Pneumonia in horses is a respiratory condition characterized by inflammation of the lungs, often caused by bacterial, viral, or fungal infections. It can affect horses of all ages, though young and immunocompromised animals are more susceptible. Clinical signs of pneumonia in horses may include coughing, nasal discharge, fever, and labored breathing. Diagnosis typically involves a combination of clinical examination, imaging techniques such as radiography or ultrasonography, and laboratory tests including blood work and microbial cultures. Treatment strategies vary depending on the underlying cause and may involve antimicrobial therapy, supportive care, and environmental management. This page compiles peer-reviewed research studies and scholarly articles that explore the etiology, pathophysiology, diagnosis, and treatment of pneumonia in equine populations.
Muscatello G, Gilkerson JR, Browning GF.Virulent Rhodococcus equi causes pyogranulomatous bronchopneumonia in foals. The route of infection of foals has been considered to be inhalation of aerosolized bacteria from soil that is contaminated with equine feces. Thus, disease caused by R. equi has been regarded as an opportunistic infection of environmental origin and not a contagious disease. In this study, we report the exhalation of virulent R. equi from the respiratory tract of naturally infected foals. A handheld air-monitoring system was used to recover virulent R. equi from the exhaled breath of foals, and the concentration of v...
Flaminio MJ, Nydam DV, Marquis H, Matychak MB, Giguère S.Susceptibility of foals to Rhodococcus equi pneumonia is exclusive to the first few months of life. The objective of this study was to investigate the immediate immunologic response of foal and adult horse antigen-presenting cells (APCs) upon infection with R. equi. We measured the activation of the antigen-presenting major histocompatibility complex (MHC) class II molecule, costimulatory molecules CD40 and CD86, the cytokine interleukin-12 (IL-12), and the transcriptional factor interferon regulatory factor 1 (IRF-1) in monocyte-derived macrophages (mMOs) and dendritic cells (mDCs) of adult h...
Nerren JR, Payne S, Halbert ND, Martens RJ, Cohen ND.Rhodococcus equi is an intracellular pathogen of macrophages that causes rhodococcal pneumonia in foals and immunocompromised people. Evidence exists that neutrophils play a vital role in resistance to infection with R. equi; however, the means by which neutrophils exert their effects have not been clearly defined. In addition to directly killing bacteria, neutrophils also may exert a protective effect by linking innate and adaptive immune responses. In the present study we evaluated the cytokine expression profiles of adult equine neutrophils in response to stimulation with isogenic strains o...
Nerren JR, Martens RJ, Payne S, Murrell J, Butler JL, Cohen ND.Although evidence exists that neutrophils play a vital role in resistance to infection with Rhodococcus equi, the means by which neutrophils exert their effects have not been clearly defined. In the present study we evaluated differences in cytokine expression by unstimulated and R. equi-stimulated neutrophils obtained from newborn foals and subsequently at 2-, 4-, and 8-weeks of age. Stimulation with virulent R. equi induced significantly (P<0.05) greater expression of IFNgamma, TNFalpha, IL-6, IL-8, IL-12p40, IL-12p35, and IL-23p19 mRNA relative to expression by unstimulated neutrophils, ...
DebRoy C, Roberts E, Jayarao BM, Brooks JW.Extraintestinal pathogenic Escherichia coli (ExPEC) strains carrying distinct virulence attributes are known to cause diseases in humans and animals and infect organs other than the gastrointestinal tract. A fatal case of bronchopneumonia in a 12-year-old female Quarterhorse was investigated. Following postmortem examination, E. coli, Enterococcus sp., and Klebsiella pneumonia were isolated from the lungs, which contained multifocal intra-alveolar accumulations of neutrophils and macrophages with edema, hemorrhage, and fibrin. The strain of E. coli belonged to O2H21 and carried virulence genes...
Szeredi L, Jánosi S, Tenk M.Klebsiella (K.) oxytoca infection induced the abortion of a female equine fetus in the 10th month of pregnancy. Bacteria were cultured from the liver, lung and stomach content. They were labelled with an anti-Mycobacterium bovis antibody in the thymus, liver and lungs and were stained with Giemsa and Brown-Brenn staining in the thymus and lung. The diffusely consolidated lungs contained numerous grey-whitish foci 2-4 mm in diameter, which corresponded to severe pyogranulomatous pneumonia characterised by numerous intraalveolar neutrophils and macrophages and multinucleated Langhans' giant cell...
Stokol T, Gold J, Johnson A, Ainsworth D.A 3-day-old filly was presented to the Cornell University Hospital for Animals with an umbilical hematoma and mild aspiration pneumonia. The foal underwent abdominal surgery for resection of the hematoma. Recovery was uneventful, but 3 days after surgery, the foal became progressively tachypneic. Imaging studies revealed bilateral pleural effusion and pleuropneumonia. Cytologic evaluation and bacterial culture of the pleural fluid from both sides of the chest revealed sterile exudates, consisting mostly of neutrophils, with fewer macrophages and lymphocytes. Pleural fluid macrophages contained...
Bell SA, Drew CP, Wilson WD, Pusterla N.Idiopathic chronic eosinophilic pneumonia of horses is incompletely described. Objective: To describe the physical examination, clinicopathologic, histopathologic, and radiographic features and response to corticosteroid treatment of idiopathic chronic eosinophilic pneumonia of horses. Methods: Seven horses with eosinophilic pneumonia. Methods: Retrospective, descriptive study. Results: Anamnesis, clinical signs, and clinicopathologic and radiologic findings in 7 adult horses with histologically confirmed eosinophilic pneumonia were reviewed. The horses were examined for signs of chronic respi...
Sebastian MM, Giles RC, Donahu JM, Sells SF, Fallon L, Vickers ML.Placentitis, funisitis and fetal bronchopneumonia were diagnosed in an aborted full-term Thoroughbred fetus and its placenta by histopathological examination. Dermatophilus congolensis organisms were isolated from placenta, lung and stomach content. The genotypic identification of aerobic culture was confirmed by sequential analysis of the entire 16S rDNA gene. This is the first report of Dermatophilus congolensis-associated abortion in any species.
Chaffin MK, Cohen ND, Martens RJ.To determine the effect of azithromycin chemoprophylaxis on the cumulative incidence of pneumonia caused by Rhodococcus equi, age at onset of pneumonia, and minimum inhibitory concentration (MIC) of azithromycin for R equi isolates cultured from fecal and clinical samples. Methods: Controlled, randomized clinical trial. Methods: 338 foals born and raised at 10 equine breeding farms; each farm had a history of endemic R equi infections. Methods: Group 1 foals were control foals, and group 2 foals were treated with azithromycin (10 mg/kg [4.5 mg/lb], PO, q 48 h) during the first 2 weeks after bi...
Phumoonna T, Barton MD, Vanniasinkam T, Heuzenroeder MW.Rhodococcus equi remains a significant bacterial pathogen, causing severe pyogranulomatous pneumonia in foals aged 1-3 months. There is no effective vaccine currently available for the prevention of R. equi pneumonia. DNA vaccines are known to offer specific advantages over conventional vaccines. The aim of this study was to demonstrate efficacy of our recombinant DNA vaccine candidates, namely pcDNA3-Re1, pcDNA3-Re3 and pcDNA3-Re5 by combining a heat shock protein GroEL2 to a virulence-associated protein A (VapA) from R. equi to protect C3H/He mice against the R. equi infection. VapA was show...
Patterson-Kane JC, Carrick JB, Axon JE, Wilkie I, Begg AP.The first outbreak of equine influenza virus (EIV) infection was confirmed in Australia in 2007. Some EIV-positive young foals died with bronchointerstitial pneumonia, an rare disease process in this age group that is often postulated to be caused by viral infection. Objective: The aim of this study was to describe post mortem lesions in EIV-infected foals. Methods: Post mortem examinations were conducted on 11 young foals (age 2-12 days) submitted to the Scone Veterinary Hospital, NSW over a 2-month period in 2007. The foals had presented with or developed fatal pneumonia, and were known or s...
Cohen ND, Carter CN, Scott HM, Chaffin MK, Smith JL, Grimm MB, Kuskie KR, Takai S, Martens RJ.To determine whether soil concentrations of total or virulent Rhodococcus equi differed among breeding farms with and without foals with pneumonia caused by R equi. Methods: 37 farms in central Kentucky. Procedures-During January, March, and July 2006, the total concentration of R equi and concentration of virulent R equi were determined by use of quantitative bacteriologic culture and a colony immunoblot technique, respectively, in soil specimens obtained from farms. Differences in concentrations and proportion of virulent isolates within and among time points were compared among farms. Resul...
Pusterla N, Jones ME, Mohr FC, Higgins JK, Mapes S, Jang SS, Samitz EM, Byrne BA.A case of fatal pulmonary hemorrhage in a 6-year-old American Paint mare with a 2-week history of intermittent coughing, fever, and epistaxis is described. Significant macroscopic abnormalities at postmortem examination were restricted to the respiratory system, and microscopically, severe pulmonary hemorrhage with suppurative bronchopneumonia was found. Actinobacillus equuli subsp. haemolyticus was cultured from a transtracheal wash performed antemortem as well as from the lungs at necropsy. The presence of airway-associated hemorrhage in conjunction with bacterial bronchopneumonia suggested ...
Venner M, Reinhold B, Beyerbach M, Feige K.The prophylactic application of azithromycin to prevent pulmonary abscesses in foals was evaluated on a stud with endemic Rhodococcus equi pneumonia. Forty-five foals served as untreated controls in two groups. Twenty-five foals were given azithromycin (10mg/kg) orally once daily for 4 weeks. The foals were examined once a week from birth to the age of 5 months. If clinical signs or leucocytosis were noted and pulmonary sonographic findings (diameter >10 mm) were observed, the diagnosis of abscessing pneumonia was made. The prevalence of pulmonary abscesses was similar in the control groups (3...
Lopez AM, Townsend HG, Allen AL, Hondalus MK.Rhodococcus equi causes serious pneumonia in neonatal foals and is an opportunistic pathogen of people with compromised cellular immunity. No effective vaccine against R. equi disease in foals is available. We tested the safety and immunogenicity of a live, fully attenuated riboflavin auxotrophic candidate vaccine strain of R. equi (R. equi rib-). We demonstrated that R. equi rib- is immunogenic and capable of inducing IFN-gamma responses in immunocompetent BALB/c mice, yet it is safe even in an immunocompromised SCID mouse infection model. Moreover, it protects immunocompetent mice against vi...
Muscatello G, Leadon DP, Klayt M, Ocampo-Sosa A, Lewis DA, Fogarty U, Buckley T, Gilkerson JR, Meijer WG, Vazquez-Boland JA.Infection with Rhodococcus (Corynebacterium) equi is a well-recognised condition in foals that represents a consistent and serious risk worldwide. The condition manifests itself primarily as one of pulmonary abscessation and bronchitis, hence the terminology of 'rattles' derived from its most obvious clinical sign, frequently terminal when first identified. This review addresses the clinical manifestation, bacteriology and pathogenesis of the condition together with recent developments providing knowledge of the organism in terms of virulence, epidemiology, transmission and immune responses. E...
Hobo S, Niwa H, Anzai T.In the present study, the concentrations of serum amyloid A and surfactant protein D in sera were measured to evaluate them for identification of the clinical condition of horses with bacterial pneumonia. The study utilized 185 clinically healthy control thoroughbreds and 9 thoroughbreds for experimental infectious study with S. zooepidemicus. Blood samples were collected from the 185 healthy control thoroughbreds. The 9 thoroughbreds were experimentally infected S. zooepidemicus using an endoscopic injection to a lung lobe and were then observed of clinical conditions. Blood samples were coll...
Pei Y, Nicholson V, Woods K, Prescott JF.Rhodococcus equi causes fatal granulomatous pneumonia in foals and immunocompromised animals and humans. However, there is no effective vaccine against this infection. In this study, the chromosomal genes isocitrate lyase (icl) and cholesterol oxidase (choE) were chosen as targets for mutation and assessment of the double mutant as an intrabronchial vaccine in 1-week-old foals. Using a modification of a suicide plasmid previously developed in this laboratory, we developed a choE-icl unmarked deletion mutant of R. equi strain 103+. Five 1-week-old foals were infected intrabronchially with the m...
Witte W, Strommenger B, Stanek C, Cuny C.Methicillin-resistant Staphylococcus aureus of clonal lineage ST398 that exhibits related spa types and contains SCCmec elements of types IVa or V has been isolated from colonized and infected humans and companion animals (e.g., dog, pig, horse) in Germany and Austria. Of particular concern is the association of these cases with cases of nosocomial ventilator-associated pneumonia.
Vo AT, van Duijkeren E, Fluit AC, Gaastra W.The aim of the present study was to contribute to the knowledge on extended-spectrum beta-lactamases (ESBL's), AmpC beta-lactamases and integrons in Enterobacteriaceae isolated from horses, which is still limited. The susceptibility of 1581 clinical isolates from animals to ceftiofur was tested. Most of these isolates (n=1347) originated from horses. Seven ceftiofur-resistant equine isolates (four Escherichia coli and three Klebsiella pneumoniae) were identified and all seven were multidrug-resistant. These isolates were further studied for the presence of ESBL's, AmpC beta-lactamases and clas...
Venner M, Heyers P, Strutzberg-Minder K, Lorenz N, Verspohl J, Klug E.The goal of the present study was to investigate whether new PCR-methods would improve diagnostic of R. equi. In a first step, sensitivity and specificity of the PCR-methods in respect to the"gold standard" microbiological culture were determined. Secondly, sensitivity and specificity of both microbiological methods were evaluated in respect to the clinical diagnosis. The tracheobronchial secretions of 48 foals with pulmonary abscesses and of 37 healthy foals were evaluated by bacteriological culture as well as by four PCR-methods: aceA-, ideR-, vapA- and VP-PCR. In respect to the"gold standar...
Jacks S, Giguère S, Crawford PC, Castleman WL.Rhodococcus equi is a facultative intracellular pathogen that causes pneumonia in young foals but does not induce disease in immunocompetent adult horses. Clearance of R. equi depends mainly on gamma interferon (IFN-gamma) production by T lymphocytes, whereas the predominance of interleukin 4 (IL-4) is detrimental. Young foals, like neonates of many other species, are generally deficient in the ability to produce IFN-gamma. The objective of this study was to compare the cytokine profiles, as well as cell-mediated and antibody responses, of young foals to those of adult horses following intrabr...
Parsons CS, Orsini JA, Krafty R, Capewell L, Boston R.To identify risk factors for development of acute laminitis in horses during hospitalization for illness or injury. Methods: Retrospective case-control study. Methods: 73 horses that developed laminitis (case horses) and 146 horses that did not develop laminitis (control horses) during hospitalization. Methods: Case and control horses were matched in a 2:1 ratio by the date on which each horse was evaluated. Potential risk factors investigated included age, breed, and sex; highest and lowest values recorded during hospitalization for fibrinogen concentration, WBC count, PCV, and total solids c...
Tomlinson JE, Reef VB, Boston RC, Johnson AL.Fibrinous parapneumonic pleural effusions are associated with decreased efficacy of pleural fluid drainage and increased risk of medical treatment failure in people, but similar associations have not been established in horses. Objective: We hypothesized that fibrin deposition in the pleural cavity of horses with parapneumonic effusions increases the risk of poor outcome. Methods: Seventy four horses with bacterial pleuropneumonia diagnosed by culture and cytology of tracheal aspirates, pleural fluid, or both, and pleural effusion diagnosed by ultrasonographic examination. Methods: Retrospecti...
Carr EA, Carlson GP, Wilson WD, Read DH.To characterize history, clinical signs, and pathologic findings in horses with histologically confirmed acute hemorrhagic pulmonary infarction and necrotizing pneumonia. Methods: Retrospective study. Methods: 21 horses. Results: 19 of the 21 horses were Thoroughbred racehorses in training. Eighteen horses had had strenuous exercise immediately prior to onset of illness. Fifteen horses had a serosanguineous nasal discharge during hospitalization. Seventeen horses had radiographic evidence of pulmonary consolidation and pleural effusion. Nine of 14 horses had ultrasonographic evidence of large ...
Prescott JF, Hoffman AM.This article summarizes recent advances in understanding of the epidemiology, pathogenesis, clinical and laboratory diagnosis, immunology, treatment, and control of Rhodococcus equi infections in foals. Our understanding of these aspects currently is sufficient to ensure control of this problem on affected farms and in infected foals. More information, however, is needed on factors predisposing foals to R. equi pneumonia, in particular, the nature of the naturally occurring cellular immunodeficiency in foals of 2 to 4 months of age, which also predisposes them to severe respiratory infection w...
Byars TD, Becht JL.The historical, clinical, diagnostic, and therapeutic aspects of pleuropneumonia are reviewed with emphasis placed on aggressive treatment and ultrasound diagnosis. The common sequelae are described, and appropriate treatment recommendations are included. A favorable prognosis may be expected for horses receiving long-term treatment.
Kuskie KR, Smith JL, Wang N, Carter CN, Chaffin MK, Slovis NM, Stepusin RS, Cattoi AE, Takai S, Cohen ND.To determine whether airborne concentrations of virulent Rhodococcus equi at 2 horse breeding farms varied on the basis of location, time of day, and month. Methods: 2 farms in central Kentucky with recurrent R equi-induced pneumonia in foals. Methods: From February through July 2008, air samples were collected hourly for a 24-hour period each month from stalls and paddocks used to house mares and their foals. Concentrations of airborne virulent R equi were determined via a modified colony immunoblot technique. Differences were compared by use of zero-inflated negative binomial methods to dete...
Rendle DI, Armstrong SK, Hughes KJ.This report documents the treatment of a case of chronic pleuropneumonia in a 3-year-old Thoroughbred gelding. A recombinant tissue plasminogen activator (tenecteplase) and a recombinant deoxyribonucleic acidase (alphadornase) were infused into the pleural cavity as adjunctive therapy in the early stages of treatment. Instillation of fibrinolytic drugs was associated with a subjective reduction in the amount of fibrin deposition and decreased fluid accumulation within the pleural cavities. Fibrinolytic therapy may be a useful adjunctive therapy in selected cases of intrapleural disease in hors...
Tate LP, Blikslager AT, Little ED.Guttural pouch tympanites was diagnosed in eight foals with respiratory stridor and tympanic swelling in the parotid region. Three foals were treated by transendoscopic neodymium:yttrium aluminum garnet (Nd:YAG) laser fenestration of the median septum between the guttural pouches. One foal died of pneumonia, and the other two foals recovered completely, although the fenestration later closed in one foal. Five foals were treated by creating a salpingopharyngeal fistula using transendoscopic laser irradiation; complete resolution of the tympanites occurred. Transendoscopic laser surgery in stand...
Dunowska M, Hardcastle MR, Tonkin FB.A 10-year-old polo mare presented with a history of weight loss, poor condition and inappetance. Results: The mare was tachycardic, tachypnoeic and febrile. Harsh lung sounds were auscultated over all lung fields. The mare initially responded to treatment with antibiotics, anti-inflammatory drugs and bronchodilators. Throughout the course of treatment, there was a variable lymphocytosis, monocytosis and fluctuation in concentrations of fibrinogen. The mare also developed a mild anaemia, most likely due to chronic disease. Despite treatment, the mare's condition deteriorated over the following ...
Giguère S, Hernandez J, Gaskin J, Prescott JF, Takai S, Miller C.The performance of four enzyme-linked immunosorbent assays (ELISAs) (ELISA-6939, ELISA-33701, ELISA-VapA, and ELISA-California) and an agar gel immunodiffusion test for diagnosis of Rhodococcus equi pneumonia in foals was evaluated. Antibody concentrations of foals with culture-confirmed R. equi pneumonia (n = 41) were compared to those of age-matched pasturemates that remained clinically healthy during the entire breeding season (n = 24). For each serological assay evaluated, selection of a low cutoff resulted in high sensitivity but low specificity. Increasing the cutoff value resulted in be...
Racklyeft DJ, Love DN.Twenty four normal, confined mares were unable to lower their heads for 24 or 48 h. In 21 mares this resulted in increases in the proportion of neutrophils and/or numbers of bacteria in transtracheal aspirates. In eight mares the changes in tracheal washes were accompanied by clinical evidence of mild respiratory disease. In three additional cases respiratory signs were accompanied by systemic illness. These changes reversed once the mares were able to lower their heads. Haematological changes (absolute neutrophilia and/or hyperfibrinogenamia) were mild and occurred more commonly in horses res...
Villarino N, Martín-Jiménez T.Macrolides are used for treatment of pneumonia and extrapulmonary conditions caused by Rhodococcus equi. In foals, macrolides have an extraordinary capacity to accumulate in different lung tissue compartments. These drugs show unique pharmacokinetic features such as rapid and extensive distribution and long persistence in pulmonary epithelial lining fluid (PELF) and bronchoalveolar lavage (BAL) cells from foals. This article reviews the pharmacokinetic characteristics of erythromycin, azithromycin, clarithromycin, tulathromycin, telithromycin, gamithromycin, and tilmicosin in foals, with empha...
Kosch PC, Koterba AM, Coons TJ, Webb AI.Developments in evaluation of newborn foals with respiratory distress are discussed. Major causes of respiratory distress are outlined and discussed in terms of the similar respiratory signs exhibited by foals with this clinical syndrome. History, physical examination, clinical pathology, chest radiography and blood gas analyses are discussed as important elements of the evaluation of the condition of these foals. Foals with respiratory disease are grouped into three major categories on the basis of clinical signs and arterial blood gas profiles. The evaluation of foals with respiratory distre...
Mutimer MD, Prescott JF, Woolcock JB.One hundred strains of Rhodococcus equi from various animal species and sources in Australia were examined for capsular serotype. Eighty-four of the strains fell into the existing 7 serotypes, and just under half of the strains belonged to serotype 1. Isolates from the intestines and faeces of horses, cattle, pigs and other species, and from soil, were found to belong to the same serotypes as those recovered from the lungs of foals with R. equi pneumonia. There was no clear relationships between capsular serotype and source of origin of the isolates.
Vengust M, Staempfli H, Prescott JF.A 10-year-old warmblood gelding was evaluated for intermittent pyrexia, dullness, weight loss, and progressive respiratory disease. Multifocal necrotic pneumonia and pleuritis due to Rhodococcus equi infection was diagnosed. Case management is discussed, as well as factors that may have led to this rare cause of pleuropneumonia in an adult horse.
Huber L, Giguère S, Berghaus LJ, Hanafi A, Ryan C.Rhodococcus equi, a soil saprophyte, is a common cause of pneumonia in foals and a frequent opportunistic pathogen in immunosuppressed people. Because it is widespread in the environment, R. equi can be detected in the feces of most horses. However, the exact timing and rate of shedding relative to infection is unknown. The objectives of this study were to quantify shedding of R. equi in mares and foals after experimental infection of foals with 2 different inocula and to determine the effect of composting on concentrations of R. equi in contaminated bedding. Foals were infected intratracheall...
Bedenice D, Heuwieser W, Brawer R, Solano M, Rand W, Paradis MR.A total of 207 thoracic radiographs obtained from 128 foals were evaluated to assess the impact of pulmonary radiographic pattern, distribution, and severity of pulmonary changes on short-term survival of neonatal foals. The association between selected clinical variables and the radiographic manifestation of neonatal respiratory disease was also investigated. The evaluation of interstitial and alveolar-interstitial radiographic patterns within the caudodorsal, caudoventral, and cranioventral lung regions proved to be highly reliable between viewers in the study. A diagnosis of systemic inflam...
Takai S, Murata N, Kudo R, Narematsu N, Kakuda T, Sasaki Y, Tsubaki S.This report describes the discovery of two new virulence plasmid types from a crossbred foal with Rhodococcus equi pneumonia in Kumamoto died with severe R. equi pneumonia and ulcerative enteritis. R. equi was isolated in large numbers and isolates from the foal were investigated for the presence of virulence-associated 15-17 kDa antigens (VapA) by colony blotting, using the monoclonal antibody 10G5, and by gene coding for VapA by PCR. Plasmid DNAs extracted from the isolates were digested with restriction endonucleases BamHI, EcoRI, EcoT22I, and HindIII. The digestion patterns that resulted d...
Schlusselhuber M, Guldbech K, Sevin C, Leippe M, Petry S, Grötzinger J, Giguère S, Cauchard J.The equine antimicrobial peptide eCATH1 previously has been shown to have in vitro activity against antibiotic-susceptible reference strains of Rhodococcus equi and common respiratory bacterial pathogens of foals. Interestingly, eCATH1 was also found to be effective in the treatment of R. equi infection induced in mice. The aim of this study was to assess the in vitro activity of eCATH1 against equine isolates of Gram-negative (Escherichia coli, Salmonella enterica, Klebsiella pneumoniae and Pseudomonas spp.) and Gram-positive (R. equi, Staphylococcus aureus) bacteria resistant to multiple cla...
Huber L, Giguère S, Hart KA, Slovis NM, Greiter ME, Dailey CA, Cohen ND.To compare soil concentrations of macrolide- and rifampicin-resistant strains (MRRE) on horse-breeding farms that used thoracic ultrasonographic screening (TUS) to identify foals with subclinical pneumonia combined with subsequent administration of macrolides and rifampin to affected foals (TUS farms) versus soil concentrations on farms that did not (non-TUS farms), determine whether the combined use of TUS and antimicrobial treatment of subclinically affected foals was associated with soil concentration of MRRE, and assess whether there were temporal effects on soil concentrations of MRRE du...
Chaffin MK, Cohen ND, Martens RJ.To identify farm characteristics as risk factors for the development of Rhodococcus equi pneumonia in foals. Methods: Prospective matched case-control study. Methods: 2,764 foals on 64 equine breeding farms with 9,991 horses. Methods: During 1997, participating veterinarians completed paired data collection forms, 1 for a farm with > or = 1 foal with R equi pneumonia and 1 for an unaffected control farm. Matched data were compared by use of conditional logistic regression analysis. Results: Farm characteristics found in bivariate analyses to be associated with increased risk for pneumonia caus...
Bianchi MV, Mello LS, Ribeiro PR, Wentz MF, Stolf AS, Lopes BC, de Andrade CP, Snel GGM, Sonne L, Driemeier D, Pavarini SP.We document the causes and pathological findings in 50 cases of equine pneumonia and pleuritis in Southern Brazil. Suppurative (17/50), pyogranulomatous (14/50), aspiration (5/50), mycotic (4/50), bronchointerstitial (3/50), embolic (3/50) and eosinophilic granulomatous pneumonia (1/50) and pleuritis (3/50) were the main conditions identified. Streptococcus spp. were identified in 11 cases of suppurative pneumonia. Suppurative pneumonia was further divided into acute (8/17), subacute (6/17) and chronic (3/17) based on the morphological pattern of lesions. Rhodococcus equi was identified in all...
Kahn SK, Cohen ND, Bordin AI, Coleman MC, Heird JC, Welsh TH.The bacterium Rhodococcus equi causes pneumonia in foals that is prevalent at breeding farms worldwide. In the absence of an effective vaccine, transfusion of commercial plasma from donor horses hyperimmunised against R. equi is used by many farms to reduce the incidence of pneumonia among foals at farms where the disease is endemic. The effectiveness of hyperimmune plasma for controlling R. equi pneumonia in foals has varied considerably among reports. The purposes of this narrative review are: (1) to review early studies that provided a foundational basis for the practice of transfusion of h...
The Journal of hygieneDecember 1, 1976
Volume 77, Issue 3 401-408 doi: 10.1017/s0022172400055789
Platt H, Atherton JG, Orskov I.An account is given of K. pneumoniae capsule types occurring in horses, with particular reference to strains originating from the genital tract in the mare and the external genitalia of the stallion. A survey of the prevalence of K. pneumoniae and E. aerogenes strains in the preputial flora of healthy stallions is described. The majority of horses were found to be carriers of these organisms. The cultural characteristics of these preputial strains are described and compared with those of K. pneumoniae strains associated with epidemic metritis in mares. The epidemiological significance of certa...
Makrai L, Fodor L, Csivincsik A, Varga J, Senoner Z, Szabó B.The cultural, morphological, biochemical, serological characteristics and antibiotic susceptibility of 25 Rhodococcus equi strains isolated from lungs and lung abscesses of pneumonic foals and 5 R. equi strains isolated from immuno-compromised human patients were examined. All R. equi strains showed common cultural, morphological and biochemical characteristics both with conventional tests and on the basis of their enzyme profile. The R. equi strains examined were resistant to penicillins with the exception of ampicillin, to sulphamethazine and several strains also to sulphamethoxazole-trimeth...
Bolton T, Kuskie K, Halbert N, Chaffin K, Healy M, Lawhon S, Jackson A, Cohen N.Rhodococcus equi is an important pathogen of foals aged 1-6 months. Evidence exists that foals are exposed to a wide diversity of R. equi strains in their environment. However, limited data are available regarding the extent to which genotypic variation exists among isolates infecting individual foals. Therefore, electrophoresis of repetitive sequence-based polymerase chain reaction (rep-PCR) amplicons in an automated microfluidics chip format was used to genotype 9 virulent R. equi isolates obtained from distinct anatomic locations in a single foal. Four of the isolates were obtained from dif...
Kushugulova A, Löber U, Akpanova S, Rysbekov K, Kozhakhmetov S, Khassenbekova Z, Essex M, Nurgozhina A, Nurgaziyev M, Babenko D, Markó L....Probiotics and prebiotics are widely used for recovery of the human gut microbiome after antibiotic treatment. High antibiotic usage is especially common in children with developing microbiome. We hypothesized that dry Mare's milk, which is rich in biologically active substances without containing live bacteria, could be used as a prebiotic in promoting microbial diversity following antibiotic treatment in children. The present pilot study aims to determine the impacts of dry Mare's milk on the diversity of gut bacterial communities when administered during antibiotic treatment and throughout ...
McQueen CM, Whitfield-Cargile CM, Konganti K, Blodgett GP, Dindot SV, Cohen ND.Rhodococcus equi (R. equi) is an intracellular bacterium that affects young foals and immuno-compromised individuals causing severe pneumonia. Currently, the genetic mechanisms that confer susceptibility and/or resistance to R. equi are not fully understood. Previously, using a SNP-based genome-wide association study, we identified a region on equine chromosome 26 associated with culture-confirmed clinical pneumonia. To better characterize this region and understand the function of the SNP located within TRPM2 that was associated with R. equi pneumonia, we performed RNA-Seq on 12 horses repres...
Wadsworth AB, Kirkbride MB.Horses immunized to Type I pneumococci developed serum, 0.1 cc. of which protected against 0.5 cc. of a virulent culture, 0.000001 cc. of which killed mice in less than 40 hours. Protective tests of serum from horses immunized to Type II organisms varied, 0.1 cc. protecting, however, in certain instances against 0.1 and 0.01 cc. of virulent homologous culture. Types I and II sera obtained in our experiments with culture sediment and whole culture did not vary markedly for a given type and corresponded closely in their protective titer with samples of sera received from The Rockefeller Institut...
