Salmonellosis in horses is an infectious disease caused by the bacterium Salmonella. This condition can lead to a range of clinical signs, from asymptomatic carriage to severe diarrhea and systemic illness. Horses can acquire Salmonella through contaminated feed, water, or contact with infected animals. The disease is of particular concern in equine facilities due to its potential for rapid spread and zoonotic risk. Diagnosis typically involves bacterial culture or polymerase chain reaction (PCR) testing of fecal samples. Management of salmonellosis includes isolation of affected animals, supportive care, and biosecurity measures to prevent transmission. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, pathogenesis, clinical presentation, and management strategies of salmonellosis in horses.
Zhang XX, Huang X, Li XQ, Wang ZY, Jiang Y, Jiao X, Li Q, Wang J, Zhong FG.Salmonella enterica serovar Kentucky ST198 has been increasingly reported in diverse sources worldwide, emerging as a globally epidemic clone. In this study, we aim to characterise the first isolated S. Kentucky ST198 strain from a horse in China. Methods: Twelve faecal samples were collected from horses at a farm in Shihezi, Xinjiang Province, China, and investigated for the presence of Salmonella. The minimum inhibitory concentrations of 15 antimicrobial agents were determined using the broth microdilution method. The whole genome of Sal140 was sequenced using the Illumina Hiseq platform and...
Pinn-Woodcock TL, Aprea MS, Lejeune M, Tomlinson JE.A common diagnostic approach for febrile horses is to test for a panel of potential pathogens. Panels are curated by expert opinion and vary between diagnostic laboratories. Objective: To report the results of a newly developed equine fever diagnostic panel (EFDP) between 2019 and 2023 and evaluate the frequency of positive results. Methods: Retrospective descriptive study. Methods: The EFDP requires submission of whole blood, nasal swab, and faecal samples, and includes PCR tests for 12 pathogens that can present as fever without localising signs of illness or infection. Submission metadata a...
McTernan SP, Heller J, Clulow JR, Gannon L, Huang R, Tidd N, Blishen A, Hughes KJ.Salmonella enterica subsp. enterica is responsible for substantial morbidity and mortality within horse populations, worldwide. The prevalence of Salmonella shedding in faeces has largely been reported in hospital settings, with limited information from general horse populations. Further, there is little understanding of the serotypes and antibiograms of Salmonella isolates from horses in Australia. The objectives of this study were to (1) estimate the prevalence of Salmonella in stud farm horse populations, (2) determine serotypes and antibiograms for isolates, and (3) determine whether seaso...
Kabir A, Kelley WG, Glover C, Erol E, Helmy YA.Salmonella is a foodborne pathogen that poses a significant threat to global public health. It affects several animal species, including horses. Salmonella infections in horses can be either asymptomatic or cause severe clinical illness. Infections caused by Salmonella are presently controlled with antibiotics. Due to the formation of biofilms and the emergence of antimicrobial resistance, the treatment has become more complicated. Our study focused on investigating the prevalence of Salmonella enterica in necropsied horses, assessing the capability for biofilm formation, and motility, determi...
Wilson CS, Carrick J, Shearer P, Heller J, Brookes VJ.Pregnancy failure is a serious economic and welfare concern in the Thoroughbred horse industry, yet its incidence and risk factors in Australia remain unclear. This retrospective, nested, case-control study investigated pregnancy failure in resident mares on studs in the Hunter Valley, Australia, in 2021-2022, in early (46-150 days), mid (151-270 days), and late (>270 days) gestation. We found an annual incidence risk of 5.4 pregnancy failure cases/100 45-day pregnancies (0.05 cases/mare; 95 % CI 0.04-0.07), with full-term (perinatal) losses (≥320 days) accounting for 24 % of cases (9...
Haywood LMB, Sheahan BJ.Equine colitis is a devastating disease with a high mortality rate. Infectious pathogens associated with colitis in the adult horse include Clostridioides difficile, Clostridium perfringens, Salmonella spp., Neorickettsia risticii/findlaynesis, and equine coronavirus. Antimicrobial-associated colitis can be associated with the presence of infectious pathogens. Colitis can also be due to non-infectious causes, including non-steroidal anti-inflammatory drug administration, sand ingestion, and infiltrative bowel disease. Current treatments focus on symptomatic treatment (restoring fluid and elect...
Amory H, Cesarini C, De Maré L, Loublier C, Moula N, Detilleux J, Saulmont M, Garigliany MM, Lecoq L.The objective of this retrospective study was to evaluate the clinical significance of fecal quantitative real-time polymerase chain reaction (qPCR) results when taking the cycle threshold values (Ct) into account. The study included 120 qPCR-positive fecal samples obtained from 88 hospitalized horses over a 2-year period. The mean Ct of the qPCR test was evaluated in regard to (1) clinical outcome and (2) systemic inflammatory response syndrome (SIRS) status (no SIRS, moderate SIRS, or severe SIRS) of the sampled horses. An ROC analysis was performed to establish the optimal cut-off Ct valu...
Bello K, Lorch G, Kim K, Toribio RE, Yan L, Xie Z, Hill K, Phelps M.Additional efficacious immunomodulatory treatment is needed for the management of immune-mediated disease in horses. Mycophenolate mofetil (MMF) is an immunosuppressive drug that warrants assessment as a viable therapeutic agent for horses. Objective: To evaluate the pharmacokinetics (PK) of multiple-day oral dosing of MMF in healthy horses and to determine the tolerability of this dosing regimen. Methods: Six healthy Standardbred mares. Methods: Horses received MMF 10 mg/kg PO q12h for 7 days in the fed state. Serial sampling was performed over 12 hours on Days 1 and 7 with trough sampl...
Pusterla N, Naranatt P, Swadia H, Winfield L, Hartwig A, Barnum S, Mendonsa E.The introduction of microfluidic card technology has opened the field for rapid point-of-care (POC) molecular assays, including fecal and environmental Salmonella spp. testing. The purpose of this study was to evaluate a novel POC PCR assay for the detection of Salmonella spp. in feces and environmental samples. A total of 143 fecal samples and 132 environmental samples were collected for POC PCR Salmonella spp. testing as well as qPCR testing. Each sample was inoculated into selenite broth and incubated for 18 to 24 hours. For the POC PCR assay, 14 μl of selenite broth were mixed with 126 μ...
Wang J, Guo K, Li S, Liu D, Chu X, Wang Y, Guo W, Du C, Wang X, Hu Z.Salmonella enterica subsp. serovar Abortusequi is a major pathogen in horse and donkey herds, causing abortion in pregnant equids and resulting in enormous economic losses. A rapid and reliable method is urgently needed to detect . Abortusequi in herds where the disease is suspected. To achieve this goal, a TaqMan-based real-time PCR assay targeting the gene for the flagellin protein phase 2 antigen FljB was developed. This real-time PCR assay had high specificity, sensitivity, and reproducibility. The detection limit of the assay was 30 copies/μL of standard plasmid and 10 CFU/μL of bacter...
Burgess BA.Managing Salmonella in equine populations can be challenging due to the epidemiology of this disease. In particular, due to the range of clinical outcomes, the occurrence of subclinical infections, and intermittent shedding. This greatly affects the ability to detect shedding and can lead to widespread environmental contamination and transmission. The veterinary profession can reduce the risk to stablemates and their caretakers, while meeting their ethical obligation, by appropriately managing these risks within animal populations and environments.
Kohnen AB, Wiedenheft AM, Traub-Dargatz JL, Short DM, Cook KL, Lantz K, Morningstar-Shaw B, Lawrence JP, House S, Marshall KL, Rao S.Several studies have investigated antimicrobial resistance (AMR) in Salmonella spp. and Escherichia coli isolated from hospitalized horses, but studies conducted on community-based populations of equids are limited. The factors associated with AMR in these bacteria in the general horse population are not well understood. The primary objective of our study was to estimate the prevalence of Salmonella and describe antimicrobial susceptibility of Salmonella and E. coli from equids across the United States. The second objective was to identify associations between health management and biosecurity...
Goni JI, Hendrix K, Kritchevsky J.It is important to determine if a horse is shedding Salmonella spp., but a complete culture series can be cost prohibitive. Objective: Determine the optimal pooling technique to maintain high sensitivity of Salmonella spp. culture using spiked samples, and then demonstrate the efficacy of this protocol on clinical submissions. Objective: Pooled fecal samples are as sensitive as 5 individual cultures for the detection of Salmonella shedding. Methods: A single Salmonella-negative horse from the university herd, and 19 hospitalized horses. Methods: Salmonella-free fecal samples were spiked with d...
Kilcoyne I, Magdesian KG, Guerra M, Dechant JE, Spier SJ, Kass PH.Gastrointestinal disease has been associated with shedding of Salmonella with previous studies demonstrating that horses with colic have a higher risk of acquiring and shedding Salmonella organisms. Objective: The purpose of this study was to determine the prevalence of and risk factors associated with Salmonella shedding in a colic population at a referral clinic. Methods: Retrospective case-control study. Methods: For each colic case that was positive for Salmonella (n = 56), two colic cases (n = 112) that tested negative for Salmonella, were enrolled as controls. Associations between va...
Mendonça FS, Navarro MA, Uzal FA.To determine if there were significant differences produced by 5 of the most prevalent causes of equine enterocolitis, we studied retrospectively the gross and microscopic pathology of 90 cases of enterocolitis submitted to the San Bernardino laboratory of the California Animal Health and Food Safety Laboratory. Included were cases caused by Clostridium perfringens type C (CP; n = 20), Clostridioides difficile (CD; n = 20), Paeniclostridium sordellii (PS; n = 15), Salmonella enterica subspecies enterica serovar Typhimurium (ST; n = 20), and NSAID intoxication (NS; n = 15). ...
Arnold CE, Pilla R, Chaffin MK, Leatherwood JL, Wickersham TA, Callaway TR, Lawhon SD, Lidbury JA, Steiner JM, Suchodolski JS.The fecal microbiome of healthy horses may be influenced by signalment, diet, environmental factors, and disease. Objective: To assess the effects of age, breed, sex, geographic location, season, diet, and colitis caused by antibiotic use (antimicrobial-associated diarrhea [AAD]) and Salmonella infection on fecal microbiota. Methods: Healthy horses (n = 80) were sampled from nonhospital environments across multiple geographical locations in the United States. Horses with AAD (n = 14) were defined as those that developed diarrhea secondary to antimicrobial use. Horses with Salmonella infect...
Harmer CJ.Conjugative plasmids are a major contributor to the global spread of antibiotic resistance determinants, but the tracking of their evolutionary history is often neglected. serovar Typhimurium ( Typhimurium) strain SRC27 was isolated from an equine infection in Australia in 1999. SRC27 was known to carry conjugative HI1 and I1 resistance plasmids. In this study, SRC27 was sequenced to determine the relationship between these HI1 and I1 resistance plasmids it was known to carry and HI1 and I1 resistance plasmids circulating worldwide. The resistance genes in the HI1 plasmid, pSRC27-H, are all l...
Rivera D, Allel K, Dueñas F, Tardone R, Soza P, Hamilton-West C, Moreno-Switt AI.Salmonella is a major bacterial foodborne pathogen that causes the majority of worldwide food-related outbreaks and hospitalizations. Salmonellosis outbreaks can be caused by multidrug-resistant (MDR) strains, emphasizing the importance of maintaining public health and safer food production. Nevertheless, the drivers of MDR Salmonella serovars have remained poorly understood. In this study, we compare the resistance profiles of Salmonella strains isolated from 4047 samples from domestic and wild animals in Chile. A total of 106 Salmonella strains (2.61%) are isolated, and their serogroups are ...
Bustos CP, Leiva CL, Gambarotta M, Guida N, Chacana PA.Equine salmonellosis is caused by several Salmonella serotypes, including Salmonella Newport, which cause enterocolitis and diarrhea. Treatment usually includes the administration of antibiotics. However, since multidrug-resistant Salmonella is commonly detected, alternative options to control the pathogen are needed. One of these options is the use of specific egg yolk antibodies (IgY) for passive immunotherapy. Thus, the aim of our work was to produce IgY antibodies against an equine S. Newport strain and assess their in vitro inhibitory activity. To this end, laying hens were immunized with...
Luethy D, Feldman R, Stefanovski D, Aitken MR.Acute colitis is a serious cause of morbidity and death in horses. Recent studies have compared clinical features of coronavirus and salmonellosis, but no study has compared clinical features of enteric salmonellosis, coronavirus, and neorickettsiosis. Objective: To identify risk factors for laminitis and nonsurvival to discharge in horses with enteric salmonellosis, coronavirus, or neorickettsiosis. Methods: Eighty-five horses hospitalized for acute colitis from 2011 to 2019. Methods: Retrospective case series. Medical record review (2011-2019) of adult (≥2 years) horses with colitis. Pri...
Ortolani F, Nannarone S, Sforna M, Gialletti R, Giglia G, Mandara MT.A 10-year-old Koninklijk Warmbloed Paardenstamboek Nederland (KWPN, Netherlands-based organization for registration of the Dutch Warmblood horses) mare was evaluated three times over four months because of recurrent colic. At every referral, a physical examination revealed a small colon impaction, which partially responded to food deprivation and oral administration of water and magnesium sulphate. Due to the recurrent nature of the small colon impaction, several differential diagnoses were considered: inflammatory bowel disease (IBD), chronic salmonellosis and myenteric ganglionopathies. At f...
Bustos CP, Dominguez JE, Garda D, Moroni M, Pallarols Molinari N, Herrera M, Chacana PA, Mesplet M.Salmonella spp. causes digestive clinical signs in horses. Foals and hospitalized animals are more susceptible to the disease. Nowadays, the report of multidrug-resistant Salmonella spp. producer of extended-spectrum β-lactamases, is more frequent. The aim of this work was to study the clonal relationship and antimicrobial susceptibility profiles among Salmonella ser. Typhimurium isolates, obtained during a salmonellosis outbreak in an Argentinian equine hospital. Thus, in 2017, we studied the genotypic profiles and the susceptibility to antimicrobials of the strains isolated from three anima...
Dor Z, Shnaiderman-Torban A, Kondratyeva K, Davidovich-Cohen M, Rokney A, Steinman A, Navon-Venezia S. is a major causative pathogen of human and animal gastroenteritis. Antibiotic resistant strains have emerged due to the production of extended-spectrum β-lactamases (ESBLs) posing a major health concern. With the increasing reports on ESBL-producing Enterobacterales that colonize companion animals, we aimed to investigate ESBL dissemination among ESBL-producing (ESBL-S) in hospitalized horses. We prospectively collected ESBL-S isolates from hospitalized horses in a Veterinary-Teaching Hospital during Dec 2015-Dec 2017. Selection criteria for ESBL-S were white colonies on CHROMagarESBL plate...
Neustroev MP, Petrova SG.An inactivated vaccine based on the BN-12 strain with the TNP-3 strain filtrate used as immunomodulator has been developed in order to prevent salmonella-induced equine abortion. Preclinical and clinical trials with the white mice and the horses, respectively, are carried out. The lack of toxicity is proven. The vaccine immunogenicity for mouse and mare models comprised 90 and 100%, respectively. The industrial vaccine tests showed that the industrial output of foals increased by 13.8% after immunization. Cost-effectiveness of the vaccine used with the TNP-3 strain filtrate comprised 14.1 r...
Pei L, Yang H, Qin S, Yan Z, Zhang H, Lan Y, Li A, Iqbal M, Shen Y.The objective of the present study was to evaluate the probiotic properties, security and antibacterial ability in vivo of isolated strains from healthy equine. In the present study, two Pediococcus acidilactici (P1 and P2) and two Lactobacillus equi (L1 and L2) were isolated. All isolates were died when exposed to pH 2.0 for 3 hours but survived at pH 3.0 and pH 4.0 with differential survival rate, and there is a higher survival rate at pH 4.0. Similarly, the isolates showed different tolerance to bile. The viable bacteria count was sustained at high levels in a tolerance test with artificia...
Wang X, Ji Y, Su J, Xue Y, Xi H, Wang Z, Bi L, Zhao R, Zhang H, Yang L, Guo Z, Guan Y, Feng X, Sun C, Lei L, Ur Rahman S, Dong J, Han W, Gu J. subsp. serovar Abortusequi is a frequently reported pathogen causing abortion in mares. In this study, the preventive and therapeutic effects of phage P SAE-01E2 against Abortusequi in a mouse model of abortion were investigated. Phage P SAE-01E2 was stable at different temperatures (4 to 70°C) and pH values (pH 4 to 10) and could lyse the majority of the serogroup O:4 and O:9 strains tested (25/28). There was no lysogeny-related, toxin, or antibiotic resistance-related gene in the genome of P SAE-01E2. All of these characteristics indicate that P SAE-01E2 has the potential for use in pha...
Soza-Ossandón P, Rivera D, Tardone R, Riquelme-Neira R, García P, Hamilton-West C, Adell AD, González-Rocha G, Moreno-Switt AI. is a highly infectious microorganism responsible for many outbreaks reported in equine hospitals. Outbreaks are characterized by high morbidity and mortality rates, nosocomial transmission to other patients, zoonotic transmission to hospital personnel, and even closure of facilities. In this study, 545 samples (environmental and hospitalized patients) were collected monthly during a 1-year period from human and animal contact surfaces in an equine hospital that received local and international horses. A total of 22 isolates were obtained from human contact surfaces (e.g., offices and pharmac...
Rothers KL, Hackett ES, Mason GL, Nelson BB.A 17-year-old Quarter Horse mare was evaluated for colic of 24-hour duration. Clinical signs and diagnostic evaluation were consistent with duodenitis-proximal jejunitis. The horse's clinical condition deteriorated despite medical treatment and was euthanized. Aerobic culture collected from small intestinal ingesta was positive for subsp. serovar Hadar. sp. is commonly implicated in nosocomial infections in equine veterinary hospitals usually through feces containing the organism. Considering sp. was cultured from the jejunal luminal contents and the large volume of nasogastric reflux that...
Hensel M, Meason-Smith C, Plumlee QD, Myers AN, Coleman MC, Lawhon S, Rodrigues Hoffmann A, Rech RR.Pulmonary mycosis secondary to enterocolitis is an uncommon diagnosis in equine medicine, but is thought to result from mucosal compromise and translocation of enteric fungi. The aetiological agent associated with translocation is often identified based on fungal culture or hyphal features in histological sections. In order to understand better the aetiological agents involved, six horses diagnosed with Salmonella enteritis and concurrent pulmonary mycosis were identified retrospectively through a database search of veterinary teaching hospital records. Samples from these cases were subjected ...
Burgess BA, Morley PS.Transmission of Salmonella in veterinary hospitals is typically associated with environmental contamination. Links between isolates recovered from hospitalized large animals and environment suggest animals as the likely source. Therefore, understanding factors influencing shedding is key in control. Shedding in hospitalized animals has been investigated, but many studies focused on subsets of animals limiting generalizability. Objective: (1) Investigate factors associated with fecal shedding of Salmonella among hospitalized large animals at a veterinary hospital. (2) Compare results obtained u...
Slovis NM, Elam J, Estrada M, Leutenegger CM.Diarrhoea caused by infectious agents is common in foals but there is no comprehensive molecular work-up of the relative prevalence of common agents and appearance of coinfections. Objective: To determine the prevalence of 9 infectious agents in gastrointestinal (GI)-diseased and healthy foals with ages ranging from 1 to 20 weeks of age and to what degree coinfections are associated with clinical signs of GI disease. Methods: Retrospective controlled observational study. Methods: The population consisted of 88 Thoroughbred foals aged 2 days to 17 weeks born on 32 different studfarms in Kentuck...
Langan RC, Gotsch PB, Krafczyk MA, Skillinge DD.Ulcerative colitis is a chronic disease with recurrent symptoms and significant morbidity. The precise etiology is still unknown. As many as 25 percent of patients with ulcerative colitis have extraintestinal manifestations. The diagnosis is made endoscopically. Tests such as perinuclear antineutrophilic cytoplasmic antibodies and anti-Saccharomyces cerevisiae antibodies are promising, but not yet recommended for routine use. Treatment is based on the extent and severity of the disease. Rectal therapy with 5-aminosalicylic acid compounds is used for proctitis. More extensive disease requires t...
Frederick J, Giguère S, Sanchez LC.Diarrhea is common in foals but there are no studies investigating the relative prevalence of common infectious agents in a population of hospitalized diarrheic foals. Objective: To determine the frequency of detection of infectious agents in a population of hospitalized foals with diarrhea and to determine if detection of specific pathogens is associated with age, outcome, or clinicopathologic data. Methods: Two hundred and thirty-three foals < or = 10 months of age with diarrhea examined at a referral institution. Methods: Retrospective case series. Each foal was examined for Salmonella s...
Myers LL, Shoop DS, Byars TD.Enterotoxigenic Bacteroides fragilis (ETBF) was isolated from the feces of 10 of 40 Thoroughbred foals with naturally acquired diarrhea. Of the 10 foals positive for ETBF, 6 were less than or equal to 7 days old. Fecal specimens from 4 of the 10 foals also were positive for rotavirus, and one fecal specimen was positive for Salmonella enteritidis. Clinical or hematologic differences were not evident between foals infected with ETBF only and those infected with ETBF and another recognized enteric pathogen. Only 1 of 10 foals infected with ETBF died. Of 25 adult rabbits with ligated ceca, 23 dev...
Harlow BE, Lawrence LM, Flythe MD.Antibiotics are important to equine medicine, but antibiotic-associated diarrhea (AAD) can lead to poor performance and even mortality. AAD is attributed to disruption of the hindgut microbiota, which permits proliferation of pathogenic microbes. The goal of this study was to evaluate the effects of common antibiotics on cellulolytic bacteria, lactobacilli, and AAD-associated pathogens in the feces of healthy horses. Fifteen horses were assigned to three treatment groups (blocked by age and sex): control (no antibiotics), trimethoprim-sulfadiazine (PO), or ceftiofur (IM). Fecal samples (n=8 pe...
Frye JG, Fedorka-Cray PJ.Third-generation cephalosporin (3GC) antimicrobials are the drugs of choice for treatment of salmonellosis in children. Salmonella isolated in the USA are assayed by the National Antimicrobial Resistance Monitoring System (NARMS) for resistance to antimicrobials including first-, second- and third-generation cephalosporins. From 1999 to 2003, 34,411 Salmonella were isolated from animals in the USA, of which 10.9% were found to be resistant to ceftiofur, a 3GC used in animals, whilst only 0.3% were resistant to ceftriaxone, a 3GC used in human medicine. Ceftiofur resistance rose from 4.0% in 19...
Zhao S, McDermott PF, White DG, Qaiyumi S, Friedman SL, Abbott JW, Glenn A, Ayers SL, Post KW, Fales WH, Wilson RB, Reggiardo C, Walker RD.Three hundred and eighty Salmonella isolates recovered from animal diagnostic samples obtained from four state veterinary diagnostic laboratories (AZ, NC, MO, and TN) between 2002 and 2003 were tested for antimicrobial susceptibilities and further characterized for bla(CMY) beta-lactamase genes, class 1 integrons and genetic relatedness using PFGE. Forty-seven serovars were identified, the most common being S. Typhimurium (26%), S. Heidelberg (9%), S, Dublin (8%), S. Newport (8%), S. Derby (7%), and S. Choleraesuis (7%). Three hundred and thirteen (82%) isolates were resistant to at least one ...
Salmonella enterica subsp. enterica serovar Abortusequi is frequently reported as a cause of abortion in mares and neonatal septicemia and polyarthritis in Asian and African countries, but only sporadically in Europe and the United States. We report an outbreak of S. Abortusequi in foals in Italy, characterized by high mortality. In a herd of Murgese horses, 10 of 34 newborns died at birth and a further 7 died, after developing severe clinical signs, during the first 10 d of life. Tissue specimens from different organs of 2 dead foals, synovial fluids from 4 sick foals, and vaginal and rectal ...
Dallap Schaer BL, Aceto H, Rankin SC.Nosocomial salmonellosis is an important problem for large animal veterinary teaching hospitals (VTHs). Objective: To describe failure of an Infection Control Program (ICP) that resulted in an outbreak of salmonellosis caused by Salmonella Newport multidrug resistant (MDR)-AmpC at a large animal VTH. Methods: Sixty-one animals identified with the outbreak strain of Salmonella. Methods: Retrospective study: Data collected included signalment, presenting complaint, duration of hospitalization, discharge status, and financial information. Phenotypic and genotypic characterization was performed on...
Barr BS, Waldridge BM, Morresey PR, Reed SM, Clark C, Belgrave R, Donecker JM, Weigel DJ.Although antimicrobial-associated diarrhoea (AAD) is the most frequently observed adverse effect of antimicrobial therapy in horses, few multicentred studies on the prevalence of AAD have been performed. Objective: To determine the prevalence of AAD in horses that developed diarrhoea after antimicrobial treatment for nondiarrhoeic conditions and identify the antimicrobials used. Methods: The 2009 database of 3 referral hospitals was searched to identify nonhospitalised horses (weanling age or older) treated with antimicrobials for nongastrointestinal conditions. Horses with these criteria that...
Pirie RS, Dixon PM, Collie DD, McGorum BC.To investigate whether inhaled endotoxin contributes to airway inflammation and dysfunction in stabled horses, control (n = 6) and asymptomatic heaves (previously termed chronic obstructive pulmonary disease)-susceptible (n = 7) horses were given inhalation challenges with 20, 200 and 2,000 microg of soluble Salmonella typhimurium Ra60 lipopolysaccharide (LPS). LPS inhalation induced a dose-dependent neutrophilic airway inflammatory response in both groups. Inhalation with 2,000 microg of LPS also induced detectable lung dysfunction in the heaves group. LPS inhalation did not alter clinical sc...
Leon IM, Lawhon SD, Norman KN, Threadgill DS, Ohta N, Vinasco J, Scott HM.Although Salmonella enterica can produce life-threatening colitis in horses, certain serotypes are more commonly associated with clinical disease. Our aim was to evaluate the proportional morbidity attributed to different serotypes, as well as the phenotypic and genotypic antimicrobial resistance (AMR) of Salmonella isolates from patients at an equine referral hospital in the southern United States. A total of 255 Salmonella isolates was obtained from clinical samples of patients admitted to the hospital between 2007 and 2015. Phenotypic resistance to 14 antibiotics surveilled by the U.S. Nati...
Kurowski PB, Traub-Dargatz JL, Morley PS, Gentry-Weeks CR.To use real-time polymerase chain reaction (PCR) technology to develop a highly sensitive and specific diagnostic assay for the detection of Salmonella spp in fecal specimens. Methods: 299 fecal specimens from cattle, horses, and dogs. Methods: Enrichment of fecal specimens was followed by genomic DNA extraction by use of commercially available isolation kits. Real-time PCR assay was performed to target a Salmonella spp-specific DNA segment. Results of real-time PCR assay were compared with bacterial culture results to determine relative sensitivity and specificity. Results: Use of the spaQ pr...
Madewell BR, Tang YJ, Jang S, Madigan JE, Hirsh DC, Gumerlock PH, Silva J.Intestinal colonization with toxigenic strains of Clostridium difficile was documented in 9 of 10 horses with acute onset diarrhea in a veterinary medical teaching hospital, whereas a similar isolate was detected in only 1 of 23 other horses without diarrhea in the hospital. One horse with diarrhea was infected simultaneously with both C. difficile and Salmonella krefeld. Clostridium difficile was detected by fecal culture on selective medium, confirmed with a latex particle agglutination test, and identified as toxigenic by polymerase chain reaction amplification of toxin A and toxin B gene s...
Arnold CE, Pilla R, Chaffin MK, Leatherwood JL, Wickersham TA, Callaway TR, Lawhon SD, Lidbury JA, Steiner JM, Suchodolski JS.The fecal microbiome of healthy horses may be influenced by signalment, diet, environmental factors, and disease. Objective: To assess the effects of age, breed, sex, geographic location, season, diet, and colitis caused by antibiotic use (antimicrobial-associated diarrhea [AAD]) and Salmonella infection on fecal microbiota. Methods: Healthy horses (n = 80) were sampled from nonhospital environments across multiple geographical locations in the United States. Horses with AAD (n = 14) were defined as those that developed diarrhea secondary to antimicrobial use. Horses with Salmonella infect...
Shaw SD, Stämpfli H.Acute, infectious, diarrhea in adult horses is a major cause of morbidity and is associated with numerous complications. Common causes include salmonellosis, clostridiosis, Coronavirus, and infection with Neorickettsia risticii (Potomac horse fever). Treatment is empirical and supportive until results of specific diagnostic tests are available. Supportive care is aimed at restoring hydration, correcting electrolyte imbalances, and limiting the systemic inflammatory response. The mainstays of therapy are intravenous fluid therapy, electrolyte supplementation where necessary, nonsteroidal anti-i...
Soza-Ossandón P, Rivera D, Tardone R, Riquelme-Neira R, García P, Hamilton-West C, Adell AD, González-Rocha G, Moreno-Switt AI. is a highly infectious microorganism responsible for many outbreaks reported in equine hospitals. Outbreaks are characterized by high morbidity and mortality rates, nosocomial transmission to other patients, zoonotic transmission to hospital personnel, and even closure of facilities. In this study, 545 samples (environmental and hospitalized patients) were collected monthly during a 1-year period from human and animal contact surfaces in an equine hospital that received local and international horses. A total of 22 isolates were obtained from human contact surfaces (e.g., offices and pharmac...
Cohen ND, Martin LJ, Simpson RB, Wallis DE, Neibergs HL.To compare the sensitivity of polymerase chain reaction (PCR) with microbiological culture for detecting salmonellae in equine fecal samples and equine environmental swab specimens. Methods: Samples and specimens were tested by PCR and microbiological culture. Methods: A fecal sample from each of 152 horses admitted consecutively to the clinic for evaluation by the outpatient service, 282 fecal samples from 110 hospitalized horses that had been submitted to the clinical microbiology laboratory, and 313 environmental swab specimens were examined. Methods: Each sample and specimen in the study w...
Ernst NS, Hernandez JA, MacKay RJ, Brown MP, Gaskin JM, Nguyen AD, Giguere S, Colahan PT, Troedsson MR, Haines GR, Addison IR, Miller BJ.To estimate prevalence of and identify risk factors for fecal Salmonella shedding among hospitalized horses with signs of gastrointestinal tract disease. Methods: Cross-sectional study. Methods: 465 hospitalized horses with gastrointestinal tract disease. Methods: Horses were classified as positive or negative for fecal Salmonella shedding during hospitalization by means of standard aerobic bacteriologic methods. The relationship between investigated exposure factors and fecal Salmonella shedding was examined by means of logistic regression. Results: The overall prevalence of fecal Salmonella ...
Vo AT, van Duijkeren E, Fluit AC, Gaastra W.To investigate the genotypic resistance of integron-carrying Salmonella Typhimurium isolates from horses and their genetic relationship. Methods: Sixty-one Salmonella isolates were screened for the presence of class 1 integrons by PCR. The gene cassettes of integron-positive isolates were detected by PCR, restriction fragment length polymorphism typing, and sequencing. The potential for the transfer of resistance determinants was investigated by conjugation experiments. The presence of Salmonella genomic island 1 (SGI1) or its variants was studied by PCR and nucleotide sequencing. PFGE was use...
Tillotson K, Savage CJ, Salman MD, Gentry-Weeks CR, Rice D, Fedorka-Cray PJ, Hendrickson DA, Jones RL, Nelson W, Traub-Dargatz JL.During the past 11 years, there have been numerous reports of outbreaks of salmonellosis involving horses in veterinary teaching hospitals. Some of these outbreaks have been associated with Salmonella serotypes not commonly associated with infection of horses. Salmonella infantis is among the more common Salmonella serotypes isolated from human beings, and is an important pathogen in the broiler chicken industry. However, it was not commonly isolated from horses or cattle on a national basis between 1993 and 1995. In this report, we describe an outbreak of S infantis infection among large anim...
Wang X, Ji Y, Su J, Xue Y, Xi H, Wang Z, Bi L, Zhao R, Zhang H, Yang L, Guo Z, Guan Y, Feng X, Sun C, Lei L, Ur Rahman S, Dong J, Han W, Gu J. subsp. serovar Abortusequi is a frequently reported pathogen causing abortion in mares. In this study, the preventive and therapeutic effects of phage P SAE-01E2 against Abortusequi in a mouse model of abortion were investigated. Phage P SAE-01E2 was stable at different temperatures (4 to 70°C) and pH values (pH 4 to 10) and could lyse the majority of the serogroup O:4 and O:9 strains tested (25/28). There was no lysogeny-related, toxin, or antibiotic resistance-related gene in the genome of P SAE-01E2. All of these characteristics indicate that P SAE-01E2 has the potential for use in pha...
Schott HC, Ewart SL, Walker RD, Dwyer RM, Dietrich S, Eberhart SW, Kusey J, Stick JA, Derksen FJ.Between May 1996 and February 1997, 27 horses and a veterinary student at a veterinary teaching hospital developed apparent nosocomial Salmonella Typhimurium infection. The source of the multiple-drug resistant Salmonella Typhimurium was a neonatal foal admitted for treatment of septicemia. A high infection rate (approx 13% of hospitalized horses) coupled with a high case fatality rate (44%) for the initial 18 horses affected led to a decision to close the hospital for extensive cleaning and disinfection. Despite this effort and modification of hospital policies for infection control, 9 additi...
Traub-Dargatz JL, Salman MD, Jones RL.A study was designed to identify epidemiologic factors associated with the development and spread of salmonellae in horses in a veterinary teaching hospital, through a case-control study and a longitudinal follow-up prospective study. In the case-control study, 44 horses shedding salmonellae in feces were compared with 99 control horses not shedding salmonellae in feces; regarding breed, sex, age and initial diagnosis, none of the odds ratios for study factors was significant. The factors found to be associated with fecal shedding of salmonellae in the prospective study included diarrhea at th...
van Duijkeren E, Wannet WJ, Heck ME, van Pelt W, Sloet van Oldruitenborgh-Oosterbaan MM, Smit JA, Houwers DJ.We studied 232 Salmonella strains from horses with salmonellosis in The Netherlands, isolated in the period from 1993 to 2000 in order to provide insight in the dynamics of sero-, phage types (pt) and antibiotic susceptibilities over time. The strains were tested for susceptibility to seven antimicrobial agents using the agar diffusion method. In addition, the isolates were sero typed and Salmonella enterica subspecies enterica Typhimurium and Enteritidis strains were further phage typed. S. Typhimurium strains of phage type 506 and 401 (both classified as DT 104 in the English phage typing sy...
Zoonoses and public healthSeptember 28, 2011
Volume 59, Issue 3 217-228 doi: 10.1111/j.1863-2378.2011.01438.x
Bolton DJ, O'Neill CJ, Fanning S.The aims of this study were to investigate the incidence of Salmonella, verocytotoxigenic Escherichia coli (VTEC)/Escherichia coli O157 and Campylobacter on four mixed farms and to characterize the isolates in terms of a range of virulence factors. Eighty-nine composite (five different samples from the same animal species combined) faecal [cattle (24), pigs (14), sheep (4), poultry (4), horses (7), deer (4), dogs (9), rodents (2) and wild birds (20)] samples, 16 composite soil samples plus 35 individual water samples were screened using culture-based, immunomagnetic separation and molecular me...
Luethy D, Feldman R, Stefanovski D, Aitken MR.Acute colitis is a serious cause of morbidity and death in horses. Recent studies have compared clinical features of coronavirus and salmonellosis, but no study has compared clinical features of enteric salmonellosis, coronavirus, and neorickettsiosis. Objective: To identify risk factors for laminitis and nonsurvival to discharge in horses with enteric salmonellosis, coronavirus, or neorickettsiosis. Methods: Eighty-five horses hospitalized for acute colitis from 2011 to 2019. Methods: Retrospective case series. Medical record review (2011-2019) of adult (≥2 years) horses with colitis. Pri...
Ekiri AB, MacKay RJ, Gaskin JM, Freeman DE, House AM, Giguère S, Troedsson MR, Schuman CD, von Chamier MM, Henry KM, Hernandez JA.To examine the relationship between abdominal surgery and nosocomial Salmonella infections and the relationship between high caseload in combination with abdominal surgery and nosocomial Salmonella infections in hospitalized horses with signs of gastrointestinal tract disease. Methods: 140 horses. Methods: Case-control study. Methods: To accomplish the first objective, 1 to 4 control horses were matched with each nosocomial case horse on the basis of admission date of a primary case horse. The frequency of abdominal surgery and other investigated exposure factors were compared between nosocomi...
Smith BP, Reina-Guerra M, Hardy AJ.Feces from 1,451 horses entering a veterinary hospital over a 13-month period were cultured for salmonella. A total of 46 horses (3.2%) yielded 1 or more salmonella-positive fecal cultures. Twenty horses were found to be excreting salmonella in the feces on admission, and 5 of these later had severe diarrhea associated with enteric salmonellosis. Abdominal surgery and other severe stresses were associated with all cases of severe enteric salmonellosis. Serotypes of salmonella isolated included Salmonella agona (15), S anatum (14), S typhimurium (7), S typhimurium var copenhagen (4), S infantis...
