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.
Hackett ES, Traub-Dargatz JL, Knowles JE, Tarr SF, Dargatz DA.Arterial blood gas analysis is widely accepted as a diagnostic tool to assess respiratory function in neonates. To the authors' knowledge, there are no published reports of arterial blood gas parameters in normal neonatal foals at altitude. Objective: To provide information on arterial blood gas parameters of normal foals born at 1500 m elevation (Fort Collins, Colorado) in the first 48 h post partum. Objective: Foals born at 1500 m will have lower PaO2 and PaCO2 than foals born at sea level due to low inspired oxygen and compensatory hyperventilation occurring at altitude. Methods: Sixteen fo...
Neuhaus S, Bruendler P, Frey CF, Gottstein B, Doherr MG, Gerber V.Equine recurrent airway obstruction (RAO) shares many characteristics with human asthma. In humans, an inverse relationship between susceptibility to asthma and resistance to parasites is suspected. Objective: Members of a high-incidence RAO half-sibling family (F) shed fewer strongylid eggs compared with RAO-unaffected pasture mates (PM) and that RAO-affected horses shed fewer eggs than RAO-unaffected half-siblings. Methods: Seventy-three F and 73 unrelated, age matched PM. Methods: Cases and controls kept under the same management and deworming regime were examined. Each individual was class...
Cramp P, Derksen FJ, Stick JA, Nickels FA, Brown KE, Robinson P, Robinson NE.Little is known about the efficacy of bilateral ventriculectomy (VE) or bilateral ventriculocordectomy (VCE) in draught horses. Objective: To compare the effect of VE and VCE on upper airway noise in draught horses with recurrent laryngeal neuropathy (RLN) by use of quantitative sound analysis techniques. Objective: In competitive draught horses with grade 4 RLN, VE and VCE reduce upper airway noise during exercise, but VCE is more effective. Methods: Thirty competitive hitch or pulling draught horses with grade 4 RLN were evaluated for upper airway sound during exercise. Respiratory rate (RR)...
Morán G, Burgos R, Araya O, Folch H.In horses, Recurrent Airway Obstruction (RAO) is an allergic disease that involves IgE mediated Type I Hypersensitivity responses. The development of this type of allergy involves a series of events that begins with reaginic antibodies, mainly IgE and some IgG subclasses. These reaginic antibodies bind with high affinity, via the Fc portion, to FcepsilonRI receptors on the membrane of mast cells and basophils. Once bound, environmental allergens cross-link the antibodies, which results in mast cell degranulation leading to the production of histamine and other chemical mediators that act toget...
TSUJIMURA K, SHIOSE T, YAMANAKA T, NEMOTO M, KONDO T, MATSUMURA T.An equine herpesvirus type 1 (EHV-1) mutant, DeltagE, defective in glycoprotein E (gE) was evaluated as a modified live virus (MLV) vaccine. Colostrum-deprived Thoroughbred foals inoculated intranasally (i.n.) or intramuscularly (i.m.) with DeltagE did not exhibit any clinical signs of respiratory disease except for a mild nasal discharge in 1 i.n. inoculated foal on Days 1 and 3 post-infection. In contrast, the intranasal inoculation of foals with the revertant of DeltagE resulted in biphasic pyrexia, mucopurulent nasal discharge and swelling of submandibular lymph nodes. These results indica...
Milillo P, Traversa D, Elia G, Otranto D.Larvae of Rhinoestrus spp. (Diptera, Oestridae) infect nasal and sinus cavities of horses, causing a nasal myiasis characterized by severe respiratory distress. Presently, the diagnosis of horse nasal botfly relies on the observation of clinical signs, on the post mortem retrieval of larvae or on molecular assays performed using pharyngeal swabs. The present study was carried out to characterize larval somatic proteins and salivary glands of Rhinoestrus spp. in a preliminary assessment towards the immunodiagnosis of equine rhinoestrosis. Out of the 212 necropsied horses 13 were positive for th...
Schwab UE, Fulcher ML, Randell SH, Flaminio MJ, Russell DG.We describe a method for creating differentiated equine bronchial epithelial cell cultures that can be used for in vitro studies including airway disease mechanisms and pathogen-host interactions. Our method is based on the culturing of human tracheobronchial epithelial cells at an air-liquid interface (ALI) in specific serum-free, hormone-supplemented medium. Bronchial epithelial cells are isolated and grown on T-Clear® insert membranes. Within 2 to 3 wk, cells differentiate into ciliated and mucus producing cells as demonstrated by confocal and electron microscopy. Furthermore, the demonstr...
Smit LA, Wouters IM, Heederik D, Douwes J.Endotoxins are cell-wall components of Gram-negative bacteria that are commonly present in plants and plant products and in faecal matter. This review presents an overview of endotoxin exposure levels, associated health effects, and relevance regarding veterinary practice. Exposure to airborne endotoxin is especially high in the agricultural sector and among veterinarians, and in particular among those working with horses or farm animals. Inhalation of endotoxins may cause acute airway inflammation and respiratory symptoms that can lead to (non-allergic) asthma and chronic obstructive pulmonar...
Ramery E, Fievez L, Fraipont A, Bureau F, Lekeux P.The long pentraxin 3 (PTX3) plays an important role in host defence and its over-expression may contribute to airway injury. The aim of the present study was therefore to characterize in more detail PTX3 and its expression in the horses' airway. Six healthy horses and six horses affected by recurrent airway obstruction (R.A.O.) were submitted to a dusty environment challenge. PTX3 DNA and cDNA were cloned and sequenced. PTX3 expression was evaluated by RT-qPCR, Western blotting and immunohistochemistry in bronchoalveolar lavage fluid (BALF) cells, BALF supernatant and bronchial epithelial cell...
Gryspeerdt AC, Vandekerckhove AP, Garré B, Barbé F, Van de Walle GR, Nauwynck HJ.Equine herpesvirus 1 (EHV1) replicates in the respiratory tract of horses, after which infected leukocytes transport virus throughout the body, resulting in abortion or nervous system disorders. Two EHV1 strains circulate in the field: neurovirulent and non-neurovirulent. To investigate differences in replication in the upper respiratory tract (URT), an experimental inoculation study in ponies was performed with both strains. Two groups of six ponies, were inoculated intranasally with 10(6.5) TCID(50) of either strain. Clinical signs, nasal shedding and viremia were evaluated. At early time po...
Lu Z, Chambers TM, Boliar S, Branscum AJ, Sturgill TL, Timoney PJ, Reedy SE, Tudor LR, Dubovi EJ, Vickers ML, Sells S, Balasuriya UB.The objective of this study was to develop and evaluate new TaqMan real-time reverse transcription-PCR (rRT-PCR) assays by the use of the minor groove binding probe to detect a wide range of equine influenza virus (EIV) strains comprising both subtypes of the virus (H3N8 and H7N7). A total of eight rRT-PCR assays were developed, targeting the nucleoprotein (NP), matrix (M), and hemagglutinin (HA) genes of the two EIV subtypes. None of the eight assays cross-reacted with any of the other known equine respiratory viruses. Three rRT-PCR assays (EqFlu NP, M, and HA3) which can detect strains of th...
Retteg Pauls S, Jottini S, Takai S, Venner M, Wohlsein P.A 3-month-old female trotter foal was euthanized due to severe dyspnoea. Pathomorphologically a chronic granulomatous to necrotizing pneumonia was found and Rhodoccocus (R.) equi was isolated microbiologically. An immunohistological method using a murine monoclonal antibody against a 15-17 kDa antigen of virulent R. equi was established in formalin-fixed and paraffin-embedded tissue sections using various antigen retrieval techniques to optimize the staining results. Microwave treatment was most suitable for the demonstration of bacterial antigen localized predominantly in intralesional macrop...
Ryu SH, Koo HC, Park YK, Kim JM, Jung WK, Davis WC, Park YH, Lee CW.Equine respiratory disease is a common cause of poor performance and training interruptions. The higher incidence rate of infectious upper respiratory disease (IURD) in thoroughbred racehorses at the Seoul Race Park coincided with the frequent stabling season, shorter stabling periods, and younger ages in this study. Incidence rates were also correlated with significantly lower proportions of cells expressing MHC class II-, CD2 antigen-, CD4+- or CD8+-T lymphocyte-, and B lymphocyte in IURD patients compared with healthy control groups in the summer and fall and in 2-and-3-year-old groups. The...
Kummer M, Gygax D, Jackson M, Bettschart-Wolfensberger R, Fürst A.Complications associated with equine castration can have medical and financial consequences. This retrospective study investigated a novel method of castration via an inguinal approach in mature stallions and compared the incidence of complications with other methods. Objective: Castration via an inguinal approach has a low complication rate at the site of surgery compared with other castration techniques. Methods: Mature stallions (n = 238) were castrated under general anaesthesia in dorsal recumbency using an inguinal approach. The vaginal process was incised, the spermatic cord ligated twic...
Carstens A, Kirberger RM, Grimbeek RJ, Donnellan CM, Saulez MN.Radiographic measurement of tracheal dimensions in the horse may be useful in evaluating upper and lower respiratory tract conditions due to the gradient of pressure changes between these areas. Lateral radiographs of the trachea of 15 normal sedated Thoroughbred horses were made at inspiration and expiration and magnification-corrected mean airway heights measured were, respectively: larynx: 5.89 and 5.86 cm; trachea at the third cervical vertebra (C3): 4.17 and 4.04cm; at the fifth cervical vertebra (C5): 3.62 and 3.59 cm; at the first thoracic vertebra (T1): 3.4 and 3.23cm; and carina: 3.85...
Swinburne JE, Bogle H, Klukowska-Rötzler J, Drögemüller M, Leeb T, Temperton E, Dolf G, Gerber V.Recurrent airway obstruction (RAO), or heaves, is a naturally occurring asthma-like disease that is related to sensitisation and exposure to mouldy hay and has a familial basis with a complex mode of inheritance. A genome-wide scanning approach using two half-sibling families was taken in order to locate the chromosome regions that contribute to the inherited component of this condition in these families. Initially, a panel of 250 microsatellite markers, which were chosen as a well-spaced, polymorphic selection covering the 31 equine autosomes, was used to genotype the two half-sibling familie...
Winther L, Andersen RM, Baptiste KE, Aalbæk B, Guardabassi L.Stenotrophomonas maltophilia is being reported with increasing frequency as a human nosocomial pathogen, especially among immuno-compromised patients. To the authors' knowledge, this pathogen has not previously been associated with lower airway disease in the horse. In this paper the clinical findings, laboratory diagnosis and response to treatment of seven cases of respiratory infection with S. maltophilia in horses, presented at three equine referral hospitals in Denmark in 2007, are described. In all cases there was a clinical history of chronic coughing and abundant mucopurulent exudate wa...
Robinson NE, Berney C, Behan A, Derksen FJ.Efficacy of inhaled fluticasone propionate (FP) for management of recurrent airway obstruction (RAO) has only been evaluated after several weeks' treatment. Objective: To compare efficacy of (1) 3-day treatments with FP to dexamethasone (DEX) for management of RAO; and (2) FP and DEX to no treatment in prevention of acute RAO exacerbations. Methods: Nine RAO affected horses. Methods: Crossover studies in RAO-affected horses compared (a) 3-day treatment of RAO exacerbation with FP (3 and 6 mg q12h) and DEX (0.1 mg/kg q24h) and (b) FP (6 mg q12h) and DEX (0.1 mg/kg q24h) to no treatment for prev...
Bugno M, Slota E, Witarski W, Gerber V, Klukowska-Roetzler J.The results obtained in the present study enabled the physical map of the donkey genome to be extended with markers associated with recurrent airway obstruction (RAO), a major performance-limiting disease of Equidae. The equine BAC clone containing the IL4R and CLCA1 genes were localized to EAS 14q13 and EAS 6q15 respectlivy by fluorescent in situ hybridization. Identification of their locus confirmed the distribution of syntenic regions between the domestic horse and the domestic donkey within the chromosomes analysed.
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...
Nolen-Walston RD, Kuehn H, Boston RC, Mazan MR, Wilkins PA, Bruns S, Hoffman AM.Inflammatory airway disease has a high prevalence in horses, but is often a diagnostic challenge. Flowmetric plethysmography and histamine bronchoprovocation (FP/HBP) is a simple and effective tool for diagnosis, but reproducibility of these measurements made over time has not been established. Objective: We hypothesize that the measurement of airway responsiveness in horses using FP/HBP is consistent over both short and long periods of time. Methods: Twenty-nine healthy adult horses from 2 university herds. Methods: In this prospective experimental study, airway responsiveness was determined ...
Reperant LA, Rimmelzwaan GF, Kuiken T.Highly pathogenic avian influenza viruses of subtype H5N1 are remarkable because of their expanding non-avian host range and wide tissue tropism. They have caused severe or fatal respiratory and extra-respiratory disease in seven naturally infected species of carnivore. However, they are not unique in their ability to cross the species barrier, to cause clinical disease and mortality, or to replicate in extra-respiratory organs. Low pathogenic avian influenza viruses have crossed from birds to swine, horses, harbour seals, whales and mink; have resulted in severe respiratory disease and mortal...
Emenius G, Merritt AS, Härfast B.To protect susceptible subjects from exposure to horse allergen, a Swedish national report recommended a distance of at least 500 m between homes and stables and other areas with horses. The aim of this project was to study indoor and outdoor levels of horse allergen in relation to distance from stables and horse tracks. Methods: Indoor and outdoor samples were collected with Petri dishes at 49 sites in different housing areas and near to a track for trotting horses. In the apartments, Petri dishes were placed on a bookshelf in the living room at a height of approximately 1.5 m. Outdoors, cage...
Richard EA, Fortier GD, Denoix JM, Art T, Lekeux PM, Van Erck E.Inflammatory airway disease (IAD) is a nonseptic condition of the lower respiratory tract. Its negative impact on respiratory function has previously been described using either forced expiration or forced oscillations techniques. However, sedation or drug-induced bronchoconstriction were usually required. The impulse oscillometry system (IOS) is a noninvasive and sensitive respiratory function test validated in horses, which could be useful to evaluate IAD-affected horses without further procedures. Objective: To determine the sensitivity of IOS in detecting alterations of the respiratory fun...
Albini S, Abril C, Franchini M, Hüssy D, Filioussis G.Stenotrophomonas maltophilia (S. maltophilia) is a nonfermentative bacterium, which is naturally resistant against a panel of commonly-used antibiotics. It is frequently isolated from humans with chronic respiratory disease, e.g. cystic fibrosis or chronic obstructive pulmonary disease. In veterinary medicine S. maltophilia is perceived to be a mere coloniser. We herewith report 7 strains of S. maltophilia isolated from animals, of which 5 strains were harvested from 3 horses, a dog and a cat with chronic respiratory disease. The dog isolate showed resistance to trimethoprim / sulphamethoxazol...
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...
Andrade FS, Facó LL, Ida KK, Silva LC, Fantoni DT, Ambrósio AM.To compare static compliance (C) and alveolar-arterial oxygen tension difference [P(a-a)O] between positive end-expiratory pressures (PEEP) of 7, 12 and 17 cmHO applied after an alveolar recruitment maneuver (RM) in isoflurane-anesthetized horses. Methods: Prospective, randomized, clinical study. Methods: A group of 30 healthy adult horses undergoing arthroscopic surgery. Methods: Animals in dorsal recumbency and mechanically ventilated with a tidal volume of 14 mL kg and 7 cmHO PEEP (control; n = 6) were subjected to an RM by increasing PEEP from 7 to 22 cmHO in 5 cmHO increments at 5 minute...
Murphy JR, McPherson EA, Dixon PM.The effects of the bronchodilator drugs, atropine, isoprenaline and terbutaline, on normal horses and on horses affected with chronic obstructive pulmonary disease (COPD), were assessed by pulmonary function tests and clinical examination. Normal horses were not affected but COPD horses responded by a marked decrease in intrathoracic pressure, a decrease in respiratory rate, an initial decrease followed by an increase in arterial oxygen partial pressure and clinical improvement after treatment with all 3 drugs. These changes were temporary.
Wilson ME, Berney C, Behan AL, Robinson NE.Lidocaine decreases neutrophilic inflammation in models of acute lung injury and decreases inflammation in asthmatic patients. Neutrophilic bronchiolitis develops in recurrent airway obstruction (RAO), but it remains unknown if lidocaine infusion decreases neutrophil migration into the airways. Objective: Lidocaine decreases neutrophilic inflammation as measured in BALF in RAO-affected horses. Methods: Six RAO-susceptible horses in remission. Methods: In a randomized cross-over design, horses received lactated Ringer's solution (LRS) IV or lidocaine hydrochloride IV with a minimum of 4 weeks a...
Tee SY, Dart AJ, MacDonald MH, Perkins NR, Horadagoda N, Jeffcott LB.To evaluate the effect of collecting serial tracheal aspirate (TA) and bronchoalveolar lavage (BAL) samples on the cytological findings of subsequent fluid samples obtained from horses without clinical signs of respiratory disease. Methods: Experimental. Methods: Six healthy Standardbred horses. Methods: Endoscopically-guided TA samples, and BAL samples collected using the blind field technique were obtained from the six horses on days 1, 2, 3, 4, 5, 12, and 17. On day 17, horses were sampled three times: at baseline and at 2.5 h and 4 h apart. The differential cytology of the fluid samples co...
Chand N, Eyre P.Nonsteroidal anti-inflammatory drugs inhibit the biosynthesis of kinins and prostaglandins and stabilize leukocyte lysosomal membranes. Nonsteroidal anti-inflammatory drugs also weakly block the biosynthesis of histamine and serotonin, and pharmacologically antagonize kinins, prostaglandins and slow-reacting substance of anaphylaxis. Nonsteroidal anti-inflammatory drugs effectively control both cardiovascular and respiratory manifestations of hypersensitivity in cattle and horses. This, coupled with the contrasting lack of effectiveness of "antiamine" drugs, suggests that bio-amines such as hi...
Clarke AF.This paper reviews the environmental and host factors which interact to affect the incidence and severity of episodes of respiratory disease in stabled horses. The folly of accepting housing criteria and management practices for the horse, based on direct extrapolations from intensive housing of meat producing animals, is discussed. The factors which affect air hygiene and physical environment of stables are considered in terms of short-term athletic performance and long-term welfare.
Barton AK, Heinemann H, Schenk I, Machnik M, Gehlen H.OBJECTIVE To evaluate the influence of respiratory tract disease (ie, recurrent airway obstruction [RAO]) and mode of inhalation on detectability of inhaled budesonide in equine plasma and urine samples. ANIMALS 16 horses (8 healthy control horses and 8 horses affected by RAO, as determined by results of clinical examination, blood gas analysis, bronchoscopy, and cytologic examination of bronchoalveolar lavage fluid). PROCEDURES 4 horses of each group inhaled budesonide (3 μg/kg) twice daily for 10 days while at rest, and the remaining 4 horses of each group inhaled budesonide during lunging ...
Derksen FJ, Williams KJ, Uhal BD, Slocombe RF, de Feijter-Rupp H, Eberhart S, Berney C, Robinson NE.Exercise-induced pulmonary haemorrhage (EIPH) occurs in the majority of horses performing strenuous exercise. Associated pulmonary lesions include alveolar and airway wall fibrosis, which may enhance the severity of EIPH. Further work is required to understand the pulmonary response to blood in the equine airways. Objective: To confirm that a single instillation of autologous blood into horse airways is associated with alveolar wall fibrosis, and to determine if blood in the airways is also associated with peribronchiolar fibrosis. Methods: Paired regions of each lung were inoculated with bloo...
Stopyra A, Sobiech P, Waclawska-Matyjasik A.The acid-base equilibrium is closely linked to gas exchange in the lungs, and respiratory exchange ratios are used to evaluate respiratory effectiveness and tissue oxygen levels. Acid-base indicators are determined in both arterial and venous blood samples. This study compares the usefulness of acid-base indicators of venous and arterial blood in monitoring the condition of horses with recurrent airway obstruction. Prior to treatment involving bronchodilating glucocorticoids, expectorant and mucolytic drugs, more pronounced changes were observed in venous blood (pH 7.283, pCO2 61.92 mmHg, pO2 ...
Mair TS, Lane JG.Case records are reviewed of 51 adult horses in which a diagnosis of pneumonia, pulmonary abscess or pleuritis had been made. Forty-five horses were afflicted with pneumonia and/or pulmonary abscesses; in 11 of these the infection was primary, whereas in 34 it was secondary to another disease process (inhalation of food or saliva, thoracic trauma, generalised infection, airway disease, neoplasia or thromboembolism). Of the 11 horses with primary pulmonary infections, 10 appeared to be associated with a previous episode of stress; this took the form of long distance travel in eight cases. There...
Davis EG, Rush BR, Blecha F.Immunomodulation with Propionibacterium acnes is used for prophylaxis of respiratory disease or in horses suffering from chronic pulmonary inflammation; however, the mechanism for this response is poorly understood. Semiquantitative reverse transcriptase-polymerase chain reaction assays were used to evaluate gene expression of interleukin (IL)-2, IL-10, interferon (IFN)-gamma, and NK-lysin in healthy horses treated with P. acnes. Findings in the study indicated that horses treated with a P. acnes-based immunomodulator exhibited increased IFN-gamma and NK-lysin gene expression in peripheral blo...
Zarski LM, Vaala WE, Barnett DC, Bain FT, Soboll Hussey G.Equine herpesvirus 1 (EHV-1) ubiquitously infects horses worldwide and causes respiratory disease, abortion, and equine herpesvirus myeloencephalopathy. Protection against EHV-1 disease is elusive due to establishment of latency and immune-modulatory features of the virus. These include the modulation of interferons, cytokines, chemokines, antigen presentation, and cellular immunity. Because the modulation of immunity likely occurs at the site of first infection-the respiratory epithelium, we hypothesized that the mucosal influenza vaccine Flu Avert I.N. (Flu Avert), which is known to stimulat...
Breuer J, Müller U, Locher L, Spallek A, Recknagel S, Uhlig A, Schusser GF.Proinflammatoric cytokines are released extracellularly during necrosis. These lead to inflammation and destruction of surrounding tissues. The aim of this study was to compare the number of viable, apoptotic and necrotic cells in the bronchoalveolar lavage fluid (BALF) of normal horses and horses with recurrent airway obstruction (RAO) and to determine if fluorescence microscopy is a reliable method for this examination. A group of six normal horses and a group of ten horses with RAO were examined. Samples were assessed using annexin-V and propidium iodide immunofluorescence assay and examine...
Slauson DO, Hahn FF.Advances in the understanding of human respiratory disease can come from careful clinical studies of the diseases as they occur in man, but such studies are naturally limited in terms of experimental manipulation. In the last 2 decades, an increasingly complex plethora of experimental respiratory disease models has been developed and utilized by investigators, but relatively less attention has been paid to the naturally occurring pulmonary diseases of animals as potential models. This paper is aimed at presenting selected examples of spontaneous pulmonary disease in animals that may serve as e...
Erichsen DF, Aviad AD, Schultz RH, Kennedy TJ.A field study of 239 horses was conducted to determine the efficacy and safety of clenbuterol HCl, a beta 2-adrenergic bronchodilator, when administered incrementally to effect in the treatment of chronic obstructive pulmonary disease (COPD). The severity of COPD (heaves) and response to treatment was determined by clinical evaluation; an overall 'heaveiness rating' (OHR) was assigned at each observation. The horses were treated orally b.i.d. with clenbuterol (as Ventipulmin Syrup), beginning with the lowest dosage of 0.8 micrograms/kg. On day 10 of treatment at the effective dose (0.8, 1.6, 2...
Bambra W, Daly JM, Kendall NR, Gardner DS, Brennan M, Kydd JH.Equine influenza virus is a highly contagious respiratory pathogen that causes pyrexia, anorexia, lethargy and coughing in immunologically naïve horses. Vaccines against equine influenza are available and vaccination is mandatory for horses that participate in affiliated competitions, but this group forms a small proportion of the total horse population. The aims of this study were to: i) identify the equine influenza vaccination rate as reported in 2016 by horse owners in the United Kingdom (UK); ii) examine the demographics of owners and horses which were associated with significantly lower...
Fernández-Távora L, Rico P, Martín S.This open clinical study was designed to investigate the occurrence of adverse reactions of specific immunotherapy (SIT) with horse dander and to recognize signs of efficacy regarding horse-induced cutaneous and respiratory symptoms. Methods: Twenty-four patients attending our Outpatient Clinic in Huelva (Spain) with horse-induced allergy were selected for receiving a standardized extract of horse dander (Alutard SQ). Results: Local and systemic reactions (five adverse reactions in four patients) were observed during the induction phase of treatment when administering the doses with the highes...
Chalmers HJ, Yeager AE, Cheetham J, Ducharme N.Recurrent laryngeal neuropathy (RLN) is the most common cause of laryngeal hemiplegia in horses and causes neurogenic atrophy of the intrinsic laryngeal muscles, including the cricoarytenoideus lateralis muscle. Recurrent laryngeal neuropathy results in paresis to paralysis of the vocal fold and arytenoid cartilage, which limits performance through respiratory compromise. Ultrasound has previously been reported to be a useful diagnostic technique in horses with RLN. In this report, the diagnostic sensitivity of subjective and quantitative laryngeal ultrasonography was evaluated in 154 horses p...
Dixon PM, Railton DI, McGorum BC.The majority of 270 adult horses with chronic pulmonary diseases had excessive volumes of respiratory secretions (RS) present in their trachea, elevated tracheal RS neutrophil ratios and lowered arterial oxygen partial pressures. Some control horses, had inexplicably elevated trachael RS neutrophil ratios. Only the chronic obstructive pulmonary disease (COPD) affected group had significantly elevated bronchoalveolar lavage fluid (BALF) neutrophil ratios. Maximal intrapleural pressure changes (max dPpl) were raised in 48% of COPD cases and rarely with other pulmonary disorders. Arterial pH or c...
Davis E, Rush BR, Herr LG, Ewert KM.Successful clinical management of bacterial pneumonia in horses depends on the administration of an appropriate antimicrobial agent at an adequate dosage and frequency, given by the correct route of administration for an adequate duration. Empiric antimicrobial therapy should be based on the clinician's experience and current veterinary literature. Based on the frequency of Gram-positive bacterial pathogens isolated from horses with bacterial pneumonia, every effort should be made to provide antimicrobial coverage for this class of pathogens. Gram-negative pathogens may co-exist; therefore, br...
General anaesthesia in horses is associated with elevated mortality rate in subjects suffering of heaves. Target-controlled infusion (TCI) of sedative-hypnotic medications and opioids represents a total intravenous anaesthesia (TIVA) method validated in veterinary medicine. Since there are no data concerning the impact of these classes of drugs in inducing bronchial hyperresponsiveness (BHR) in horses, the aim of this study was to investigate the effect propofol and remifentanil on the contractile response of equine airway smooth muscle. The influence of propofol and remifentanil on the contra...
Coleman MC, Blodgett GP, Bevevino KE, Ivanek R, Cummings KJ, Carter GK, Cohen ND.The occurrence of Rhodococcus equi at farms varies, with disease occurring endemically at some farms, but only sporadically, or not at all at other farms. Only some foals residing on endemic farms develop clinical signs of disease. Limited evidence is available regarding foal-level risk factors for the development of R. equi pneumonia. The purpose of this study was to identify foal-level risk factors associated with the development of R. equi pneumonia among foals at a large breeding farm in Texas with a recurrent problem of R. equi pneumonia. A retrospective cohort study was conducted usin...
Slowikowska M, Bajzert J, Miller J, Stefaniak T, Niedzwiedz A.Non-invasive diagnostic biomarkers of equine asthma syndrome (EAS) from blood or urine are sought. The aim of this study was to assess the absorbance of circulating immune complexes (CICs) during the exacerbation, remission, and treatment of an asthma episode and assess the potential usefulness of CIC levels in the diagnosis and monitoring of the disease. The control group, asthma group, and treated asthma group each contained six horses. Following an initial examination and group classification, the horses were kept in a dusty environment for seven days and then moved to an asthma-friendly en...
Fjordbakk CT, Strand E, Hanche-Olsen S.To test the hypothesis that in bilateral dynamic laryngeal collapse associated with poll flexion, vocal fold collapse (VFC) is the initial abnormal event that induces further laryngeal collapse, and that racing performance would therefore be substantially improved after bilateral ventriculocordectomy in affected individuals. Methods: Retrospective study. Methods: Twenty-six horses. Methods: Medical records (1998-2006) of harness racehorses admitted for high-speed treadmill videoendoscopy (HSTV) that had bilateral dynamic laryngeal collapse associated with poll flexion were reviewed. Race recor...
Sandersen C, Bienzle D, Cerri S, Franck T, Derochette S, Neven P, Mouytis-Mickalad A, Serteyn D.Horses commonly suffer from chronic respiratory disease and are also used in large animal models of spontaneous or induced airway inflammation. The anti-inflammatory properties of curcumin are largely described but its low bioavailability precludes its clinical use. NDS27, a lysin salt of curcumin incorporated in beta-cyclodextrine, has high bioavailability and can be administered by inhalation. The aim of this study was to investigate the effects of inhaled NDS27 on inflammatory cytokines and proteins in the broncho-alveolar lavage fluid using a model of neutrophilic airway inflammation. Meth...
Airaksinen S, Heiskanen ML, Heinonen-Tanski H, Laitinen J, Laitinen S, Linnainmaa M, Rautiala S.Respiratory exposure to organic dust induces chronic pulmonary diseases both in farmers and horses. The aim of this study was to examine the variation of dustiness and hygiene quality of peat moss bedding. Materials studied were weakly decomposed sphagnum peat (A), weakly decomposed sphagnum peat warmed up in storage (> 30 degrees C) (B) and two more decomposed few-flowered sedge peats (C and D). The geometric mean of mesophilic fungi, thermotolerant fungi and thermophilic actinomycetes were determined from the material. Samples of inhalable dust and endotoxins were collected with IOM samplers...
Szöke MO, Blais D, Cuvelliez SG, Lavoie JP.To evaluate the cardiovascular and respiratory effects of buprenorphine administered intravenously in clinically normal horses and horses with chronic obstructive pulmonary disease (COPD). Methods: 5 clinically normal horses and 5 horses with COPD that were in partial clinical remission (period A) or were having an acute attack of airway obstruction (period B). Methods: Pulmonary function testing, arterial blood gas analysis, and arterial blood pressure measurements were performed before and after a single intravenous bolus of buprenorphine (3 microg/kg of body weight). Respiratory rate (f), t...
Barton AK, Pelli A, Rieger M, Gehlen H.Procalcitonin (PCT), a precursor protein of the hormone calcitonin, is a sensitive inflammatory marker in human medicine, which is primarily used for diagnosis of bacterial sepsis, but is also useful in diagnosis of exacerbation of asthma and COPD. In this study, PCT was evaluated as a potential biomarker for different chronic pneumopathies in the horse using an equine specific ELISA in comparison to established clinical markers and different interleukins. Sixty-four horses were classified as free of respiratory disease, recurrent airway obstruction (RAO), inflammatory airway disease (IAD) or ...
Clark-Price SC, Cox JH, Bartoe JT, Davis EG.A 6-month-old male Quarter Horse was evaluated for chronic respiratory tract disease. Diagnostic investigations revealed pulmonary inflammation; Pneumocystis carinii was detected within macrophages. Lymphocyte subpopulation phenotyping and immunoglobulin concentration analysis were performed and results suggested immune suppression. Trimethoprim-sulfamethoxazole administration was initiated; the colt was discharged but was reexamined 8 days later because of profuse diarrhea and endotoxemia. Bacterial culture of feces recovered Salmonella spp resistant to trimethoprim-sulfamethoxazole, and a di...
Boyle AG, Martin BB, Davidson EJ, Durando MM, Birks EK.Dynamic pharyngeal collapse (PC) is a condition seen in racehorses that can be career-ending. Objective: To characterise and grade PC and describe the effects of PC on athletic performance. Methods: Medical records were reviewed for 828 horses, of which 49 (6%) records were identified as horses with a primary diagnosis of PC. Tapes of video-endoscopy of the pharynx during exercise were reviewed. Each video recording was assigned a grade (0-4) reflecting the degree of PC and a classification for severity of upper airway obstruction. Earnings per race prior to diagnosis of PC were compared to ea...
