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.
Pradhan SS, Balena V, Bera BC, Anand T, Khetmalis R, Madhwal A, Kandasamy S, Pavulraj S, Bernela M, Mor P, Tripathi BN, Virmani N.Equine herpesvirus type 1 (EHV1) is a ubiquitous viral pathogen infecting the equine population worldwide. EHV1 infection causes respiratory illness, abortion, neonatal foal mortality, and myeloencephalopathy. The currently available modified live EHV1 vaccines have safety and efficacy limitations. The two mutant EHV1 viruses (vToH-DMV (∆IR6/gE) and vToH-QMV (∆IR6/UL43/gE/UL56)), generated by the deletion of genes responsible for virulence (gE and IR6) and immunosuppression (uL43 and uL56), have been previously characterized by our group and found to generate good immune responses. The pre...
Talbot AM, Shanks-Boon H, Baldwin CM, Barnes H, Maddox TW.Obesity has been associated with human obstructive sleep apnoea and canine brachycephalic obstructive airway syndrome. The effect of body condition score (BCS) on structures of the oropharynx, nasopharynx and upper airway of the horse has not been investigated. Objective: To investigate the effect of BCS on tongue measurements, soft palate angle and basihyoid depth in horses. Methods: Retrospective, analytical, cross-sectional. Methods: Computed tomographic (CT) images of the head of 58 horses were assessed. DICOM viewing software was used to measure head length, basihyoid-skin depth, soft pal...
Charbonnel A, Lavoie JP, Juette T, St-Sauveur VG, Denis S, Gagnon CA, Leclère M.The control of equine respiratory infections is a biosecurity challenge. Respiratory viruses are often rapidly detected using quantitative polymerase chain reaction (qPCR) on nasal swabs. In the past, some laboratories developed handmade techniques to increase the amount of nasal secretions collected, without comparing them with nasal swabs when qPCR replaced the use of viral culture. The objectives of this study were to compare nasal swabs and handmade foam cubes for i) the detection of a common equine herpesvirus (EHV-5) by qPCR, and ii) their tolerability. Forty-five polyester swabs and foa...
Ekinci G, Deniz O, Tüfekci E, Timur MC, Onmaz AC, Günes V, Citil M, Keles I, Hoven RVD.Rhodococcus equi (R. equi) is a primary cause of pyogranulomatous pneumonia of foals between three weeks and five months of age. Early diagnosis of rhodococcal pneumonia has always been considered a preferable approach as it can lead to more successful treatment and better outcomes. Horse stud farms where the disease is common, neonatal foals are subjected to tests such as complete blood count and fibrinogen analysis at certain intervals. However, new biomarkers are needed in addition to blood count and fibrinogen measurement in this field for early diagnosis of diseases. Based on this need, i...
The aim of this study was to evaluate the effects of two styles of classical music, based on different tempos (BPM), on the physiological and blood parameters of horses during social isolation and restriction of movements. First experiment was carried out using nine horses of no defined breed, distributed in Control, Slow-tempo music and Moderate-tempo music .For social isolation and restriction of movement, the animals were housed daily in individual stalls for two hours and exposed to the stimuli for 60 min, and eye temperature, heart rate, and respiratory rate were assessed. The second exp...
Frippiat T, van den Wollenberg L, van Erck-Westergren E, van Maanen K, Votion DM.Some respiratory viruses can affect equine athletes, with acute respiratory clinical signs leading to a reduced ability to perform. The direct association between equine respiratory viruses and athletic performance is unclear in subclinically affected horses. This narrative review summarises the current evidence on respiratory viruses most commonly detected in performing horses, including equine herpesviruses, equine influenza virus, equine rhinitis viruses, equine arteritis virus, and equine adenovirus 1. It covers their virology, clinical manifestations, epidemiology, pathogenesis, diagnosis...
Rossi HS, Hyytiäinen HK, Junnila JJT, Rajamäki MM, Mykkänen AK.Pneumonia is a common condition in ailing neonatal foals, and it remains an important cause of morbidity and mortality in this veterinary patient group. Factors affecting the survival of young foals with pneumonia have not been thoroughly investigated. The aim of this study was to explore the potential prognostic factors associated with survival of these foals. Fifty foals under one month of age with pneumonia were included in this retrospective clinical study. The foals were divided into groups based on survival (survived to discharge or died/euthanised during hospitalisation). Multiple clini...
Bishop RC, Nobrega AD, Mersich I, Wilkins PA.To describe indications for and demonstrate the technique to perform a transtracheal aspirate in horses. Transtracheal aspirate is indicated to collect samples for cytology and bacteriologic culture in cases of suspected pneumonia or other lower respiratory tract disease. Methods: 1 healthy university-owned horse was used for demonstration purposes. Images of clinical case samples from the University of Illinois Veterinary Teaching Hospital are shown. Methods: The horse is restrained and sedated with detomidine or xylazine to facilitate restraint and butorphanol to minimize coughing. The ventr...
Brandenberger O, Kalinovskiy A, Körner J, Genn H, Burger R, Leser S.The use of Bio-Electro-Magnetic-Energy-Regulation (BEMER) therapy during general anesthesia has not previously been reported in horses. This randomized, investigator-blinded, placebo-controlled trial evaluates equine cardiopulmonary function and recovery quality after BEMER therapy application for 15 min in 100 horses during general anesthesia using isoflurane for pars-plana vitrectomy surgery as treatment for recurrent uveitis. Visually identical blankets were used in the two groups (1:1 ratio), one with a functional BEMER module and the other with a placebo module. Arterial blood pressure, b...
Hordle T, Ranninger E, Bettschart-Wolfensberger R.A 24 year old warmblood mare (case 1) and a 12 year old Holsteiner gelding (case 2) were anaesthetized for bursoscopy and phacoemulsification, respectively. Both were premedicated with intramuscular acepromazine (30 μg kg-1). The horses were sedated with intravenous (IV) medetomidine (7-9 μg kg-1 to effect), before anaesthetic induction with ketamine-diazepam. Anaesthesia was maintained with isoflurane in a mixture of oxygen and medical air, alongside a medetomidine constant rate infusion at 3.5 μg kg-1 hour-1. In recovery, 3 and 5 μg kg-1 of medetomidine were administered IV to cases 1 an...
Egli P, Boone L, Huber L, Higgins C, Gaonkar PP, Arrington J, Naskou MC, Peroni J, Gordon J, Lascola KM.Platelet lysate (PL) demonstrates antimicrobial and anti-inflammatory properties offering potential for treatment of bacterial pneumonia in horses. It remains unknown whether nebulization is suitable for PL administration in horses. This pilot study characterized particle size and flow rate of pooled equine PL (single preparation) nebulized using an equine-specific nebulizer (Flexivent®). Unassigned: Protein composition and antimicrobial activity were compared before and after nebulization. Protein composition was evaluated according to growth factor, antimicrobial peptide and cytokine concen...
Magdesian KG.Knowledge of immunodeficiencies is crucial to neonatal medicine, in that they predispose to sepsis in the newborn and neonatal foal, as well as recurrent infections in older foals. The most common immunodeficiency in newborn and neonatal foals is failure of passive transfer, which is an example of an acquired immunodeficiency. Congenital or developmental immunodeficiencies may be transient or permanent, and can either affect the cell-mediated or humoral arms of immunity, and in some cases both. Affected foals often have chronic or recurrent respiratory or gastrointestinal infections, often wit...
Cervantes-Sevilla JR, Ramírez-Cervera M, Guzman-Ruvalcaba MJ.Traumatic hemothorax is a serious condition requiring immediate intervention. We present a case of a 48-year-old male professional jockey who suffered traumatic hemothorax, bilateral pulmonary contusions, and multiple rib fractures after being stomped by a horse. Management included intercostal drainage placement, costal fixation from the 5th to the 10th rib, and intensive care unit admission. Postoperative complications included, acute kidney injury, rhabdomyolysis, and severe acute respiratory distress syndrome. This case highlights the importance of a multidisciplinary approach in managing ...
Padalino B, Pellegrini F, Felici M, Zappaterra M, Catella C, Cordisco M, Lorusso E, Cirone F, Pratelli A.Respiratory disorders (RDs) are a common transport-related welfare consequence in horses. This prospective study described the journeys of horses transported to two slaughterhouses in Italy, documented the prevalence of potentially RD-related pathogens, and identified possible predisposing factors. Data were recorded from arrival until 48 h after arrival and included the collection of Deep Nasopharyngeal Swabs (DNS), journey details and welfare assessment of horses (n = 155). PCR was used to quantify the presence of influenza A virus, reovirus, equine herpesvirus type 1 and 4, adenovirus, r...
Equine asthma, a prevalent chronic inflammatory condition affecting the equine population, significantly compromises the performance and quality of life in affected horses. Inhaled corticosteroids (ICS) are often the first-line pharmacological intervention due to their potent anti-inflammatory properties. This meta-analysis investigates the clinical efficacy of ICS in treating equine asthma, emphasizing the number needed to treat (NNT) and the likelihood of achieving a clinical response. A comprehensive literature search identified relevant studies comparing ICS with placebo (PCB) controlled t...
Lendl L, Barton AK.This literature review focuses on diagnostics of equine asthma (EA), possible influencing factors on diagnostic techniques and latest developments in diagnosing horses during EA remission or with subclinical disease. Routine EA diagnostics include a clinical examination of the respiratory system with percussion and auscultation including a rebreathing examination, and clinical pathology including white blood cells and arterial blood gas analysis. Subsequent diagnostics include bronchoscopy to evaluate the amount and viscosity of respiratory secretion, bronchoalveolar lavage, and the cytology o...
Mau A, Keller SM, Kol A.Basophils are the rarest blood leukocyte in most healthy domestic mammals and the clinical significance of basophilia is poorly understood. Objective: To empirically determine magnitude thresholds for basophilia, identify its hematologic correlates, and identify associations between breeds, specific diseases, disease categories, organ systems, and basophilia in dogs, cats, and horses. Methods: CBCs and clinical information from dogs, cats, and horses were collected from the University of California-Davis School of Veterinary Medicine between 2000 and 2020. Relationships between basophil concen...
Chhabra D, Nagra J, Manuja A, Singha HS, Vaid RK, Goutam U, Kumar B. poses a significant threat to equine health globally. The bacteria causes strangles, a respiratory disease characterized by enlarged, abscessed lymph nodes, leading to airway obstruction. The bacterium, a Gram-positive, chain-forming, Lancefield group C β-hemolytic , is closely related to and distinction between these species is challenging. The present study focused on characterization of isolates from horses in northern India, aiming at elucidation of their sugar fermentation patterns. Nasal and nasopharyngeal swabs collected from different geographical regions of northern India, yieldin...
de Lima AE, Mendes RP, Piñeros DDV, Alibrando BB, de Zoppa ALV, da Silva LCLC, de Freitas SH, Corrêa RR.Sinusitis is common in horses. Sinoscopy is used for visualization of sinus cavities and can be used for diagnostic and therapeutic purposes. In this surgical procedure, a larger chamber is created and communication with other sinus compartments facilitated. To compare the applicability of different surgical approaches and rigid endoscopy systems for sinus inspection and fenestration of the maxillary septal bulla, and to examine the impact of different lens angles on the effectiveness of the procedure. Six chemically preserved cadaveric equine heads were used. Frontal and caudal maxillary port...
Brito PHS, Ferreira MA, Rusch E, Arantes JA, Carregaro AB, Valadão CAA, Ghantous GF, Dória RGS.Submitting late-term pregnant mares to anesthesia for non-obstetric surgery raises concerns about the survival of the mother and fetus. This study aimed to evaluate and describe transient maternal and fetal hemodynamic changes during general inhalation anesthesia in mares during the last month of gestation. Nine adult mares in the last month of gestation were subjected to general inhalation anesthesia and dorsal recumbency for 90 minutes. Trans-anesthetic vital parameters, arterial hemogasometry, cardiac output, pulmonary arterial pressure, central venous pressure, and fetal heart rates were a...
Mazzei M, Sorvillo B, Sgorbini M, Bindi F, Perelli A, Laus F.(1) Background: Respiratory problems may be associated with pathogens among which viruses may play an important role in causing or promoting clinical signs. However, traditional diagnostic methods for equine infectious diseases, such as PCR, are limited to known pathogens and often miss rare or novel viruses. Metagenomic next-generation sequencing is a transformative method that allows the sequencing of all genomes present in a sample. Recent studies have used next-generation sequences to identify viral sequences in horses with unexplained respiratory symptoms, revealing potential links betwee...
Mazzei M, Sorvillo B, Sgorbini M, Bindi F, Perelli A, Laus F.(1) Background: Respiratory problems may be associated with pathogens among which viruses may play an important role in causing or promoting clinical signs. However, traditional diagnostic methods for equine infectious diseases, such as PCR, are limited to known pathogens and often miss rare or novel viruses. Metagenomic next-generation sequencing is a transformative method that allows the sequencing of all genomes present in a sample. Recent studies have used next-generation sequences to identify viral sequences in horses with unexplained respiratory symptoms, revealing potential links betwee...
Norton AM, Rosanowski SM, O'Brien T.Epiglottic entrapment (EE) is a common cause of poor performance in racing standardbreds (STBs) and thoroughbreds (TBs). There is limited information published on the condition in STB racehorses and limited information on factors associated with return to racing available for either breed. Unassigned: This study investigated and compared the pre surgical findings, post-surgical complications and racing performance in STBs and TBs undergoing surgery for correction of EE. Associations between signalment and pre-surgical findings, and the presence of complications and racing post-surgery were com...
Mainguy-Seers S, Holcombe SJ, Lavoie JP.Vitamin D deficiency is associated with asthma development and severity of symptoms in humans, but whether the same occurs in horses is unknown. We aimed to determine whether the serum vitamin D levels differ in horses with asthma compared to control animals and, secondarily, to explore clinical, respiratory, and environmental parameters associated with its concentration in equids in a retrospective cross-sectional study. The total serum vitamin D (25(OH)D) was measured by radioimmunoassay in 45 serum samples from the Equine Respiratory Tissue Biobank (15 control animals, 14 horses with mild o...
Li S, Li L, Sun Y, Khan MZ, Yu Y, Ruan L, Chen L, Zhao J, Jia J, Li Y, Wang C, Wang T.Equid herpesvirus type 8 (EqHV-8) is known to cause respiratory disease and miscarriage in horses and donkeys, which is a major problem for the equine farming industry. However, there are currently limited vaccines or drugs available to effectively treat EqHV-8 infection. Therefore, it is crucial to develop new antiviral approaches to prevent potential pandemics caused by EqHV-8. This study evaluates the antiviral and antioxidant effects of cepharanthine against EqHV-8 by employing both in vitro assays and in vivo mouse models to assess its therapeutic efficacy. To assess the effectiveness of ...
Bozzola C, Sala G, Schinardi L, Stancari G, Stucchi L, Ferrucci F, Zucca E.Exercise-Induced Pulmonary Hemorrhage (EIPH) is a common pulmonary disease among racehorses, diagnosed by the detection of blood in the trachea after strenuous exercise or the presence of hemosiderophages in the bronchoalveolar lavage fluid (BALF). Although the latter is considered the most sensitive method to diagnose EIPH, it is perceived as a less practical and more invasive procedure compared to tracheal wash (TW) collection among racehorse trainers. The present retrospective study aimed to verify the agreement between Tracheal wash and BALF cytology in assessing EIPH in racehorses. For th...
Nomura M, Kuroda T, Ohta M, Kusano K, Minamijima Y, Nagata S.Salbutamol is a short-acting and selective beta-2 adrenergic agonist. Inhaled (IH) administration of salbutamol is widely used to control lower respiratory tract disease in horses. Here, we estimated the pharmacokinetic parameters of salbutamol after a single intravenous (IV) or IH administration in six horses, and we statistically analysed the detection times with various dosing regimens. Plasma and urine concentrations of salbutamol were measured by liquid chromatography-tandem mass spectrometry, and data were modelled by using a nonlinear mixed effect model followed by Monte Carlo simulatio...
Massie S, Léguillette R, Bayly W, Sides R, Zuluaga-Cabrera AM.Workload associated with the high frequency Colombian Paso Fino gait has not been evaluated. Objective: To determine the oxygen consumption (V̇O), heart rate (HR), stride frequency: breathing ratio, and hematology associated with the Paso Fino gait, including whether exercise-induced pulmonary hemorrhage (EIPH) occurs. Methods: Eleven Paso Fino horses. Methods: Prospective cohort study. Horses performed a standardized Paso Fino gait test across a wooden sounding board, simulating competition. V̇O and ventilatory parameters (tidal volume [V]; peak inspiratory and expiratory airflows [PkV̇, P...
Ivester KM, Ni JQ, Couetil LL, Peters TM, Tatum M, Willems L, Park JH.Affordable particulate matter (PM) monitors suitable for use on horses will facilitate the evaluation of PM mitigation methods and improve the management of equine asthma. Objective: Calibrate a real-time wearable PM monitor (Black Beauty [BB]) and compare the PM exposures of horses fed dry or soaked hay. Methods: Laboratory calibration; complete cross-over feed trial. Methods: Side-by-side sampling with BB monitors and tapered element oscillating microbalances (TEOMs) was performed under varying concentrations of PM from alfalfa hay. Linear regression was used to derive a calibration formula ...
Respirable mineral particles can induce lower airway inflammation, but the role they play in asthma of horses is unknown. Objective: Respirable mineral particles, particularly respirable silica, are an overlooked determinant of chronic lung inflammation (asthma) in horses. Methods: Twenty-three horses from an equine hospital population: 11 moderately affected (MEA), 7 severely asthmatic (SEA), and 5 control horses free from respiratory clinical signs. Methods: Prospective observational study. The quantity and quality of mineral particles found in bronchoalveolar lavage fluid (BALF) were charac...
Fillion-Bertrand G, Dickson RP, Boivin R, Lavoie JP, Huffnagle GB, Leclere M.There is evidence that the lung microbiome differs between patients with asthma and healthy humans, but the effect of environmental conditions and medication is unknown and difficult to study. Equine asthma is a naturally occurring chronic airway disease characterized by reversible airway inflammation and bronchoconstriction upon exposure to inhaled antigens. In the present study, we evaluated the effect that environmental conditions and disease status have on pulmonary, nasal, and oral microbiomes. Six asthmatic and six healthy horses were studied while at pasture ("low antigen exposure"), as...
Laumen E, Doherr MG, Gerber V.The horse owner assessed respiratory signs index (HOARSI-1-4, healthy, mildly, moderately and severely affected, respectively) is based on owner-reported clinical history and has been used for the investigation of recurrent airway obstruction (RAO) genetics utilising large sample sizes. Reliable phenotype identification is of paramount importance in genetic studies. Owner reports of respiratory signs have shown good repeatability, but the agreement of HOARSI with an in-depth examination of the lower respiratory tract has not been investigated. Objective: To determine the correlation of HOARSI ...
Huber L, Giguère S, Slovis NM, Carter CN, Barr BS, Cohen ND, Elam J, Erol E, Locke SJ, Phillips ED, Smith JL.The objective of this study was to determine the prevalence of strains resistant to macrolides and rifampin over time in clinical samples from foals submitted to diagnostic laboratories in central Kentucky. We performed a retrospective observational study of all clinical samples from foals that were submitted to veterinary diagnostic laboratories in Kentucky between January 1995 and December 2017. Samples were included if the bacterium was cultured and tested for susceptibility to erythromycin or rifampin. susceptibility testing to erythromycin was available for 2,169 isolates of , while s...
Koblinger K, Nicol J, McDonald K, Wasko A, Logie N, Weiss M, Léguillette R.Comprehensive endoscopic scoring of the upper and lower airways for inflammation has not been critically assessed among a large population of horses. The relationship between upper and lower airways described in humans by the "one airway, one disease" concept might also apply to horses. Objective: To evaluate if an association exists between endoscopic inflammatory scores and mucus scores of upper and lower airways and to investigate if endoscopic findings correlate with the lower airway inflammation measured by bronchoalveolar lavage (BAL) cytology. Methods: Prospective field study. Pharyngit...
Zhang M, Li X, Deng Z, Chen Z, Liu Y, Gao Y, Wu W, Chen Z.Endoribonuclease (NendoU) is unique and conserved as a major genetic marker in nidoviruses that infect vertebrate hosts. Arterivirus nonstructural protein 11 (nsp11) was shown to have NendoU activity and play essential roles in the viral life cycle. Here, we report three crystal structures of porcine reproductive and respiratory syndrome virus (PRRSV) and equine arteritis virus (EAV) nsp11 mutants. The structures of arterivirus nsp11 contain two conserved compact domains: the N-terminal domain (NTD) and C-terminal domain (CTD). The structures of PRRSV and EAV endoribonucleases are similar and ...
Reznik GK.The anatomical characteristics of the upper respiratory tract of various experimental animals and man are described. There are a number of differences and similarities macroscopically and microscopically between the species. Perhaps one of the most obvious examples of anatomical differences is in the structure of the turbinates. Some of the differences could affect deposition and clearance of particles in the nasal cavities. Effects of compounds in the nasal cavity, larynx, and trachea can differ depending on the cellular composition of the mucosa.
Samadi S, Wouters IM, Houben R, Jamshidifard AR, Van Eerdenburg F, Heederik DJ.Workers in horse stables are likely exposed to high levels of organic dust. Organic dusts play a role in increased risk of inflammatory reactions and are associated with respiratory diseases. The aim of this study was to investigate dust, endotoxin, beta(1-->3)-glucan, and culturable microorganisms exposure levels in horse stables. Methods: Ambient (n = 38) and personal (n = 42) inhalable dust samples were collected using PAS-6 sampling heads. As a special measurement, we included sampling near the horses' heads. Samples were analyzed for endotoxin and beta(1-->3)-glucan by Limulus amebo...
Perkins NR, Reid SW, Morris RS.To describe and enumerate conditions that interrupted training and racing in a population of Thoroughbred racehorses in New Zealand. Methods: A longitudinal study design was used to collect data on horses training under the care of 20 licensed racehorse trainers from venues in the mid to lower regions of the North Island between October 1997 and July 2000. Incidence rates were reported for first and second occurrences for different categories of musculoskeletal injury (MSI), and first occurrences of upper and lower respiratory tract disease, using training days as time-at-risk. The proportion ...
Quintana AM, Landolt GA, Annis KM, Hussey GS.Our understanding of innate immunity within the equine respiratory tract is limited despite growing evidence for its key role in both the immediate defense and the shaping of downstream adaptive immune responses to respiratory disease. As the first interface to undergo pathogen invasion, the respiratory epithelium is a key player in these early events and our goal was to examine the innate immune characteristics of equine respiratory epithelia and compare them to an in vitro equine respiratory epithelial cell model cultured at the air-fluid interface (AFI). Respiratory epithelial tissues, isol...
McGorum BC, Ellison J, Cullen RT.The concentrations of total and respirable airborne endotoxin in the breathing zone of a pony in 3 different management systems, on 8 occasions, are reported. Airborne endotoxin concentrations in all 3 systems were lower than those reported for many other agricultural environments. However, total airborne endotoxin concentrations in many of the conventional stables exceeded those which can induce pulmonary inflammation and bronchial hyper-responsiveness in normal human subjects, and exceeded those which can induce bronchoconstriction in humans with pre-existing pulmonary inflammation. Therefor...
Adney DR, Brown VR, Porter SM, Bielefeldt-Ohmann H, Hartwig AE, Bowen RA.The Middle East respiratory syndrome coronavirus (MERS-CoV) was first recognized in 2012 and can cause severe disease in infected humans. Dromedary camels are the reservoir for the virus, although, other than nasal discharge, these animals do not display any overt clinical disease. Data from in vitro experiments suggest that other livestock such as sheep, goats, and horses might also contribute to viral transmission, although field data has not identified any seropositive animals. In order to understand if these animals could be infected, we challenged young goats and horses and adult sheep wi...
Couëtil LL, Denicola DB.The purpose of this study was to evaluate the relationship between bronchoalveolar lavage (BAL) cytology, arterial blood gases and plasma lactate concentration during a standardised treadmill test (STT) in racehorses with small-airway inflammation (SAI), or exercise-induced pulmonary haemorrhage (EIPH). Sixteen Thoroughbred and 20 Standardbred actively racing racehorses, were divided into a control group (n = 10), EIPH group (n = 13) and SAI group (n = 13). Each STT consisted of a 2 min trot at 4 m/s followed by 5 x 1 min, incremental speed steps (6, 8, 10, 11 and 12 m/s) at 10% incline for Th...
Dauvillier J, Ter Woort F, van Erck-Westergren E.Fungi contribute to the inflammatory response of lungs in horses with recurrent airway obstruction and in some forms of asthma in humans. The role of fungi in inflammatory airway disease (IAD) has not been assessed. Objective: Evaluate the prevalence of fungi in the respiratory samples of horses diagnosed with IAD, describe clinical signs associated with the presence of fungi in respiratory samples, and assess the risk factors associated with IAD and with the presence of fungi in the airways. Methods: Seven-hundred thirty-one active horses referred to a specialized ambulatory practice for sign...
Gerber V, Baleri D, Klukowska-Rötzler J, Swinburne JE, Dolf G.Mode of inheritance of equine recurrent airway obstruction (RAO) is unknown. Objective: Major genes are responsible for RAO. Methods: Direct offspring of 2 RAO-affected Warmblood stallions (n = 197; n = 163) and a representative sample of Swiss Warmbloods (n = 401). Methods: One environmental and 4 genetic models (general, mixed inheritance, major gene, and polygene) were tested for Horse Owner Assessed Respiratory Signs Index (1-4, unaffected to severely affected) by segregation analyses of the 2 half-sib sire families, both combined and separately, using prevalences estimated in a representa...
Pacholewska A, Kraft MF, Gerber V, Jagannathan V.MicroRNAs (miRNAs) regulate post-transcriptional gene expression and may be exported from cells via exosomes or in partnership with RNA-binding proteins. MiRNAs in body fluids can act in a hormone-like manner and play important roles in disease initiation and progression. Hence, miRNAs are promising candidates as biomarkers. To identify serum miRNA biomarkers in the equine model of asthma we investigated small RNA derived from the serum of 34 control and 37 asthmatic horses. These samples were used for next generation sequencing, novel miRNA identification and differential miRNA expression ana...
Diaz-Mendez A, Viel L, Hewson J, Doig P, Carman S, Chambers T, Tiwari A, Dewey C.The objective of this project was to develop and implement an active surveillance program for the early and rapid detection of equine influenza viruses in Ontario. For this purpose, from October 2003 to October 2005, nasopharyngeal swabs and acute and convalescent serum samples were collected from 115 client-owned horses in 23 outbreaks of respiratory disease in Ontario. Sera were paired and tested for antibody to equine influenza 1 (AE1-H7N7), equine influenza 2 (AE2-H3N8), equine herpesvirus 1 and 4 (EHV1 and EHV4), and equine rhinitis A and B (ERAV and ERBV). Overall, the cause-specific mor...
Wada R, Kamada M, Anzai T, Nakanishi A, Kanemaru T, Takai S, Tsubaki S.Twelve foals, between 27 and 83 days old, were infected with 2 strains of Rhodococcus equi by intratracheal administration. Ten of the 12 foals were inoculated with 10(4)-10(10) colony forming units (cfu) of ATCC 33701 strain. The other 2 foals were inoculated with 10(9) cfu of a plasmid-cured derivative of the ATCC 33701 strain (ATCC 33701P-). All of the 10 foals challenged with the ATCC 33701 strain showed clinical signs of pulmonary disease within 5-13 days, such as gross lesions associated with acute bronchopneumonia and microscopic lesions associated with granulomatous pneumonia. The two ...
Bureau F, Bonizzi G, Kirschvink N, Delhalle S, Desmecht D, Merville MP, Bours V, Lekeux P.Asthma is a chronic inflammatory disease of the airways, in which many inflammatory genes are overexpressed. Transcription factor, nuclear factor-kappaB (NF-kappaB), which is thought to control the transcriptional initiation of inflammatory genes, has been poorly investigated in asthma. In the present report, bronchial cells (BCs), recovered by bronchial brushing in healthy and heaves-affected horses (i.e., an animal model of asthma), were assessed for NF-kappaB activity. Small amounts of active NF-kappaB were present in BCs of healthy horses, whereas high levels of NF-kappaB activity was foun...
Hines SA, Stone DM, Hines MT, Alperin DC, Knowles DP, Norton LK, Hamilton MJ, Davis WC, McGuire TC.Rhodococcus equi is a gram-positive bacterium that infects alveolar macrophages and causes rhodococcal pneumonia in horses and humans. The virulence plasmid of R. equi appears to be required for both pathogenicity in the horse and the induction of protective immunity. An understanding of the mechanisms by which virulent R. equi circumvents protective host responses and by which bacteria are ultimately cleared is important for development of an effective vaccine. Six adult horses were challenged with either virulent R. equi or an avirulent, plasmid-cured derivative. By using a flow cytometric m...
Flaminio MJ, Rush BR, Davis EG, Hennessy K, Shuman W, Wilkerson MJ.Studies in infants and foals indicate an age-dependent maturation of peripheral lymphocyte subsets. The age-dependent relationship for maturation of cellular immune responses, such as phagocytosis and lymphocyte responses of the peripheral and pulmonary-derived leukocytes, has not been characterized in foals. Lymphocyte subpopulations, mitogen stimulation response of lymphocytes, lymphokine-activated killing cell activity, phagocytosis and oxidative burst activity, and serum immunoglobulin (Ig) classes G and M concentrations were determined in developing foals. This study illustrates age-depen...
Nordengrahn A, Rusvai M, Merza M, Ekström J, Morein B, Belák S.Equine herpesvirus type 2 (EHV-2), a member of the Gammaherpesvirinae subfamily, was studied in a two-phase respiratory disease complex of young foals as a predisposing factor for the secondary bacterial invasion of lungs with Rhodococcus equi (R. equi). Foals were immunized against EHV-2 on a farm where R. equi pneumonia regularly occurred during the last years. The immunizations were performed by using a subunit vaccine which selectively presents envelope glycoproteins of EHV-2 in a multimeric form of immunostimulating complexes (iscoms). The etiological role of EHV-2 was estimated by observ...
Paillot R, Prowse L, Montesso F, Huang CM, Barnes H, Escala J.Equine influenza (EI) is a serious respiratory disease of horses induced by the equine influenza virus (EIV). Surveillance, quarantine procedures and vaccination are widely used to prevent or to contain the disease. This study aimed to further characterise the immune response induced by a non-updated inactivated EI and tetanus vaccine, including protection against a representative EIV isolate of the Florida clade 2 sublineage. Seven ponies were vaccinated twice with Duvaxyn IE-T Plus at an interval of four weeks. Five ponies remained unvaccinated. All ponies were experimentally infected with t...
Heldens JG, Hannant D, Cullinane AA, Prendergast MJ, Mumford JA, Nelly M, Kydd JH, Weststrate MW, van den Hoven R.Pregnant mares and young foals were vaccinated with Duvaxyn EHV1,4, an inactivated and adjuvanted vaccine containing both the EHV-1 and 4 antigens. SN and CF antibody titres were induced two weeks after first vaccination. Antibody levels were boosted after second vaccination, however they never reached the levels induced after virus challenge. Young foals were challenged with virulent EHV-1 and EHV-4 field viruses. Pregnant mares were challenged with the highly abortigenic EHV-1 strain Ab4. Vaccinated animals showed a clear reduction in clinical signs and virus excretion compared to unvaccinat...
Muscatello G, Anderson GA, Gilkerson JR, Browning GF.The ecology of virulent strains of Rhodococcus equi on horse farms is likely to influence the prevalence and severity of R. equi pneumonia in foals. This study examined the association between the ecology of virulent R. equi and the epidemiology of R. equi pneumonia by collecting air and soil samples over two breeding seasons (28 farm-year combinations) on Thoroughbred breeding farms with different reported prevalences of R. equi pneumonia. Colony blotting and DNA hybridization were used to detect and measure concentrations of virulent R. equi. The prevalence of R. equi pneumonia was associate...
Tessier L, Côté O, Clark ME, Viel L, Diaz-Méndez A, Anders S, Bienzle D.Severe equine asthma is a naturally occurring lung inflammatory disease of mature animals characterized by neutrophilic inflammation, bronchoconstriction, mucus hypersecretion and airway remodeling. Exacerbations are triggered by inhalation of dust and microbial components. Affected animals eventually are unable of aerobic performance. In this study transcriptomic differences between asthmatic and non-asthmatic animals in the response of the bronchial epithelium to an inhaled challenge were determined. Results: Paired endobronchial biopsies were obtained pre- and post-challenge from asthmatic ...
Muscatello G.Rhodococcus equi pneumonia is a worldwide infectious disease of major concern to the equine breeding industry. The disease typically manifests in foals as pyogranulomatous bronchopneumonia, resulting in significant morbidity and mortality. Inhalation of aerosolised virulent R. equi from the environment and intracellular replication within alveolar macrophages are essential components of the pathogenesis of R. equi pneumonia in the foal. Recently documented evidence of airborne transmission between foals indicates the potential for an alternative contagious route of disease transmission. In the...
Fernandez NJ, Hecker KG, Gilroy CV, Warren AL, Léguillette R.Reliable enumeration of mast cells and eosinophils in equine bronchoalveolar lavage (BAL) fluid is important because small increases in the percentages of these cells support the clinical diagnosis of inflammatory airway disease (IAD). Increases in BAL neutrophils also occur with IAD but are not specific due to overlap between IAD and recurrent airway obstruction (RAO). Objective: The objectives of this study were to evaluate the reliability of a standard 400-cell leukocyte differential count and an alternate method evaluating 5 microscopic fields at 500× magnification in equine BAL fluid cyt...
Cohen ND.Pneumonia caused by Rhodococcus equi is an important cause of disease and death in foals. This article reviews current knowledge of the epidemiology, clinical signs, diagnosis, treatment, prevention, and control of R equi pneumonia in foals.
Williams KJ.Progressive lung fibrosis in humans, typified by idiopathic pulmonary fibrosis (IPF), is a serious cause of morbidity and mortality in people. Similar diseases have been described in dogs, cats, and horses. The cause and pathogenesis of such diseases in all species is poorly understood. There is growing evidence in human medicine that IPF is a manifestation of abnormal wound repair in response to epithelial injury. Because viruses can contribute to epithelial injury, there is increasing interest in a possible role of viruses, particularly gammaherpesviruses, in the pathogenesis of pulmonary fi...
Giguère S, Jacks S, Roberts GD, Hernandez J, Long MT, Ellis C.The objective of this retrospective study was to compare the efficacy of azithromycin-rifampin, clarithromycin-rifampin, and erythromycin-rifampin for the treatment of pneumonia caused by Rhodococcus equi in foals. Eighty-one foals with naturally acquired pneumonia caused by R. equi were included in the study. Information on age, sex, breed, physical examination findings, laboratory testing, and thoracic radiography was abstracted from each medical record. Foals were divided in 3 groups based on the antimicrobial agent selected for therapy. Short-term (discharge from the hospital) and long-ter...
