Respiratory disease in horses encompasses a range of conditions affecting the respiratory system, including the upper and lower airways. These diseases can result from various etiologies such as infectious agents, environmental factors, or genetic predispositions. Common respiratory conditions in horses include equine asthma, equine influenza, and strangles. Clinical signs often associated with respiratory disease in horses include coughing, nasal discharge, and labored breathing. Diagnostic approaches may involve endoscopy, imaging, and laboratory tests to assess the function and health of the respiratory tract. This page compiles peer-reviewed research studies and scholarly articles that explore the pathophysiology, diagnosis, and management of respiratory diseases in equine populations.
Sander SJ, Joyner PH, Cray C, Rotstein DS, Aitken-Palmer C.Acute phase proteins are sensitive markers of inflammation, which are highly conserved across taxa. Although the utility of these proteins are becoming well defined in human and domestic animal medical fields, their role in nondomestic species remains unclear. In this communication, a 20-yr-old Przewalski's horse was presented for unresolving aspiration pneumonia, which cultured a unique Actinomyces-like bacteria. Despite waxing and waning clinical signs and minimal changes on baseline hematologic analysis, protein electrophoresis, serum amyloid A, and surfactant protein D serum concentrations...
Lee J, Park JH, Min JY.The non-structural protein of influenza A virus (NS1A protein) is a multifunctional protein that antagonizes host antiviral responses and contributes to efficient viral replication during infection. However, most of its functions have been elucidated by generating recombinant viruses expressing mutated NS1 proteins that do not exist in nature. Recently, the novel H3N8 A/Equine/Kyonggi/SA1/2011 (KG11) influenza virus was isolated in Korea from horses showing respiratory disease symptoms. KG11 virus contains a naturally truncated NS gene segment with the truncation in the NS1A coding region, res...
Barussi FC, Bastos FZ, Leite LM, Fragoso FY, Senegaglia AC, Brofman PR, Nishiyama A, Pimpão CT, Michelotto PV.This research evaluated the effects of bone marrow-derived mononuclear cells (BMMCs) on the inflammatory process in the equine recurrent airway obstruction (RAO). Eight horses in RAO clinical score were divided into cell therapy group (Gcel) treated with a single intratracheal dose of BMMCs, and dexamethasone group (Gdex) treated with 21days of oral dexamethasone. The horses were clinically revaluated on days 7 and 21, together with cytological evaluation of the BALF, and detection of inflammatory markers (interleukins [IL]-10, -4, and -17, and interferon γ and α). There were decreases in re...
Schöniger S, Roschanski N, Rösler U, Vidovic A, Nowak M, Dietz O, Wittenbrink MM, Schoon HA.Pyogranulomatous rhinitis associated with an algal infection was diagnosed in a 25-year-old gelding and a 23-year-old mare had necrotizing sinusitis with intralesional algae and pigmented fungi. Algae were identified immunohistochemically in both cases as Prototheca spp. In the gelding, further characterization by polymerase chain reaction and sequencing revealed that the organism was Prototheca zopfii genotype 2. Fungi from the mare were identified as Pithomyces chartarum by molecular analysis. Prototheca species are achlorophyllous algae and P. chartarum represents a dematiaceous fungus; the...
Marr CM.Respiratory and cardiac diseases are common in older horses. Advancing age is a specific risk factor for cardiac murmurs and these are more likely in males and small horses. Airway inflammation is the most common respiratory diagnosis. Recurrent airway obstruction can lead to irreversible structural change and bronchiectasis; with chronic hypoxia, right heart dysfunction and failure can develop. Valvular heart disease most often affects the aortic and/or the mitral valve. Management of comorbidity is an essential element of the therapeutic approach to cardiac and respiratory disease in older e...
Pirie RS, Couëtil LL, Robinson NE, Lavoie JP.In their editorial in Equine Veterinary Journal (EVJ) almost a quarter of a
century ago, Hall and Stark [1] referred to the inability of clinicians, both
human and veterinary, to separate and recognise the different clinical
entities responsible for chronic diseases of the airways, with the
subsequent development of several different approaches to terminology,
as well as treatment. In relation to equine nonseptic lower airway disease,
and despite many attempts to identify the most appropriate nomenclature,
this challenge remains as topical today as it did then. ‘Equine asthma’ has
...
Arroyo MG, Couëtil LL, Nogradi N, Kamarudin MM, Ivester KM.The (R)-enantiomer of racemic albuterol (levalbuterol) has bronchodilatory properties whereas the (S)-enantiomer causes adverse effects in human airways, animal models, and isolated equine bronchi. Levalbuterol is commercially available and improves pulmonary function of asthmatic patients with a longer duration of effect than albuterol. Objective: To determine the dose at which inhaled levalbuterol produces maximal bronchodilatory effect (EDmax) and determine its duration of action in recurrent airway obstruction (RAO)-affected horses in comparison to racemic albuterol. Methods: Nine horses w...
Niedzwiedz A, Borowicz H, Januszewska L, Markiewicz-Gorka I, Jaworski Z.It has been reported that equine recurrent airway obstruction (RAO) is a state of oxidative stress. Oxidant-antioxidant imbalance is known to increase the conversion of deoxyguanosine to 8-hydroxy-2-deoxyguanosine (8-OHdG) in DNA. 8-OHdG can easily be measured using ELISA tests in serum or urine samples. In this study, we analysed serum 8-OHdG levels in horses with recurrent airway obstruction and in healthy controls. Results: The study material consisted of seven healthy horses and seven horses with symptomatic RAO. All horses were exposed to moldy hay and straw for 48 h to induce clinical e...
Viscardi V, Jorge ML, Silva KM, Sad EP, Fonseca AB, Alencar NX, Lessa DA.Collection of fluid from the lower respiratory tract (LRT) plays an important role in both the pathophysiological investigation and diagnosis of respiratory tract disease. Enzymes such as ALP are, among others, indicators of cell damage or death, type II pneumocyte proliferation, and neutrophil invasion, and have been useful as biomarkers of respiratory disease in other species. Objective: The purpose of this study was to determine and compare tracheal wash (TW) ALP activity in healthy horses and horses with LRT inflammation (LRTI) determined by TW cytology profile. Methods: Tracheal washes we...
Murcia RY, Vargas A, Lavoie JP.Glucocorticoids (GCs) are the most effective drugs for the treatment of human asthma. However, a subgroup of asthmatic patients with neutrophilic airway inflammation is insensitive to GCs. Interleukin-17 (IL-17), a cytokine upregulated in the airways of a subset of human asthmatic patients, contributes to the recruitment of neutrophils and induces a glucocorticoid resistance in human airway epithelial cells. We hypothesized that IL-17 similarly activates neutrophils and contributes to their persistence in the asthmatic airways in spite of glucocorticoid therapy. To determine whether IL-17 dire...
Zhao J, Negussie H, Laval K, Poelaert KC, Nauwynck HJ.Equine herpesvirus 1 (EHV-1) and equine arteritis virus (EAV) induce respiratory problems and abortion in horses and are considered as two serious threats to equine industry. Both EHV-1 and EAV misuse patrolling leukocytes in the upper respiratory tract to breach the basement membrane (BM) and to migrate to blood vessels. So far, the behavior and impact of a double infection in the respiratory mucosa of a horse are unknown. In the present study, the outcome of double infections with EHV-1 and the low virulent EAV strain 08P187 (superinfection with an interval of 12h or co-infection) were compa...
Careddu GM, Evangelisti MA, Columbano N, Masala G, Manunta ML, Passino ES.Progressive ethmoid hematoma is frequently reported among the pathologies of the upper airways in horses. While several hypotheses have been proposed such as repeated trauma, inflammatory processes and/or chronic infections, congenital phenomena, complication of hemangiomas, and neoplastic processes, the aetiology of this condition is yet unknown. Clinical symptoms are non-specific and includes haemorrhagic nasal discharge, respiratory noise not related to physical exercise and, in most severe cases, phenomena of coughing. The purpose of this case report is to contribute to a correct diagnosti...
Giles C, Ndi O, Barton MD, Vanniasinkam T.Rhodococcus equi is a respiratory pathogen which primarily infects foals and is endemic on farms around the world with 50% mortality and 80% morbidity in affected foals. Unless detected early and treated appropriately the disease can be fatal. Currently, there is no vaccine available to prevent this disease. For decades researchers have endeavoured to develop an effective vaccine to no avail. In this study a novel human adenoviral vector vaccine for R. equi was developed and tested in the mouse model. This vaccine generated a strong antibody and cytokine response and clearance of R. equi was d...
Kováts N, Horváth E, Jancsek-Turóczi B, Hoffer A, Gelencsér A, Urbán P, Kiss ÍE, Bihari Z, Fekete C.Air quality in the stables is characterized by elevated level of dust and aeroallergens which are supposed to directly cause or exacerbate several respiratory disorders. The most often recognized problem is recurrent airway obstruction (RAO), previously known as chronic obstructive pulmonary disease (COPD). There is some indication that aeroallergens (among them endotoxins) may also cause inflammation in human airways and may exceed safe levels in stables. Monitoring studies have covered mainly the determination of the concentration of respirable particles and of culturable fungi and their tox...
Hue ES, Fortier CI, Laurent AM, Quesnelle YF, Fortier GD, Legrand LJ, Pronost SL.The protocol describes a quantitative RT-PCR method for the detection and quantification of EHV-2 in equine respiratory fluids according to the NF U47-600 norm. After the development and first validation step, two distinct characterization steps were performed according to the AFNOR norm: (a) characterization of the qRT-PCR assay alone and (b) characterization of the whole analytical method. The validation of the whole analytical method included the portrayal of all steps between the extraction of nucleic acids and the final PCR analysis. Validation of the whole method is very important for vi...
Hurley MJ, Riggs CM, Cogger N, Rosanowski SM.A 2 year prospective study was performed between February 2011 and January 2013 to determine the incidence and risk factors for shipping fever (SF) in horses transported by air to Hong Kong (HK). Using a questionnaire, data were collected from professional flying grooms regarding the journey to HK and horses in the shipment. Horses were monitored in quarantine for 2 weeks after arrival in HK, and clinical signs of SF recorded. Poisson and logistic regression models were used to identify risk factors for SF at the horse and shipment levels. The study analysed data from 869 horses on 81 flights ...
Taylor AH, Seymour CJ.Horses may become hypoxaemic during anaesthesia despite a high inspired oxygen fraction (FiO2). A lower FiO2 is used commonly in human beings to minimise atelectasis and to improve lung function, and previously has been shown to be of potential benefit in horses in experimental conditions. Other studies suggest no benefit to using a FiO2 of 0.5 during clinically relevant conditions; however, low FiO2 (0.65) is commonly used in practice and in a large number of studies. The present study was performed to compare the effect of a commonly used FiO2 of 0.65 versus 0.90 on calculated respiratory in...
Herteman N, Bullone M, Lavoie JP.Heaves is a severe debilitating condition of horses, characterized by lower airway inflammation and permanent structural changes of the bronchial wall. Chronic inflammation promotes the formation of new vessels, a phenomenon known as angiogenesis. Narrow band imaging (NBI) endoscopy is a noninvasive technique that enhances the visualization of submucosal vessels, and commonly is employed for the study of angiogenesis in human patients. Objective: Using NBI, we aimed to determine whether or not the central airways of horses with heaves undergo angiogenesis. Methods: Horses with heaves during ex...
Ghosh S, Das PJ, McQueen CM, Gerber V, Swiderski CE, Lavoie JP, Chowdhary BP, Raudsepp T.We explored the involvement of genomic copy number variants (CNVs) in susceptibility to recurrent airway obstruction (RAO), or heaves-an asthmalike inflammatory disease in horses. Analysis of 16 RAO-susceptible (cases) and six RAO-resistant (control) horses on a custom-made whole-genome 400K equine tiling array identified 245 CNV regions (CNVRs), 197 previously known and 48 new, distributed on all horse autosomes and the X chromosome. Among the new CNVRs, 30 were exclusively found in RAO cases and were further analyzed by quantitative PCR, including additional cases and controls. Suggestive as...
Allano M, Labrecque O, Rodriguez Batista E, Beauchamp G, Bédard C, Lavoie JP, Leclere M.The aim of this study was to determine the effects of short distance transportation on airway mucus, cytology and bacterial culture to identify potential biases in the diagnosis of airway diseases in referral centres. Eight healthy adult horses were studied using a prospective cross-over design. Mucus scores, tracheal wash (cytology, bacterial culture) and bronchoalveolar lavage fluid (BALF; cytology) were obtained while stabled and following 2.5 h transportation (with and without hay). Neutrophil counts, percentages and BALF neutrophilia frequency increased following transport without hay (...
Bullone M, Murcia RY, Lavoie JP.Clinical exacerbations of severe equine asthma (formerly recurrent airway obstruction [RAO]) are more frequently reported during winter when horses are exposed to airborne dusts during stabling. However, we have also observed a worsening of clinical signs on days during a heatwave. Objective: To investigate the association between environmental temperature and humidity and clinical signs of asthma in horses during clinical exacerbation of the disease. Methods: Retrospective longitudinal study. Methods: Historical data on 14 severe asthmatic horses exposed to a dusty environment and evaluated u...
Rocha JN, Cohen ND, Bordin AI, Brake CN, Giguère S, Coleman MC, Alaniz RC, Lawhon SD, Mwangi W, Pillai SD.There is currently no licensed vaccine that protects foals against Rhodococcus equi-induced pneumonia. Oral administration of live, virulent R. equi to neonatal foals has been demonstrated to protect against subsequent intrabronchial challenge with virulent R. equi. Electron beam (eBeam)-inactivated R. equi are structurally intact and have been demonstrated to be immunogenic when administered orally to neonatal foals. Thus, we investigated whether eBeam inactivated R. equi could protect foals against developing pneumonia after experimental infection with live, virulent R. equi. Foals (n = 8) w...
Lühe T, Mielenz N, Schulz J, Dreyer-Rendelsmann C, Kemper N.Environmental factors contribute to respiratory diseases in horses and man. During exercise, equine ventilation is increased, potentially increasing exposure of the airways to inhaled particulates. Currently, there is very little information on the quality of air in riding arenas. Objective: To evaluate air quality and dust particle concentrations in indoor riding arenas before and after use for riding. Methods: Longitudinal study. Methods: Air quality was assessed in 4 indoor riding arenas in Saxony-Anhalt, Germany on a monthly basis for 1 year. Concentrations of particles in 6 particle fract...
Madrigal RG, Shaw SD, Witkowski LA, Sisson BE, Blodgett GP, Chaffin MK, Cohen ND.Current screening tests for Rhodococcus equi pneumonia in foals lack adequate accuracy for clinical use. Real-time, quantitative PCR (qPCR) for virulent R. equi in feces has not been systematically evaluated as a screening test. Objective: The objective of this study was to evaluate the accuracy of qPCR for vapA in serially collected fecal samples as a screening test for R. equi pneumonia in foals. Methods: One hundred and twenty-five foals born in 2011 at a ranch in Texas. Methods: Fecal samples were collected concurrently with thoracic ultrasonography (TUS) screening examinations at ages 3, ...
Cohen ND, Giguère S, Burton AJ, Rocha JN, Berghaus LJ, Brake CN, Bordin AI, Coleman MC.Adverse effects of, and bacterial resistance to, macrolides used to treat Rhodococcus equi infections have prompted search for clinically effective alternative antimicrobials. Liposomal gentamicin (LG) is effective against R. equi in vitro and decreases tissue concentrations of R. equi in experimentally infected mice. Effectiveness of LG treatment of foals with R. equi pneumonia, however, has not been described. Objective: Liposomal gentamicin is safe and effective for treating foals with R. equi pneumonia. Methods: Ten foals with experimentally induced R. equi pneumonia. Methods: Pilot treatm...
Back H, Berndtsson LT, Gröndahl G, Ståhl K, Pringle J, Zohari S.Equine Influenza Virus (EIV) is a major cause of respiratory disease in horses and the virus constantly undergoes antigenic drift. Here we characterize and describe the HA1 and the NA genes of H3N8 within samples obtained from outbreaks in Sweden during November-December 2011. Both clade 1 and clade 2 viruses of the Florida sublineage were identified. The index case of clade 2 was transported to Sweden from Spain through the Netherlands, whereas the clade 1 had its origin from a Swedish stud farm. The clade 1 virus was efficiently spread between training yards by unvaccinated young horses, but...
Padalino B, Hall E, Raidal S, Celi P, Knight P, Jeffcott L, Muscatello G.Equine transportation is associated with a variety of serious health disorders causing economic losses. However; statistics on horse transport are limited and epidemiological data on transport related diseases are available only for horses transported to abattoirs for slaughter. This study analysed reports of transport related health problems identified by drivers and horse owners for 180 journeys of an Australian horse transport company transporting horses between Perth and Sydney (~4000 km) in 2013-2015. Records showed that 97.2% (1604/1650) of the horses arrived at their destination with no...
Mitlehner W, Mitlehner HC, Niggemann B.To test the hypothesis that so called hypoallergenic horses (Curly horses) allow horse allergic riders to ride again, we investigated 40 horse allergic riders in a period of 37 months. We tested these patients (pts.) by skin prick test (SPT) with different non-curly and Curly horses and studied the riding hours and horse brushing by measurements of peak expiratory flow (PEF) and Tiffeneau tests (FEV1) as well as peak nasal inspiratory flow (PNIF) over 12 months. The results in 37/40 pts. showed no relevant reactions of the lower airways or nasal flow. Only in 3/40 patients an initial signific...
Barton AK, Shety T, Bondzio A, Einspanier R, Gehlen H.In chronic respiratory disease, matrix metalloproteinases (MMPs) contribute to pathological tissue destruction when expressed in excess, while tissue inhibitors of metalloproteinases (TIMPs) counteract MMPs with overexpression leading to fibrosis formation. They may be out of balance in equine pneumopathies and serve as biomarkers of pulmonary inflammation. We hypothesized that MMPs and TIMPs correlate to clinical findings and bronchoalveolar lavage fluid cytology in different equine chronic pneumopathies. Using a scoring system, 61 horses were classified controls as free of respiratory diseas...
Wysocka B, Kluciński W.The aim of the present study was to compare the grade of discharge accumulation in the tracheal lumen, area of tracheal bifurcation, main bronchi and the tracheal septum thickness with the cytology of the tracheal aspirate (TA) and broncho-alveolar lavage fluid (BALF) in horses with recurrent airways obstruction and inflammatory airway disease from those horses. This study was conducted on 96 horses with RAO, 139 horses with IAD and 10 control horses. In all the horses, both clinical and endoscopic examinations were performed. During endoscopy, a score of mucus accumulation was estimated in 3/...
Couëtil LL, Art T, de Moffarts B, Becker M, Mélotte D, Jaspar F, Bureau F, Lekeux P.Horses with recurrent airway obstruction (RAO) present many similarities with human asthmatics including airway inflammation, hyperresponsiveness, reversible obstruction, and increased NF-kappaB expression. Studies in experimental asthma models have shown that transcriptions factors such as activator protein-1 (AP-1), GATA-3, cyclic AMP response element binding protein (CREB) and CAAT/enhancer binding protein (C/EBP) may also play an important role in airway inflammation. The purpose of this study was to measure DNA binding activity of these transcription factors in the airways of horses with ...
Goodman LB, Anderson RR, Slater M, Ortenberg E, Renshaw RW, Chilson BD, Laverack MA, Beeby JS, Dubovi EJ, Glaser AL.Nanoliter scale real-time PCR uses spatial multiplexing to allow multiple assays to be run in parallel on a single plate without the typical drawbacks of combining reactions together. We designed and evaluated a panel based on this principle to rapidly identify the presence of common disease agents in dogs and horses with acute respiratory illness. This manuscript describes a nanoscale diagnostic PCR workflow for sample preparation, amplification, and analysis of target pathogen sequences, focusing on procedures that are different from microliter scale reactions. In the respiratory panel prese...
Sellon DC, Walker K, Suyemoto M, Altier C.To evaluate the ability of nucleic acid amplification techniques to detect Rhodococcus equi in equine buffy coat, blood, and tracheal wash fluid and to differentiate between virulent and avirulent strains of the bacteria. Methods: Blood anticoagulated with EDTA and tracheal wash fluid from healthy horses. Methods: Logarithmic dilutions of virulent and avirulent strains of R equi were added to equine buffy coat and tracheal wash fluid samples. The DNA was extracted and amplified by polymerase chain reaction (PCR), using primers specific for the 16S ribosomal subunit gene and the virulence plasm...
Briganti A, Portela DA, Grasso S, Sgorbini M, Tayari H, Bassini JR, Vitale V, Romano MS, Crovace A, Breghi G, Staffieri F.The aim of this study was to evaluate the correlation of commonly used oxygenation indices with venous admixture (Qs/Qt) in anaesthetised horses under different infusion rates of dobutamine. Six female horses were anaesthetised with acepromazine, xylazine, diazepam, ketamine, and isoflurane, and then intubated and mechanically ventilated with 100% O2. A Swan-Ganz catheter was introduced into the left jugular vein and its tip advanced into the pulmonary artery. Horses received different standardised rates of dobutamine. For each horse, eight samples of arterial and mixed venous blood were simul...
Pusterla N, James K, Barnum S, Delwart E.Three newly identified equine parvoviruses (equine parvovirus hepatitis (EqPV-H), equine parvovirus CSF (EqPV-CSF) and equine copivirus (Eqcopivirus)) have recently been discovered in horses with respiratory signs. However, the clinical impact of these three equine parvoviruses has yet to be determined. Nasal fluid samples and blood from 667 equids with acute onset of fever and respiratory signs submitted to a diagnostic laboratory were analyzed for the presence of common equine respiratory pathogens (equine influenza virus, equine herpesvirus-1/-4, equine rhinitis A and B virus, subspecies )...
Dunowska M, Meers J, Wilks CR.To report the first isolation of equine herpesvirus 5 (EHV-5) in New Zealand as part of a study of equine respiratory viruses in New Zealand. Methods: Nasal swabs and peripheral blood leukocytes were collected from 114 foals and adult horses, inoculated on to equine fetal kidney, rabbit kidney and Vero cell lines and observed for cytopathic effect. EHV-5 isolates were identified using an EHV-5 specific polymerase chain reaction. All samples positive for EHV-5 were also checked for the presence of EHV-2, EHV-1 or EHV-4 DNA using published type-specific primers. The polymerase chain reaction res...
Lynch SE, Gilkerson JR, Symes SJ, Huang JA, Hartley CA.Equine rhinitis A virus (ERAV) is a member of the Aphthovirus genus, and has many physical and structural similarities to the prototype Aphthovirus foot-and-mouth disease virus (FMDV). The pathogenesis of FMDV has been extensively studied, however, the similarities in the pathogenesis of ERAV and FMDV disease has not been well documented. This study describes and compares the pathogenesis of ERAV both in the natural host and a small animal model alternative (CBA mice). Distinct parallels in the pathogenesis of the acute infection of these two viruses are described where infection in the upper ...
Art T, Franck T, Lekeux P, de Moffarts B, Couëtil L, Becker M, Kohnen S, Deby-Dupont G, Serteyn D.The aim of this work was to measure the myeloperoxidase (MPO) concentration in bronchoalveolar lavage (BAL) fluid collected from horses with recurrent airway obstruction (RAO), both in crisis and in remission, as well as from healthy horses. Seven horses with RAO were exposed to moldy hay until the maximum change in pleural pressure was greater than 1.5 kPa. At that point, BAL was performed, and the total cell counts and percentages in the fluid were immediately determined. To measure the MPO concentration in BAL-fluid supernatant, we used a specific enzyme-linked immunosorbent assay with poly...
Borchers K, Wolfinger U, Ludwig H, Thein P, Baxi S, Field HJ, Slater JD.Two 18-month-old naturally reared ponies were used to investigate the pathogenicity of EHV-2. After dexamethasone treatment, pony 1 was inoculated intranasally with EHV-2 strain T16, which has been isolated from a foal with keratoconjunctivitis superficialis and pony 2 was similarly inoculated with strain LK4 which was originally isolated from a horse with upper respiratory tract disease. Following virus inoculation, pyrexia was not detected in either pony but both developed conjunctivitis, lymphadenopathy, and coughing. EHV-2 was detected in nasal mucus samples up to day 12 post infection (p....
Davis E, Rush BR.Recurrent airway obstruction is a condition that affects some older horses maintained in confinement. Clinical signs range from exercise intolerance with occasional cough to dyspnea at rest. Bronchoalveolar lavage cytology is characterized by neutrophilic leukocytosis (15%-85%) and is recommended for making the diagnosis in horses with mild to moderate disease. Environmental management combined with periodic bronchodilator and antiinflammatory corticosteroid therapy yields the best prognosis for disease remission.
Stewart AJ, Cuming RS.Fungal respiratory disease is a rare occurrence in horses. Fungal organisms are ubiquitous in the equine environment; however, there is a geographic predisposition for disease development, with fungal respiratory infections seen more commonly by practitioners working in tropical or subtropical environments. Diagnosis and treatment of fungal respiratory infections pose a challenge for the equine practitioner, and the prognosis for complete resolution of infection is often guarded; however, new antifungal medications are likely to improve treatment success. This article summarizes the available ...
Lapointe JM, Lavoie JP, Vrins AA.Effects of triamcinolone acetonide (TA) on pulmonary function, bronchoalveolar lavage cytologic features and serum cortisol concentration, were studied in 5 control horses and 5 horses with chronic obstructive pulmonary disease (COPD). In experiment 1, horses were brought in from pasture 3 weeks before administration of 1 injection of TA (0.09 mg/kg of body weight, IM), and were stabled in dusty conditions throughout the experimental period. Measurements of respiratory rate (f), tidal volume, minute ventilation, expiratory-to-inspiratory time ratio, maximal change in transpulmonary pressure (d...
COllinson PN, O'Rielly JL, Ficorilli N, Studdert MJ.Ocular problems characterized by conjunctivitis, epiphora, and keratopathy were detected in 35 of 80 Thoroughbred weanling foals that also had respiratory disease. Ocular problems were determined to be caused by infection with equine herpesvirus type 2 (EHV-2) and were successfully treated with ophthalmic medication containing idoxuridine. Equine herpesvirus type 2 isolated from 3 of 5 foals from which samples were collected. The identity of the causative virus as EHV-2 was confirmed by use of electron microscopy, restriction endonuclease DNA fingerprinting, and Southern blot analysis.
Lin C, Holland RE, Williams NM, Chambers TM.Equine nasal turbinate epithelial cells and tracheal rafts were maintained with sustained viability in culture. Both types of culture supported productive replication of equine influenza virus (equine-2, subtype H3N8) and cell death occurred through apoptosis following viral infection. Thus, primary respiratory epithelial cell and organ cultures of equine origin may be valuable as alternatives to the intact animal for studying the virus-host interaction of equine respiratory viruses including influenza.
Deaton CM.Equine recurrent airway obstruction (RAO) is a naturally occurring respiratory disease in horses with many similarities to human asthma and, as a result, has been used as an animal model of this disease. Oxidative stress has been demonstrated to occur in a range of respiratory diseases in human beings including asthma. Quantitatively, horses have a greater non-enzymatic antioxidant capacity in the pulmonary epithelial lining fluid compared to human beings due to high ascorbic acid concentrations, which reflects their ability to synthesise ascorbic acid. Consequently, a greater oxidative load i...
Swanberg JE, Clouser JM, Gan W, Mannino DM, Flunker JC.Latino workers are likely exposed to a variety of respiratory hazards in the horse barn, yet the potential impact of these exposures on respiratory health has not been investigated. Methods: Using a community-based sample of 225 Latino horse farmworkers we investigated the prevalence of upper and lower respiratory symptoms and occupational characteristics associated with them. Multivariable logistic regression was used to identify factors associated with respiratory symptomology. Results: Upper respiratory symptoms prevalence ranged from 24% to 45%. Half of workers reported lower respiratory s...
Liccardi G, Emenius G, Merritt AS, Salzillo A, D'Amato M, D'Amato G.Most studies on the sensitization to horse allergens in populations without professional exposure have been carried out in geographical areas where the rate of horse ownership is high and horse riding is popular. Very few studies have been carried out in populations living in large urban areas. This gap in the literature probably reflects the widespread view that prevalence of horse-related allergy is low in urban populations because the latter are not regularly exposed to horses. On the contrary, we suggest that urban areas constitute a model useful to study potential modalities of exposure a...
Jocelyn NA, Wylie CE, Lean M, Barrelet A, Foote AK.Tracheal wash sample neutrophilia is common in lower airway inflammation of various causes; however, relevance of cytomorphological features to culture of bacterial pathogens has not been established. Objective: To investigate whether the presence of nondegenerate or degenerate neutrophils in tracheal washes is associated with culture of bacteria and, if so, whether this is influenced by age or temporal factors. Methods: Cross-sectional study. Methods: Tracheal wash samples submitted to Rossdales LLP from 1/1/2013 to 31/7/2015 were evaluated using set criteria. Neutrophilia and degenerate neut...
Riihimäki M, Raine A, Pourazar J, Sandström T, Art T, Lekeux P, Couëtil L, Pringle J.The aim of this study was to evaluate the contribution of bronchial epithelium to airway inflammation, with focus on mRNA and protein expression of cytokines of innate immunity IL-6, IL-10 and TNF-alpha, in horses with Recurrent Airway Obstruction (RAO) during exacerbation and in remission. Results: Despite marked clinical and physiologic alterations between exacerbation and after remission in the RAO horses no differences were detected in either cytokine mRNA or protein levels. Moreover, the expression of investigated cytokines in RAO horses on pasture did not differ from controls. In compari...
Fu ZF, Robinson AJ, Horner GW, Dickinson LG, Grimmett JB, Marshall RB.The epizootiology of equine herpesvirus type 2 (EHV-2) infection was investigated in Thoroughbred foals on a stud farm which in previous years had suffered economic loss due to respiratory disease. Sixteen pairs of foals and their dams were selected for this study and all of the foals became infected with EHV-2 by two to four months of age. These animals responded serologically to the virus infection as detected by an enzyme-linked immunosorbent assay (ELISA). EHV-2 infection persisted in these foals for two to six months with constant or intermittent virus recovery. This persistent infection ...
Dixon PM, Froydenlund T, Luiti T, Kane-Smyth J, Horbal A, Reardon RJ.Empyema of the nasal conchal bullae has recently been identified in horses suffering from chronic unilateral nasal discharge. The diagnosis and management of such cases has not been reported previously. Objective: To describe the diagnosis and treatment of cases suffering from empyema of the nasal conchal bullae and report the frequency of diagnosis from a population of horses referred for head computed tomography (CT). Methods: Retrospective case review. Methods: Records from cases diagnosed with nasal conchal bulla disease using CT were reviewed. Results: Abnormalities of the nasal conchal b...
Carvallo FR, Uzal FA, Diab SS, Hill AE, Arthur RM.Respiratory diseases have a major impact on racehorses in training and are often cited as the second most common reason of horses failing to perform. Cases were submitted by the California Horse Racing Board to the California Animal Health and Food Safety laboratory for postmortem examination between January 1, 2005 and December 31, 2014. We determined the demographics of racehorses with fatal pneumonia, characterized the pathologic findings in animals with a postmortem diagnosis of respiratory infection, and determined the most significant pathogens associated with lower respiratory tract dis...
Bountouri M, Fragkiadaki E, Ntafis V, Kanellos T, Xylouri E.For first time in Greece equine influenza virus infection was confirmed, by isolation and molecular analysis, as the cause of clinical respiratory disease among unvaccinated horses during 2003 and 2007 outbreaks. Methods: Equine influenza virus (EIV) H3N8 was isolated in MDCK cells from 30 nasal swabs from horses with acute respiratory disease, which were tested positive by Directigen Flu A. Isolation was confirmed by haemagglutination assay and RT-PCR assay of the M, HA and NA gene. Results: HA sequences of the Greek isolates appeared to be more closely related to viruses isolated in early 19...
McGivney CL, Sweeney J, David F, O'Leary JM, Hill EW, Katz LM.Previous studies support good intra- and interobserver agreements for endoscopic evaluation of various upper respiratory tract (URT) diseases in horses. However, these studies mainly assessed resting endoscopic examination videos and/or focussed on a single URT abnormality. Objective: To estimate intra- and interobserver agreement for identification and grading of all URT abnormalities from resting and overground endoscopy (OGE) videos of Thoroughbreds. Methods: Blinded, fully crossed design. Methods: Resting and OGE URT videos for n = 43 Thoroughbreds were retrospectively chosen based on iden...
Chaffin MK, Cohen ND, Martens RJ.To determine whether foal management practices, environmental management, and preventative health practices are risk factors for 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 for comparison; 1 for an affected farm (containing > or = 1 foal with pneumonia caused by R equi) and 1 for a control farm. Information collected pertained to stabling facilities, environmental management, foal hu...
Yongfeng Y, Xiaobo S, Nan X, Jingwen Z, Wenqiang L.To monitor the occurrence of equine influenza in large-scale donkey farms in Liaocheng City, Shandong Province, serological investigation and sequence analysis of HA/M protein gene of equine influenza virus (EIV) were carried out. Samples (n = 65) of the lung and nasal swab were collected in six different large-scale donkey farms and detected with RT-PCR for HA and M protein gene. The homology and evolution of HA and M genes were analysed with known sequences. Antibody titres of serum samples (n = 120, unvaccinated) level was determined by the HI test. The average seropositive rate was 32....