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.
Bond SL, Hundt J, Léguillette R.Mild equine asthma is a common inflammatory airway disease of the horse. The primary treatment of mild equine asthma is corticosteroids. The purpose of this study was to investigate the effects of injected dexamethasone on relative IL-1β, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p35, IL-17, IL-23, IFN-γ, Eotaxin-2 and TNF-α mRNA expression in bronchoalveolar lavage (BAL) fluid in healthy Thoroughbred horses (n = 6), and those with mild equine asthma (n = 7). Results: Horses with mild equine asthma had a significantly greater bronchoalveolar lavage mast cell percentage than healthy horses...
Oladunni FS, Reedy S, Balasuriya UBR, Horohov DW, Chambers TM.Equine herpesvirus type 4 (EHV-4) is mildly pathogenic but is a common cause of respiratory disease in horses worldwide. We previously demonstrated that unlike EHV-1, EHV-4 is not a potent inducer of type-I IFN and does not suppress that IFN response, especially during late infection, when compared to EHV-1 infection in equine endothelial cells (EECs). Here, we investigated the impact of EHV-4 infection in EECs on type-I IFN signaling molecules at 3, 6, and 12 hpi. Findings from our study revealed that EHV-4 did not induce nor suppress TLR3 and TLR4 expression in EECs at all the studied time...
Pozzoli C, Bertini S, Poli E, Placenza G, Menozzi A.β-adrenoceptor agonists are considered the most effective drugs to counteract bronchoconstriction in horses with asthma, but only clenbuterol is commonly employed in clinical practice. We evaluated the effects of different selective β agonists: clenbuterol, ritodrine, salbutamol, and fenoterol on the contractions of isolated bronchial muscle of horses induced by electrical field stimulation (EFS), carbachol, histamine, and KCl. All β agonists reduced the amplitude of contraction induced by the different stimuli but with variable efficacy and potency. Fenoterol and salbutamol were more effec...
Fretheim-Kelly ZL, Halvorsen T, Clemm H, Roksund O, Heimdal JH, Vollsæter M, Fintl C, Strand E.Dynamic obstructions of the larynx are a set of disorders that occur during exercise in equines and humans. There are a number of similarities in presentation, diagnosis, pathophysiology and treatment. Both equines and humans present with exercise intolerance secondary to dyspnea. During laryngoscopy at rest, the larynx appears to function normally. Abnormalities are only revealed during laryngoscopy at exercise, seemingly triggered by increased ventilatory demands, and quickly resolve after cessation of exercise. Lower airway disease (asthma being the most prevalent condition), cardiac diseas...
Cercone M, Olsen E, Perkins JD, Cheetham J, Mitchell LM, Ducharme NG.Exercise induced intermittent dorsal displacement of the soft palate (DDSP) is a common cause of airway obstruction and poor performance in racehorses. The definite etiology is still unclear, but through an experimental model, a role in the development of this condition was identified in the dysfunction of the thyro-hyoid muscles. The present study aimed to elucidate the nature of this dysfunction by investigating the spontaneous response to exercise of the thyro-hyoid muscles in racehorses with naturally occurring DDSP. Intramuscular electrodes were implanted in the thyro-hyoid muscles of nin...
White SJ, Moore-Colyer M, Marti E, Hannant D, Gerber V, Coüetil L, Richard EA, Alcocer M.Severe equine asthma (sEA), which closely resembles human asthma, is a debilitating and performance-limiting allergic respiratory disorder which affects 14% of horses in the Northern Hemisphere and is associated with increased allergen-specific immunoglobulin E (IgE) against a range of environmental proteins. A comprehensive microarray platform was developed to enable the simultaneous detection of allergen-specific equine IgE in serum against a wide range of putative allergenic proteins. The microarray revealed a plethora of novel pollen, bacteria, mould and arthropod proteins significant in t...
Back H, Weld J, Walsh C, Cullinane A.The aim of this study was to identify respiratory viruses circulating amongst elite racehorses in a training yard by serological testing of serial samples and to determine their impact on health status and ability to race. A six-month longitudinal study was conducted in 30 Thoroughbred racehorses (21 two-year-olds, five three-year-olds and four four-year-olds) during the Flat racing season. Sera were tested for the presence of antibodies against equine herpesvirus 1 and 4 (EHV-1 and EHV-4) and equine rhinitis viruses A and B (ERAV and ERBV) by complement fixation (CF) and equine arteritis viru...
Altan E, Li Y, Sabino-Santos G, Sawaswong V, Barnum S, Pusterla N, Deng X, Delwart E.Metagenomics was used to identify viral sequences in the plasma and CSF (cerobrospinal fluid) of 13 horses with unexplained neurological signs and in the plasma and respiratory swabs of 14 horses with unexplained respiratory signs. Equine hepacivirus and two copiparvoviruses (horse parvovirus-CSF and a novel parvovirus) were detected in plasma from neurological cases. Plasma from horses with respiratory signs contained the same two copiparvoviruses plus equine pegivirus D and respiratory swabs contained equine herpes virus 2 and 5. Based on genetic distances the novel copiparvovirus qualified ...
Jones S, Franklin S, Martin C, Steel C.There is limited knowledge of the breathing strategy and impact on the patency of the upper respiratory tract (URT) in swimming horses. Objective: To describe the respiratory responses and endoscopic appearance of the URT during tethered swimming in horses. Methods: Prospective descriptive study. Methods: Ten race-fit horses, with no history of URT obstruction, were examined during tethered swimming. Endoscopic examination, heart rate, sound recordings and above and below water video recordings were obtained. Plasma lactate concentration was measured before and 5 min after swimming and trache...
Sutton G, Garvey M, Cullinane A, Jourdan M, Fortier C, Moreau P, Foursin M, Gryspeerdt A, Maisonnier V, Marcillaud-Pitel C, Legrand L, Paillot R....Equine herpesvirus 1 (EHV-1) is an Alphaherpesvirus infecting not only horses but also other equid and non-equid mammals. It can cause respiratory distress, stillbirth and neonatal death, abortion, and neurological disease. The different forms of disease induced by EHV-1 infection can have dramatic consequences on the equine industry, and thus the virus represents a great challenge for the equine and scientific community. This report describes the progress of a major EHV-1 outbreak that took place in Normandy in 2009, during which the three forms of disease were observed. A collection of EHV-1...
Rickards KJ, Thiemann AK.Donkeys suffer from the same respiratory diseases as horses; however, owing to their nonathletic nature many conditions can present in a more advanced state before becoming clinically apparent. Anatomically, their respiratory tract is similar to the horse, with certain species-specific differences that are important to be aware of. Often donkeys do not receive the same level of routine care as horses, so many are not vaccinated against respiratory pathogens such as influenza or herpesviruses. Donkeys can act as a reservoir for certain infectious and parasitic respiratory diseases and the inter...
Legere RM, Wooldridge AA, Sandey M, Hanson RR, Cole R.This case represents the first reported case of Bipolaris hawaiiensis infection in an equid, and its aggressive clinical course. This case provides important descriptive and prognostic information for horses diagnosed with phaeohyphomycotic rhinitis. A 19-year-old American Quarter Horse mare was presented for second opinion of stertor and exercise intolerance of four-month duration. Endoscopy revealed generalized, proximal nasal edema, and computed tomography identified a soft tissue mass eroded through the rostral nasal bone. Biopsy of the mass was identified as a fungal granuloma caused by B...
Gough SL, Carrick J, Raidal SL, Keane S, Collins N, Cudmore L, Russell CM, Raidal S, Hughes KJ.During 2016-2018, 15 critically ill neonatal foals with acute respiratory distress associated with Chlamydia psittaci infection were presented to three referral hospitals in New South Wales. Chlamydia psittaci has not previously been associated with the development of neonatal respiratory disease. Objective: To investigate and describe the clinical features and outcome of C. psittaci infection in neonatal foals. Methods: Multicentre retrospective case series. Methods: The clinical, clinicopathological, necropsy and histological features of 15 foals with confirmed C. psittaci infection were r...
Velie BD, Smith PM, Fjordbakk CT, Solé M, Jäderkvist Fegraeus K, Rosengren MK, Røed KH, Ihler CF, Lindgren G, Strand E.Dynamic laryngeal collapse (DLC) associated with poll flexion is the most common disorder of the upper respiratory tract (URT) in the Norwegian-Swedish Coldblooded Trotter (NSCT). The disorder, which has also been diagnosed in other breeds of trotters and gaited horses, appears to be related to anatomic phenotypes and only occurs during poll flexion when the horse is exercised 'on the bit'. Objective: Identify genomic regions associated with DLC in the NSCT by combining a rigorous phenotyping protocol with genomic data from a high-density equine genotyping array. Methods: Prospective case/cont...
Willingham-Lane JM, Berghaus LJ, Berghaus RD, Hart KA, Giguère S.The soil-dwelling, saprophytic actinomycete is a facultative intracellular pathogen of macrophages and causes severe bronchopneumonia when inhaled by susceptible foals. Standard treatment for disease is dual-antimicrobial therapy with a macrolide and rifampin. Thoracic ultrasonography and early treatment with antimicrobials prior to the development of clinical signs are used as means of controlling endemic infection on many farms. Concurrently with the increased use of macrolides and rifampin for chemoprophylaxis and the treatment of subclinically affected foals, a significant increase in t...
Poelaert KCK, Van Cleemput J, Laval K, Xie J, Favoreel HW, Nauwynck HJ.The ancestral equine herpesvirus 1 (EHV1), closely related to human herpes viruses, exploits leukocytes to reach its target organs, accordingly evading the immune surveillance system. Circulating EHV1 strains can be divided into abortigenic/neurovirulent, causing reproductive/neurological disorders. Neurovirulent EHV1 more efficiently recruits monocytic CD172a cells to the upper respiratory tract (URT), while abortigenic EHV1 tempers monocyte migration. Whether similar results could be expected for T lymphocytes is not known. Therefore, we questioned whether differences in T cell recruitment c...
Lechmann J, Schoster A, Ernstberger M, Fouché N, Fraefel C, Bachofen C.Equid alphaherpesvirus 1 (EHV-1) infections can have a major impact on the horse industry and equine welfare by causing abortion or respiratory or neurologic disease. A single nucleotide polymorphism (A→G) in open reading frame (ORF) 30, encoding the catalytic subunit of the DNA polymerase, has been shown to be a strong predictive marker for neuropathogenicity. Given that a previously established real-time PCR (rtPCR) protocol yielded unsatisfactory results concerning determination of the EHV-1 genotype, we developed and evaluated a new conventional PCR protocol enabling identification of th...
White S, Moore-Colyer M, Marti E, Coüetil L, Hannant D, Richard EA, Alcocer M.Severe asthma in horses, known as severe equine asthma (SEA), is a prevalent, performance-limiting disease associated with increased allergen-specific immunoglobulin E (IgE) against a range of environmental aeroallergens. Objective: To develop a protein microarray platform to profile IgE against a range of proven and novel environmental proteins in SEA-affected horses. Methods: Six SEA-affected and 6 clinically healthy Warmblood performance horses. Methods: Developed a protein microarray (n = 384) using protein extracts and purified proteins from a large number of families including pollen, ba...
Hwang J, Golla V, Metwali N, Thorne PS.Adverse respiratory health effects in the agricultural industry have been linked to particulate endotoxin exposure. However, whether the endotoxin concentration is significantly correlated to the size of the particle remains an open question. To date, limited research has been conducted to assess particulate endotoxin exposures in the agricultural industry in general or the equine industry in particular. A task-based exposure assessment was conducted to characterize the endotoxin levels of inhalable and respirable particles on four Kentucky farms during the summer season. We conducted personal...
Issouf M, Vargas A, Boivin R, Lavoie JP.Airway wall remodeling, including hyperplasia and hypertrophy of smooth muscle (ASM) cells leading to an increased smooth muscle mass, is considered central to asthma. However, molecular pathways responsible for ASM remodeling remain poorly understood. MicroRNAs (miRNAs) have emerged as key regulators of inflammatory and repair processes affecting the lungs and can downregulate protein expression by inhibiting target mRNA translation. We therefore hypothesized that miRNAs are involved in ASM remodeling in asthma by modulating ASM proliferation. We have analyzed the expression of miRNAs in bron...
Uchida-Fujii E, Niwa H, Kinoshita Y, Nukada T.Actinobacillus species are known to be pathogenic to horses. To clarify etiological agents of actinobacillosis in Japanese adult horses, 27 isolates from Japanese Thoroughbred racehorses putatively identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry as Actinobacillus were further identified by PCR of the A. equuli toxin gene, by CAMP test, and by 16S rRNA sequencing analysis. Actinobacillus equuli subsp. haemolyticus was isolated most frequently (16/27) and was related to respiratory infections. Actinobacillus equuli subsp. equuli (4/27) was isolated from...
Secombe CJ, van Eps AW, Bruce M, Lester GD.To investigate the relationship between bronchoalveolar lavage fluid cytology, particularly mast cells, and airway hyper-reactivity in athletic horses presented for poor performance that included a respiratory tract evaluation in two disparate locations in Australia. Methods: Multi-centre, retrospective and prospective cross-sectional study METHODS: Eighty four adult horses underwent both pulmonary function testing and histamine bronchoprovocation with a commercial flowmetric plethysmography system. A bronchoalveolar lavage was performed four to twelve hours later. Bronchoalveolar lavage fluid...
Airway obstruction is the main trait of severe equine asthma that affects respiratory function and elicits detrimental effects on clinical presentation. Only few and underpowered clinical studies have investigated the impact of improvement in lung function induced by bronchodilators on the clinical signs of asthma-affected horses. Objective: To identify the minimal important difference (MID) in lung function elicited by bronchodilator leading to a meaningful improvement in clinical signs. Methods: Pairwise meta-analysis and meta-regression analysis. Methods: Literature searches were performed ...
Barton AK, Shety T, Klier J, Geis S, Einspanier R, Gehlen H.Inhalation of immunostimulatory bacterial DNA segments (cytosine-phosphate-guanosine-oligodeoxynucleotides, CpG-ODN) normalizes clinical and cytologic parameters in severe equine asthma. We hypothesized that CpG-ODN inhalation also reduces the misbalance of elastinolytic activity in asthmatic horses. Methods: Twenty asthmatic horses diagnosed by clinical examinations using a scoring system were included. All horses inhaled CpG-ODNs for 14 days in 2-day intervals. Matrix metalloproteinase (MMP-2/-9) and tissue inhibitors of metalloproteinase (TIMP-1/-2) concentrations were measured in tracheal ...
Hansen S, Otten ND, Fjeldborg J, Baptiste KE, Horohov DW.The objectives of this study were to evaluate the natural age-related variation and compare the level of pro-inflammatory cytokines in the peripheral blood and lower airways of horses. The mRNA expression of IL-1β, IL-6, IL-8 TNF-α TLR-4 in bronchoalveolar lavage (BAL) fluid and peripheral blood mononuclear cells (PBMC) were studied by quantitative real time polymerase chain reaction (PCR) and differential cell count cytology from 44 horses of different ages. A significant age-related increase was found for the mRNA expression of IL-6, IL-8, TLR-4 and TNF-α in stimulated BAL cells and for T...
Ochi A, Sekiguchi M, Tsujimura K, Kinoshita T, Ueno T, Katayama Y.Equine multinodular pulmonary fibrosis (EMPF) is a recently described form of interstitial pneumonia associated with equine herpesvirus type 5 (EHV-5). This disease has been reported in North and South America, Europe and Oceania but not, to our knowledge, in horses in Japan. We diagnosed EMPF in two Thoroughbred horses in Japan on the basis of gross and histopathological findings. In both cases, significant gross lesions, restricted to the lungs, consisted of numerous firm and coalescing nodules widely distributed throughout the lung. The nodules were <3 cm in diameter and pale white to t...
Claußen G, Grau D, Hessel EF.It has been known for some years now that the occurrence of lameness in horses is closely related to the characteristics of the riding surface and that respiratory tract diseases can be induced by airborne particles. To ensure both optimal rideability (e.g., grip, elasticity, etc.) and low dust production, riding surfaces have to be regularly attended to, which also includes watering the floor. However, at present, it is not known what the individual moisture content of the various types of riding surface should be to ensure optimal rideability or what their potential for releasing dust is at ...
Dall Agnol AM, Beuttemmuller EA, Pilz D, Leme RA, Saporiti V, Headley SA, Alfieri AF, Alfieri AA.Equid gammaherpesvirus 2 (EHV-2) and 5 (EHV-5) are members of the Herpesviridae family and have been reported in horse populations worldwide. This study aimed to evaluate the presence of herpesvirus DNA in the upper respiratory tract of horses. Twenty-six nasal swabs were collected from asymptomatic adult horses of two different horse farms (A, n = 18; B, n = 8), both located in Southern Brazil. The EHV-1, EHV-2, EHV-4, and EHV-5 DNA analyses were performed using nested PCR assays targeting the glycoprotein B gene. Four (15.3%) and 12 (46.1%) of the 26 nasal swab samples were positive ...
Tessier L, Côté O, Bienzle D.Severe equine asthma is a chronic inflammatory disease of the lung in horses similar to low-Th2 late-onset asthma in humans. This study aimed to determine the utility of RNA-Seq to call gene sequence variants, and to identify sequence variants of potential relevance to the pathogenesis of asthma. Methods: RNA-Seq data were generated from endobronchial biopsies collected from six asthmatic and seven non-asthmatic horses before and after challenge (26 samples total). Sequences were aligned to the equine genome with Spliced Transcripts Alignment to Reference software. Read preparation for sequenc...
de Lagarde M, Rodrigues N, Chevigny M, Beauchamp G, Albrecht B, Lavoie JP.Bronchospasm results in airway obstruction in horses with heaves. Atropine is the most potent bronchodilator drug currently available for horses, but is associated with side effects that limit its use. Like atropine, N-butylscopolammonium bromide (NBB) is an anticholinergic agent with bronchodilatory properties. Objective: To compare the bronchodilating effects and side effects of atropine and NBB in horses with heaves. Methods: Cross-over experiment using horses with heaves. Methods: Eight horses with heaves were administered atropine and NBB, using a cross-over design. Heart rate, pupillary ...
Ahern BJ, Parente EJ.Upper respiratory abnormalities are common performance-limiting problems in horses. The complications of various treatment methods, including laryngoplasty surgery, sinus surgery, intermittent dorsal displacement of the soft palate, laser surgery, and tracheal disorders, are discussed.
Morley PS, Townsend HG, Bogdan JR, Haines DM.To identify risk factors associated with respiratory tract disease in horses during 3 epidemics caused by influenza virus infections. Methods: Cross-sectional and prospective longitudinal observational studies. Methods: 1,163 horses stabled at a Thoroughbred racetrack. Methods: Investigations were conducted during a 3-year period. An epidemic of respiratory tract disease caused by influenza virus infections was identified in each year. Routine observations and physical examinations were used to classify horses' disease status. Data were analyzed to identify factors associated with development ...
Lange-Consiglio A, Stucchi L, Zucca E, Lavoie JP, Cremonesi F, Ferrucci F.Human asthma is a widespread disease associated with chronic inflammation of the airways, leading to loss of quality of life, disability and death. Corticosteroid administration is the mainstream treatment for asthmatic patients. Corticosteroids reduce airway obstruction and improve quality of life, although symptoms persist despite treatment in many patients. Moreover, available therapies failed to reverse the lung pathology present in asthma. Animal models, mostly rats and mice, in which the disease is experimentally induced, have been studied to identify new therapeutic targets for human as...
Boivin R, Vargas A, Lefebvre-Lavoie J, Lauzon AM, Lavoie JP.Overexpression of the (+)insert smooth muscle myosin heavy chain (SMMHC) isoform could contribute to airway bronchospasm by increasing the velocity of contraction. Whether the (+)insert isoform is present in the small airways and its expression is reversible in asthma are unknown. Objective: To determine the anatomical location and the expression kinetics of the (+)insert SMMHC isoform in airways of horses with heaves and to evaluate its modulation in response to disease status. Methods: We evaluated the (+)insert SMMHC isoform in the airways of horses with heaves during disease exacerbation a...
Jose-Cunilleras E, Kohn CW, Hillier A, Saville WJ, Lorch G.To compare responses to a variety of intradermally injected allergens among healthy horses and horses with chronic obstructive pulmonary disease (COPD), recurrent urticaria (RU), and atopic dermatitis-insect hypersensitivity (allergic dermatitis [AD]). Methods: Case-control study. Methods: 86 horses. Methods: Results of intradermal testing for horses with COPD, RU, or AD were compared with results for healthy horses. Results: Compared with healthy horses, horses with COPD, RU, and AD were significantly more likely to have positive (> or = 3+) reactions to intradermal allergens (molds, weeds, t...
Franklin SH, Naylor JR, Lane JG.Videoendoscopy of the upper respiratory tract (URT) during high-speed treadmill exercise has proved to be invaluable in the assessment of URT dysfunction in racehorses. However, very little information exists regarding dynamic airway collapse in other sport horses used in nonracing equestrian disciplines. Objective: To evaluate the videoendoscopic findings at rest and during exercise in a mixed population of sport horses referred for investigation of poor athletic performance and/or abnormal respiratory noise. Methods: Videoendoscopy of the upper airway was performed at rest and during high-sp...
Gough SL, Carrick J, Raidal SL, Keane S, Collins N, Cudmore L, Russell CM, Raidal S, Hughes KJ.During 2016-2018, 15 critically ill neonatal foals with acute respiratory distress associated with Chlamydia psittaci infection were presented to three referral hospitals in New South Wales. Chlamydia psittaci has not previously been associated with the development of neonatal respiratory disease. Objective: To investigate and describe the clinical features and outcome of C. psittaci infection in neonatal foals. Methods: Multicentre retrospective case series. Methods: The clinical, clinicopathological, necropsy and histological features of 15 foals with confirmed C. psittaci infection were r...
Sarkar S, Balasuriya UB, Horohov DW, Chambers TM.Equine herpesvirus-1 (EHV-1) is one of the most common and important respiratory viral pathogens of horses. EHV-1 in horses replicates initially in the respiratory epithelium and then spreads systematically to endothelial cells lining the small blood vessels in the uterus and spinal cord, and highly pathogenic virus strains can produce aborted fetuses or myeloencephalopathy. Like other herpes viruses, EHV-1 employs a variety of mechanisms for immune evasion. Some herpes viruses down-regulate the type-I interferon (IFN) response to infection, but such activity has not been described for EHV-1. ...
Borlone C, Morales N, Henriquez C, Folch H, Olave C, Sarmiento J, Uberti B, Moran G.Neutrophils participate in innate immunity as the first line of host defense against microorganisms. However, exacerbated neutrophil activity can be harmful to surrounding tissues; this is important in a range of diseases, including allergic asthma and chronic obstructive pulmonary disease in humans, and equine asthma (also known as recurrent airway obstruction (RAO). Tamoxifen (TX) is a non-steroidal estrogen receptor modulator with effects on cell growth and survival. Previous preliminary studies showed that TX treatment in horses with induced acute pulmonary inflammation promoted early apop...
Kimbell-Dunn M, Bradshaw L, Slater T, Erkinjuntti-Pekkanen R, Fishwick D, Pearce N.To examine the prevalence of symptoms of asthma and allergy in different farming groups in New Zealand. Methods: A postal questionnaire was sent to a random sample of 2,500 farmers throughout New Zealand. Results: The response rate was 77% (1,706 of 2,203 eligibles). The 12-month period prevalence of current asthma was 11.8% overall, compared with 15% in the general population. Asthma prevalence was higher for horse breeders/groomers (16.5%), pig farmers (18.2%), poultry farmers (17.4%), and those working with oats (17.4%). Asthma was also significantly elevated among those working with cleani...
Courouce-Malblanc A, Deniau V, Rossignol F, Corde R, Leleu C, Maillard K, Pitel PH, Pronost S, Fortier G.Dorsal displacement of the soft palate (DDSP) is one of the most common obstructive conditions of the upper respiratory tract in the racehorse. This condition has a complex aetiology which may be caused or exacerbated by pharyngeal inflammation. Additionally, lower respiratory airway diseases may be associated with DDSP thereby contributing to exercise intolerance in these horses. Objective: The aim of this study was to measure physiological variables during a standardised exercise test and to assess the prevalence and consequences of lower respiratory airway disease in horses with DDSP. Metho...
Klier J, Lehmann B, Fuchs S, Reese S, Hirschmann A, Coester C, Winter G, Gehlen H.Recurrent airway obstruction (RAO), an asthma-like disease, is 1 of the most common allergic diseases in horses in the northern hemisphere. Hypersensitivity reactions to environmental antigens cause an allergic inflammatory response in the equine airways. Cytosine-phosphate-guanosine-oligodeoxynucleotides (CpG-ODN) are known to direct the immune system toward a Th1-pathway, and away from the pro-allergic Th2-line (Th2/Th1-shift). Gelatin nanoparticles (GNPs) are biocompatible and biodegradable immunological inert drug delivery systems that protect CpG-ODN against nuclease degeneration. Prelimi...
Pacheco AP, Paradis MR, Hoffman AM, Hermida P, Sanchez A, Nadeau JA, Tufts M, Mazan MR.Despite the increasing number of geriatric horses attended by veterinarians, there is a lack of understanding of aging-related changes on the respiratory system of horses. Objective: To identify aging-related changes on the respiratory function and bronchoalveolar lavage fluid (BALF) cytology of horses. Methods: Fifteen healthy young adult (2-11 years) and 16 healthy aged (≥20 years) horses. Methods: The respiratory system was examined by measurement of arterial blood gases (ABG), use of respiratory inductive plethysmography (RIP) for assessment of breathing pattern and ventilatory paramet...
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...
Gehlen H, Oey L, Rohn K, Bilzer T, Stadler P.Chronic pulmonary diseases (recurrent airway obstruction [RAO]) have been reported to alter skeletal muscle cells in humans. The purpose of this study was to evaluate a potential relationship between pulmonary and muscle variables in horses with a clinical diagnosis of RAO. Muscle biopsies from healthy horses and from horses with RAO were investigated and the relationship between the severity of lung disease and the degree of muscular changes was determined. Objective: We hypothesized that chronic pulmonary disease can lead to changes of the skeletal muscle in horses. Methods: Fifteen healthy ...
Stadler P, Deegen E.Dynamic compliance, airway resistance, viscous work and respiratory frequency were measured at intervals in horses over 12 h periods. Variation, daily averages and circadian patterns were recorded. Examinations were performed on 24 horses. They were divided into three groups: Normal horses, horses with chronic latent bronchitis and horses with manifest chronic obstructive pulmonary disease (COPD). Significant differences were found between the daily averages and the fluctuations when the normal group and the COPD group were compared. In most cases differences between all three groups were sign...
Art T, Kirschvink N, Smith N, Lekeux P.To test the hypothesis that reactive oxygen species could be associated to the lower airway disorders occurring in horses suffering from recurrent airway obstruction (RAO), indices of oxidative stress were studied in blood and pulmonary epithelium lining fluid in 5 RAO horses either in clinical remission or 24 h after the onset of a crisis of bronchospasm and in 5 healthy horses. Venous blood and bronchoalveolar lavage fluid (BALF) samples were collected and analysed for reduced glutathione (GSH), oxidised glutathione (GSSG), total glutathione (TGSH), glutathione redox ratio (GRR) in blood hae...
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...
Bordin AI, Cohen ND, Giguère S, Bray JM, Berghaus LJ, Scott B, Johnson R, Hook M.Pneumonia caused by the intracellular bacterium Rhodococcus equi is an important cause of disease and death in immunocompromised hosts, especially foals. Antibiotics are the standard of care for treating R. equi pneumonia in foals, and adjunctive therapies are needed. We tested whether nebulization with TLR agonists (PUL-042) in foals would improve innate immunity and reduce the severity and duration of pneumonia following R. equi infection. Neonatal foals (n = 48) were nebulized with either PUL-042 or vehicle, and their lung cells infected ex vivo. PUL-042 increased inflammatory cytokines...
Mureşan A, Mureşan C, Siteavu M, Avram E, Bochynska D, Taulescu M.Equine herpesviruses are important pathogens causing significant economic loss in equine and asinine populations. EHV-1/4 strains are mainly associated with respiratory distress. The aim of this study is to report the first EHV 4-associated respiratory disease in donkeys in Romania. Thirty-seven of three hundred jennies in an ecological donkey farm in southwest Romania started initially showing signs of severe upper respiratory tract disease, with ten concomitant late abortions/neonatal deaths and three neurological cases. There were nine fatalities. Pathological examination was performed, and...
Aharonson-Raz K, Lohmann KL, Townsend HG, Marques F, Singh B.Heaves, an obstructive neutrophilic airway inflammation of horses, is triggered by dust components such as endotoxin and has similarities to human asthma. Pulmonary intravascular macrophages (PIMs) increase horses' sensitivity to endotoxin-induced lung inflammation; however, their role in an airborne pathology remains unknown. Therefore, we investigated the role of PIMs in the development of heaves in horses. Clinical and inflammatory responses were evaluated following induction of heaves by moldy hay exposure and PIM depletion with gadolinium chloride (GC). Mares (N = 9) were exposed to four ...
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 ...
Patel JR, Földi J, Bateman H, Williams J, Didlick S, Stark R.The temperature sensitive and host range mutant clone 147 of equine herpesvirus 1 (EHV-1) was assessed for its ability to protect conventional, susceptible adult horses against respiratory infection by EHV-1 and equine herpesvirus 4 (EHV-4). Intranasal (IN) vaccination with 5.2 log(10) TCID(50) did not cause adverse clinical reactions although a limited virus shedding and viraemia (leukocytes) was observed in 11 of 15 and 10 of 15 vaccinated horses respectively. All 15 vaccinated horses showed a significant seroresponse to both EHV-1 and EHV-4 for virus neutralising (VN) antibody. None of 14 c...
Whalley JM, Ruitenberg KM, Sullivan K, Seshadri L, Hansen K, Birch D, Gilkerson JR, Wellington JE.Equine herpesviruses 1 and 4 (EHV-1 and EHV-4) cause equine respiratory disease worldwide. However, only EHV-1 is a cause of abortion and neurological disease, despite the two viruses having all 76 genes in common. In addition EHV-1 has a broader host range in cell culture than EHV-4, as exemplified by the rabbit kidney (RK) cell line that is permissive for EHV-1, but not for EHV-4. Here we describe that when EHV-4 produced in equine cells was inoculated onto RK cells expressing glycoprotein D of EHV-1 (RKgD1), infection developed as clusters of rounded cells, and this infectivity could be pas...
Breathnach CC, Yeargan MR, Sheoran AS, Allen GP.Equine herpesvirus-1 (EHV-1) remains a frequent cause of upper respiratory tract infection and abortion in horses worldwide. However, little is known about the local antibody response elicited in the upper airways of horses following exposure to EHV-1. This study analysed the mucosal humoral immune response of weanling foals following experimental infection with virulent EHV-1, or vaccination with either of 2 commercial vaccines. Twenty weanlings were assigned to 5 groups and were inoculated with, or vaccinated against, EHV-1 following different regimens. Finally, all weanlings were simultaneo...
Patel JR, Bateman H, Williams J, Didlick S.A German abortion isolate of EHV-1 (strain M8) was grown in equine dermal (ED) cells at a low multiplicity of infection in presence of 5-bromo-2-deoxy uridine. The resulting stock was dialysed, titrated and cloned by terminal dilution in ED cells grown in 96-well microtitration plates. Of 192 clones each originating from a single focus, clone 147 (C147) was found to be restricted for growth at and above temperatures of 38.5 degrees C. It was also restricted for growth at 37 degrees C in rabbit kidney (RK-13) cells which are widely used for the isolation and titration of EHV-1; hence clone 147 ...
Mumford EL, Traub-Dargatz JL, Carman J, Callan RJ, Collins JK, Goltz KL, Romm SR, Tarr SF, Salman MD.Horses vaccinated against common agents of infectious upper respiratory disease (IURD) may not have detectable serum antibody and may not be protected from clinical disease. Objective: The objectives of this study were to 1) investigate the serological response of horses to vaccination against influenza virus (H3N8 and H7N7) and equine herpesviruses (EHV) in a field setting and 2) evaluate associations among vaccination status, serum antibody concentrations, and occurrences of IURD in monitored horses. Methods: In this study, horses on 6 Colorado premises were vaccinated parenterally against i...
Sage SE, Nicholson P, Peters LM, Leeb T, Jagannathan V, Gerber V.The transcriptomic profile of a cell population can now be studied at the cellular level using single-cell mRNA sequencing (scRNA-seq). This novel technique provides the unprecedented opportunity to explore the cellular composition of the bronchoalveolar lavage fluid (BALF) of the horse, a species for which cell type markers are poorly described. Here, scRNA-seq technology was applied to cryopreserved equine BALF cells. Analysis of 4,631 cells isolated from three asthmatic horses in remission identified 16 cell clusters belonging to six major cell types: monocytes/macrophages, T cells, B/plasm...
