluid, aqueous humour (AH) and cerebral spinal fluid (CSF) of minocycline after oral administration of multiple doses in horses and to determine the minimum inhibitory concentrations (MIC) of minocycline for equine pathogenic bacteria. Methods...
Beckers KF, Gomes VCL, Crissman KR, Liu CC, Schulz CJ, Childers GW, Sones JL.Placentitis is the leading cause of infectious abortion in the horse. Additionally, it can result in weak and/or growth restricted offspring. While the etiology of ascending placentitis is well described in mares, less is known regarding the pathogenesis of other types, such as nocardioform placentitis. This study aims to identify the microbial communities in different body sites of the pregnant mare in early gestation to establish a core microbiome that may be perturbed in pathologic pregnancies such as placentitis. We hypothesize that the equine placenta harbors a distinct resident microbiom...
Pellegrini A, Waiblinger S, Von Fellenberg R.Lysozyme from equine neutrophil granulocytes was isolated in a pure form by fast performance liquid chromatography, i.e. ion-exchange chromatography and reversed-phase chromatography. The lysozyme lysed Micrococcus luteus, Bacillus subtilis and Staphylococcus lentus and was also bactericidal against the Gram-negative bacteria Escherichia coli, Klebsiella pneumoniae, Bordetella bronchiseptica, and Serratia marcescens. Staphylococcus aureus and Staphylococcus epidermidis were not lysed. The lysozyme was only very slightly bactericidal for S. epidermidis and S. aureus. Equine neutrophil lysozyme ...
Donahue JM, Sells SF, Bolin DC.To identify Actinobacillus spp isolates recovered from fetuses and pericardial fluid from horses affected with mare reproductive loss syndrome (MRLS) and determine whether these bacterial species are the same as those isolated from clinically normal horses. Methods: Isolates of actinobacilli recovered from 18 horses with pericarditis and 109 fetuses aborted by mares affected by MRLS. Procedures-Actinobacillus spp isolates were identified to the level of species or subspecies by use of conventional phenotypic tests and biochemical and enzyme test kits. The 16S rRNA gene from selected isolates w...
Morris LH, Colgan S, Leathwick DM, Nielsen MK.Parasite control in foals is complicated by the concurrent presence of biologically diverse parasites with differing levels of anthelmintic resistance. Several combination anthelmintic products are available for use in horses, but information on their efficacies against important equine parasites is scarce. Two trials were performed in New Zealand during 2008 and 2011 on four different farms with substantially different anthelmintic treatment histories. The first trial evaluated the efficacy of an ivermectin/praziquantel/oxibendazole combination, a single active oxibendazole, and a single-acti...
