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.
Back H, Kendall A, Grandón R, Ullman K, Treiberg-Berndtsson L, Ståhl K, Pringle J.A standardbred gelding with a history of 10 days pyrexia and lethargy was referred to the Equine Hospital at the Swedish University of Agricultural Sciences in Uppsala, Sweden.The horse had tachypnea with increased respiratory effort and was in thin body condition. Laboratory findings included leukocytosis, hyperfibrinogenemia and hypoxemia. Thoracic radiographs showed signs of pneumonia with a multifocal nodular pattern, which in combination with lung biopsy findings indicated Equine Multinodular Pulmonary Fibrosis (EMPF). EMPF is a recently described disease in adult horses with clinical s...
Hansson I, Johansson KE, Persson M, Riihimäki M.Nicoletella semolina, a member of the family Pasteurellaceae, can be isolated from the airways of horses with respiratory disorders. However, its role as a potential or opportunistic pathogen is not clear nor is its presence as part of the normal flora. We therefore investigated the presence and bacterial load of N. semolina in healthy and diseased horses. Samples from a healthy control group were compared with samples from the routine analysis of horses with a clinical history of respiratory disorders. A total of 1770 nose swabs and 1132 tracheal aspirate samples were analysed and subjected t...
Botha CJ, Lewis A, du Plessis EC, Clift SJ, Williams MC.Twenty-eight horses in southern Mozambique died after exhibiting severe respiratory distress. At necropsy, the overinflated lungs did not collapse, had prominent rib impressions, and were fibrotic and emphysematous. Microscopically, prominent proliferation of nonciliated epithelial (Clara) cells in the terminal bronchioles and pulmonary fibrosis were observed, indicative of chronic pneumotoxicity. Transmission electron microscopy demonstrated hyperplasia, desquamation, and apical bulging of Clara cells into the bronchiolar lumen. The outbreak was attributed to ingestion of Crotalaria dura J.M....
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...
Libardoni F, Vielmo A, Farias L, Matter LB, Pötter L, Spilki FR, de Vargas AC.Strangles is the main upper respiratory tract disease of horses. There are currently no studies on the changes in alleles of the M protein gene (seM) in Brazilian isolates of Streptococcus equi ssp. equi (S. equi). This study aimed to analyze and differentiate molecularly S. equi isolates from equine clinical specimens from southern Brazil, between 1994 and 2010. seM alleles were analyzed in 47 isolates of S. equi obtained from clinical cases of strangles (15 Thoroughbred horses, 29 Crioulo breed horses and three Brasileiro de Hipismo--BH). seM alleles characterization was performed by compari...
Couetil L, Hammer J, Miskovic Feutz M, Nogradi N, Perez-Moreno C, Ivester K.Equine recurrent airway obstruction (RAO) is characterized by airway inflammation, bronchoconstriction, and increased mucus production in the airways. Anticholinergic drugs like atropine induce bronchodilatation and rapid improvement in lung function. N-butylscopolammonium bromide (NBB) is an anticholinergic drug used to relieve spasmodic colic in horses, but its effect on airway smooth muscle is unknown. Objective: To evaluate the effect of NBB on clinical signs and lung function of RAO-affected horses. Methods: Nine horses diagnosed with RAO. Methods: Double-blind, placebo-controlled, random...
Moran G, Folch H, Henriquez C, Ortloff A, Barria M.Reaginic antibodies (IgE and some IgG subclasses) and mast cells play important roles in the induction of type I immediate hypersensitivity reactions. These antibodies bind through their Fc fragment to high affinity receptors (FcεRI) present in the membrane of mast cells and basophils. The cross-linking of the receptor initiates a coordinated sequence of biochemical and morphological events that results in exocytosis of secretory granules containing pre-formed inflammatory mediators, secretion of newly formed lipid mediators, and secretion of cytokines. Previously, several studies have invest...
Azab W, El-Sheikh A.Equine herpesvirus 4 (EHV-4) is an important equine pathogen that causes respiratory tract disease among horses worldwide. Glycoprotein K (gK) homologues have been identified in several alphaherpesviruses as a major player in virus entry, replication, and spread. In the present study, EHV-4 gK-deletion mutant has been generated by using bacterial artificial chromosome technology and Red mutagenesis to investigate the role of gK in EHV-4 replication. Our findings reported here show that gK is essential for virus replication in vitro and that the gK-negative strain was not able to be reconstitut...
Bidaud P, Hébert L, Barbey C, Appourchaux AC, Torelli R, Sanguinetti M, Laugier C, Petry S.Rhodococcus equi is one of the most widespread causes of disease in foals aged from 1 to 6 months. R. equi possesses antioxidant defense mechanisms to protect it from reactive oxygen metabolites such as hydrogen peroxide (H(2)O(2)) generated during the respiratory burst of phagocytic cells. These defense mechanisms include enzymes such as catalase, which detoxify hydrogen peroxide. Recently, an analysis of the R. equi 103 genome sequence revealed the presence of four potential catalase genes. We first constructed ΔkatA-, ΔkatB-, ΔkatC-and ΔkatD-deficient mutants to study the ability of R. ...
McGorum BC, Nicholas DR, Foster AP, Shaw DJ, Pirie RS.Bronchodilators are frequently used to attenuate airway obstruction in equine heaves (or recurrent airway obstruction). This study evaluated the selective (M(3) and M(1)) muscarinic antagonist revatropate, which offers potential advantages over non-specific antimuscarinic agents such as ipratropium. Protocol 1 assessed the response to inhaled revatropate (1, 2 and 7 mg) using a blinded, negative (inhaled saline) and positive (inhaled ipratropium bromide; 0.3, 0.7 and 2mg) controlled, dose escalation study, with six heaves horses. The lowest doses of revatropate and ipratropium induced a rapid ...
Lu Z, Timoney PJ, White J, Balasuriya UB.Equine rhinitis viruses A and B (ERAV and ERBV) are common equine respiratory viruses belonging to the family Picornaviridae. Sero-surveillance studies have shown that these two viral infections are prevalent in many countries. Currently, the diagnosis of ERAV and ERBV infections in horses is mainly based on virus isolation (VI). However, the sensitivity of VI testing varies between laboratories due to inefficient viral growth in cell culture and lack of cytopathic effect. Therefore, the objective of this study was to develop molecular diagnostic assays (real-time RT-PCR [rRT-PCR] and conventi...
Russold E, Ambrisko TD, Schramel JP, Auer U, Van Den Hoven R, Moens YP.To compare tidal volume estimations obtained from Respiratory Ultrasonic Plethysmography (RUP) with simultaneous spirometric measurements in anaesthetized, mechanically ventilated horses. Methods: Prospective randomized experimental study. Methods: Five experimental horses. Methods: Five horses were anaesthetized twice (1 week apart) in random order in lateral and in dorsal recumbency. Nine ventilation modes (treatments) were scheduled in random order (each lasting 4 minutes) applying combinations of different tidal volumes (8, 10, 12 mL kg(-1)) and positive end-expiratory pressures (PEEP) (0,...
Youssef MA, El-Khodery SA, Ibrahim HM.The aim of the present study was to evaluate the oxidative stress level and antioxidant trace elements status associated with lower airway disease in draft horses. For this purpose, venous blood samples were obtained from draft horses exhibiting signs of lower respiratory tract disorders (n = 83) and from control group (n = 20). Serum trace elements including selenium (Se), copper (Cu), zinc (Zn), manganese (Mn), and iron (Fe) were assayed. Serum malondialdehyde (MDA) and low-density lipoprotein (LDL) levels as well as plasma hydrogen peroxides (H₂O₂) concentration and activity of ...
Muranaka M, Yamanaka T, Katayama Y, Niwa H, Oku K, Matsumura T, Oyamada T.To investigate the pathology of equine influenza, necropsy of 7 horses experimentally infected with equine influenza A virus (EIV) subtype H3N8 was conducted on post-infection days (PID) 2, 3, 7, and 14. Histopathologically, rhinitis or tracheitis including epithelial degeneration or necrosis with loss of ciliated epithelia and a reduction in goblet cell numbers, was observed in the respiratory tracts on PIDs 2 and 3. Epithelial hyperplasia or squamous metaplasia and suppurative bronchopneumonia with proliferation of type II pneumocytes were observed on PIDs 7 and 14. Viral antigen was detecte...
Tsuchiya T, Hobo S, Endo Y, Narita S, Sakamoto K.To evaluate effects of a single dose of enrofloxacin (5 mg/kg, IV) on body temperature and tracheobronchial neutrophil count in healthy Thoroughbreds premedicated with interferon-α and undergoing long-distance transportation. Methods: 32 healthy Thoroughbreds. Methods: All horses received interferon-α (0.5 U/kg, sublingually, q 24 h) as an immunologic stimulant for 2 days before transportation and on the day of transportation. Horses were randomly assigned to receive enrofloxacin (5 mg/kg, IV, once; enrofloxacin group) or saline (0.9% NaCl) solution (50 mL, IV, once; control group) ≤ 1 hou...
Giguère S, Roberts GD.Our objective was to characterize the association between types of radiographic findings and outcome in foals with pneumonia caused by Rhodococcus equi. Admission lateral thoracic radiographs of 62 foals with culture-confirmed R. equi pneumonia were reviewed retrospectively. A scoring system was developed to individually assess the severity of alveolar pattern, interstitial pattern, tracheobronchial lymphadenopathy, pleural effusion, and the number of nodular opacities and cavitary lesions. Individual scores were added to obtain a total radiographic score ranging from 0 (normal) to 22. Forty-t...
Liccardi G, Emenius G, Merritt AS, Salzillo A, D'Amato M, D'Amato G.Most studies on the sensitization to horse allergens in populations without professional exposure have been carried out in geographical areas where the rate of horse ownership is high and horse riding is popular. Very few studies have been carried out in populations living in large urban areas. This gap in the literature probably reflects the widespread view that prevalence of horse-related allergy is low in urban populations because the latter are not regularly exposed to horses. On the contrary, we suggest that urban areas constitute a model useful to study potential modalities of exposure a...
Leclere M, Lavoie-Lamoureux A, Joubert P, Relave F, Setlakwe EL, Beauchamp G, Couture C, Martin JG, Lavoie JP.Recent studies suggest that airway smooth muscle remodeling is an early event in the course of asthma. Little is known of the effects of long-term antigen avoidance and inhaled corticosteroids on chronically established airway remodeling. We sought to measure the effects of inhaled corticosteroids and antigen avoidance on airway remodeling in the peripheral airways of horses with heaves, a naturally occurring asthma-like disease. Heaves-affected adult horses with ongoing airway inflammation and bronchoconstriction were treated with fluticasone propionate (with and without concurrent antigen av...
Rosanowski SM, Rogers CW, Cogger N, Benschop J, Stevenson MA.A survey was conducted to investigate biosecurity practices on non-commercial horse properties, to describe the number of visits by horse professionals and any protocols that visitors were required to follow before interacting with resident horses. Data were collected in November 2009 during a cross-sectional study of non-commercial horse properties, in New Zealand, selected using generalised random-tessellated stratified design and a self-administered postal questionnaire. Data were described and the associations between property-level factors and biosecurity practices were analysed using log...
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...
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 ...
Toussaint M, Fievez L, Desmet CJ, Pirottin D, Farnir F, Bureau F, Lekeux P.Recurrent airway obstruction (RAO, also known as equine heaves) is an inflammatory condition caused by exposure of susceptible horses to organic dusts in hay. The immunological processes responsible for the development and the persistence of airway inflammation are still largely unknown. Hypoxia-inducible factor (Hif) is mainly known as a major regulator of energy homeostasis and cellular adaptation to hypoxia. More recently however, Hif also emerged as an essential regulator of innate immune responses. Here, we aimed at investigating the potential involvement of Hif1-α in myeloid cells in ho...
Burgess HJ, Lockerbie BP, Czerwinski S, Scott M.A 12-year-old female Argentinean Warmblood mare was evaluated because of respiratory noise. The horse resided in Calgary, Alberta, Canada, but had been imported from Argentina 28 months prior to presentation. Endoscopy of the upper respiratory tract revealed a single polypoid mass on the left arytenoid. The mass was surgically excised and was diagnosed histologically as rhinosporidiosis. Polymerase chain reaction and DNA sequencing were used to confirm the etiological agent. Four weeks postoperatively, endoscopy was repeated, revealing recurrence of the original lesion with multiple additional...
Marqués FJ, Hehenberger E, Dickinson R, Wojnarowicz C, Lohmann K.A 9-year-old, 1494-lb (679-kg) Quarter horse gelding in good body condition was admitted to the Veterinary Teaching Hospital, Western College of Veterinary Medicine (WCVM), University of Saskatchewan, for evaluation and treatment of acute respiratory distress. On a trail ride 26 days before presentation, the gelding had been exposed to a horse with clinical signs of an upper respiratory tract infection. The gelding performed well on the trail ride but, 4 days later, developed a mild swelling in the retropharyngeal area and a slight bilateral mucoid nasal discharge. The gelding was examined at ...
Venugopal C, Mariappan N, Holmes E, Kearney M, Beadle R.To determine and compare the reactive oxygen and nitrogen species (ROS and RNS) in pulmonary tissues of horses affected with recurrent airway obstruction (RAO) and clinically healthy horses, and to evaluate the effectiveness of potential therapeutic agents in reducing ROS and RNS in the tissues of these horses. Objective: We hypothesised that RAO-affected horses would have high levels of reactive species and that the test agents would reduce them. The objectives were as follows: 1) to determine the level of ROS and RNS in pulmonary tissues (bronchial and arterial rings) of RAO-affected and cli...
Lyashchenko KP, Greenwald R, Esfandiari J, Lecu A, Waters WR, Posthaus H, Bodmer T, Janssens JP, Aloisio F, Graubner C, Grosclaude E, Piersigilli A....A case of pulmonary tuberculosis caused by Mycobacterium tuberculosis was diagnosed in a horse. Clinical evaluation performed prior to euthanasia did not suggest tuberculosis, but postmortem examination provided pathological and bacteriological evidence of mycobacteriosis. In the lungs, multiple tuberculoid granulomas communicating with the bronchiolar lumen, pleural effusion, and a granulomatous lymphadenitis involving mediastinal and tracheobronchial lymph nodes were found. Serologic response to M. tuberculosis antigens was detected in the infected horse, but not in the group of 42 potential...
Gryspeerdt AC, Vandekerckhove AP, Baghi HB, Van de Walle GR, Nauwynck HJ.Equine herpes virus (EHV)-1 replicates in the epithelial cells of the upper respiratory tract and reaches the lamina propria and bloodstream in infected mononuclear cells. This study evaluated expression of the late viral proteins gB, gC, gD and gM in respiratory epithelial and mononuclear cells using: (1) epithelial-like rabbit kidney cells and peripheral blood mononuclear cells infected with EHV-1 in vitro; (2) an equine ex vivo nasal explant system; and (3) nasal mucosa tissue of ponies infected in vivo. The viral proteins were expressed in all late-infected epithelial cells, whereas expres...
Zhang XY, Zhu FX, Olszewski MA, Robinson NE.The beta 2-agonists currently used as bronchodilators are racemic mixtures of R- and S-enantiomers. In the present study, we examined the effects of enantiomers of the beta 2-agonists albuterol and formoterol on acetylcholine (ACh) release from equine trachealis parasympathetic nerves. ACh release was evoked by electrical field stimulation (20 V, 0.5 ms, 0.5 Hz) and measured by high-performance liquid chromatography coupled with electrochemical detection. We also tested the effects of enantiomers of albuterol and formoterol on equine tracheal smooth muscle (TSM) contraction in response to exog...
Lee K, Pusterla N, Barnum SM, Lee DH, Martínez-López B.Equine influenza virus (EIV) is a major infectious pathogen causing significant respiratory signs in equids worldwide. Voluntary surveillances in the United States recently reported EIV detection in horses with respiratory signs even with adequate vaccine protocols and biosecurity programs and posed a concern about suboptimal effectiveness of EIV vaccine in the United States. This study aims to determine the genetic characteristics of 58 field EIV H3N8 strains in the United States from 2012 to 2017 using the phylogenetic analysis based on the haemagglutinin (HA) gene. Amino acid substitution a...
Schlusselhuber M, Guldbech K, Sevin C, Leippe M, Petry S, Grötzinger J, Giguère S, Cauchard J.The equine antimicrobial peptide eCATH1 previously has been shown to have in vitro activity against antibiotic-susceptible reference strains of Rhodococcus equi and common respiratory bacterial pathogens of foals. Interestingly, eCATH1 was also found to be effective in the treatment of R. equi infection induced in mice. The aim of this study was to assess the in vitro activity of eCATH1 against equine isolates of Gram-negative (Escherichia coli, Salmonella enterica, Klebsiella pneumoniae and Pseudomonas spp.) and Gram-positive (R. equi, Staphylococcus aureus) bacteria resistant to multiple cla...
Lavoie JP, Phan ST, Blais D.To evaluate the effects of detomidine and butorphanol in combination on respiratory function in horses and to determine whether these effects are more severe in horses with pre-existing respiratory dysfunction, Methods: Pulmonary function testing and arterial blood gas analyses were performed before and after administration of a combination of detomidine (10 micrograms/kg of body weight, i.v.) and butorphanol (20 micrograms/kg, i.v.). Methods: 5 horses with chronic obstructive pulmonary disease and 5 horses free of respiratory disease (controls). Methods: Flow rates were obtained from a pneumo...
Kelly PG, Reardon RJ, Johnston MS, Pollock PJ.Endoscopic examination of Thoroughbred (TB) yearlings is performed routinely to determine the suitability of horses for racing and to ensure that the conditions of sale are satisfied. However, previous research has demonstrated that resting endoscopic examination can be inaccurate in the diagnosis of functional pathology of the upper portion of the respiratory tract (URT). Objective: To investigate the feasibility of performing dynamic overground endoscopy in a group of TB yearlings and to compare the results of resting and dynamic endoscopic examination of the URT. Methods: Prospective cohort...
Cruz VC, Sommardahl CS, Chapman EA, Fry MM, Schumacher J.A 12-year-old 500-kg (1,100-lb) American Quarter Horse mare was evaluated because of chronic mucopurulent, bloody discharge from the left nostril, inspiratory dyspnea, and respiratory noise. Results: The horse had severe inspiratory dyspnea and stertorous respiration with no airflow from the left nostril. A temporary tracheostomy was performed. Endoscopy revealed a tan mass protruding from the left middle nasal meatus into the left common nasal meatus; it extended caudally into the nasopharynx and around the caudal edge of the nasal septum into the right nasal cavity. Radiographically, a soft ...
Jefcoat AM, Hotchkiss JA, Gerber V, Harkema JR, Basbaum CB, Robinson NE.Horses with the episodic asthmalike condition of recurrent airway obstruction (RAO) have bouts of inflammation and bronchoconstriction associated with indoor housing. To assess the potential differences in airway secretions between RAO-affected and control horses, methods to quantify mucus secretions were developed and applied to bronchoalveolar lavage fluid. The relative difference in the amount of mucin glycoproteins between control and RAO-affected horses was assessed with a carbohydrate side chain-specific monoclonal antibody (4E4) in an enzyme-linked immunosorbent assay and by carbohydrat...
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...
Mazan MR, Svatek J, Maranda L, Christiani D, Ghio A, Nadeau J, Hoffman AM.People working in cattle, swine and poultry barns have a higher prevalence of respiratory symptoms and decreased lung function. There is scant evidence regarding the respiratory health of humans working in horse barns, although it is well documented that stabled horses have a high prevalence of airway disease. Objective: To determine whether people spending time in horse barns have a higher prevalence of self-reported respiratory symptoms than non-exposed controls. Methods: A cross-sectional questionnaire study was conducted from May 2005 to January 2006 to investigate the prevalence of self-r...
Lavoie JP, Thompson D, Hamilton E, Debrue M, David F, Hickey G.It has been suggested that many of the beneficial effects of corticosteroids are mediated through mitogen-activated protein kinase (MAPK) p38 inhibition. Objective: To investigate the efficacy of the MAPK p38 inhibitor compound MRL-EQ1 to either prevent (Phase 1) or treat (Phase 2) recurrent airway obstruction (RAO) in horses. Methods: MRL-EQ1 was administered i.v. at a dosage of 0.75-1.5 mg/kg bwt q. 12 h. In Phase 1, susceptible horses in clinical remission were divided into 2 groups (n = 5/group), based on historical values of respiratory mechanics. All horses were entered in the study in p...
Zhu Y, Chen S, Yi Z, Holyoak R, Wang T, Ding Z, Li J. subsp. equi () is the pathogen causing strangles, a highly infectious disease that can affect equids including donkeys of all ages. It can persistently colonize the upper respiratory tract of animals asymptomatically for years, which serves as a source of infection. Several strangles outbreaks have been reported in the donkey industry in China in the last few years and pose a great threat to health, production, and the welfare of donkeys. Nasopharyngeal swab samples for culture and PCR are used widely in strangles diagnosis. Additionally, microbiomes within and on the body are essential to ho...
Erickson BK, Seaman J, Kubo K, Hiraga A, Kai M, Yamaya Y, Wagner PD.Previous work has shown that replacing N2 in air with He at the same inspired O2 fraction reduces the exercise-induced alveolar-arterial PO2 difference (AaPO2) in horses but has provided no mechanism explaining this effect. We sought to distinguish among possible causes by using the multiple inert gas elimination technique. Six horses were studied on a high-speed treadmill while they breathed either ambient air or normoxic He-O2. O2 uptake reached 138.0 ml.min-1.kg-1 and was not affected by He-O2. Temperature-corrected arterial PO2 was 76.7 Torr (air) and 86.9 Torr (He-O2) (P < 0.01). Corre...
Gilkerson J, Jorm LR, Love DN, Lawrence GL, Whalley JM.Equid herpesvirus-4 (EHV-4) was detected in nasal swabs taken from foals using a PCR based test and this information used to study the epidemiology of EHV-4 disease on three Australian Thoroughbred stud farms in NSW in 1992. There was a very high level of agreement (kappa value of 0.84) between the PCR results and virus isolation using cell culture techniques. There was a strong seasonal distribution of EHV-4 shedding. Twenty-five of 26 positive samples were collected in January and March with the remaining positive sample collected in February. Foals with clinical signs of upper respiratory t...
Pusterla N, James K, Mapes S, Bain F.Due to the inconsistent development of enteric signs associated with ECoV infection in adult horses, many practitioners collect nasal secretions rather than feces for the molecular diagnostic work-up of such horses. ECoV infection should be considered in horses presenting with acute onset of fever, especially when nasal discharge is absent as one of the cardinal clinical sign. A total of 277 adult horses with acute onset of fever were enrolled in this study. Feces were tested for ECoV and nasal secretions for common respiratory pathogens (equine herpesvirus (EHV)-1, EHV-4, equine influenza vir...
Volokhov DV, Gao Y, Davidson MK, Chizhikov VE.We describe two novel species of Acholeplasma sp. strain N93 and Mycoplasma sp. strain LR5794 which were isolated from the nasopharynx of a horse from the United Kingdom and from the oral cavity of a North American raccoon from Canada, respectively. These strains were phenotypically and genetically characterized and compared to other established Mycoplasma and Acholeplasma species. Both strains are facultative anaerobes, resistant to penicillin, and produce acid from glucose but do not hydrolyze arginine and urea. Both strains grew well in microaerophilic and anaerobic atmospheric conditions a...
Otzdorff C, Beckmann J, Goehring LS.(1) Background: Equine arteritis virus (EAV) infection causes reproductive losses and systemic vasculitis in susceptible equidae. The intact male becomes the virus' reservoir upon EAV infection, as it causes a chronic-persistent infection of the accessory sex glands. Infected semen is the main source of virus transmission. (2) Here, we describe acute EAV infection and spread in a stallion population after introduction of new members to the group. (3) Conclusions: acute clinical signs, acute phase detection of antigen via (PCR) nasal swabs or (EDTA) blood, and seroconversion support the idea of...
Duz M, Whittaker AG, Love S, Parkin TD, Hughes KJ.Measurement of hydrogen peroxide (H(2)O(2)) concentration and pH in exhaled breath condensate (EBC) is useful for detection and monitoring of asthma in humans. In contrast, limited information on the use of these parameters for the investigation of lower airway inflammation (LAI) is available for horses. Aims of the current study were to investigate the intra- and inter-day variations of EBC H(2)O(2) concentration and pH in horses and establish any relationship(s) with LAI. Both intra- and inter-day variability of EBC H(2)O(2) concentration were large, while those of pH were small. No signific...
Bianchi MV, Mello LS, Ribeiro PR, Wentz MF, Stolf AS, Lopes BC, de Andrade CP, Snel GGM, Sonne L, Driemeier D, Pavarini SP.We document the causes and pathological findings in 50 cases of equine pneumonia and pleuritis in Southern Brazil. Suppurative (17/50), pyogranulomatous (14/50), aspiration (5/50), mycotic (4/50), bronchointerstitial (3/50), embolic (3/50) and eosinophilic granulomatous pneumonia (1/50) and pleuritis (3/50) were the main conditions identified. Streptococcus spp. were identified in 11 cases of suppurative pneumonia. Suppurative pneumonia was further divided into acute (8/17), subacute (6/17) and chronic (3/17) based on the morphological pattern of lesions. Rhodococcus equi was identified in all...
BMC research notesSeptember 24, 2015
Volume 8 471 doi: 10.1186/s13104-015-1441-0
Boukharta M, Azlmat S, Elharrak M, Ennaji MM.Three equine influenza viruses, A/equine/Nador/1/1997(H3N8), A/equine/Essaouira/2/2004(H3N8), and A/equine/Essaouira/3/2004(H3N8), were isolated from different Equidae during local respiratory disease outbreaks in Morocco in 1997 and 2004. Their non-structural (NS) genes were amplified and sequenced. Results: The results show high homology of NS nucleotide sequences of A/equine/Nador/1/1997 with European strains (i.e., A/equine/newmarket/2/93 and A/equine/Grobois/1/1998) and clustered into the European lineage. However, NS gene of A/equine/Essaouira/2/2004(H3N8) and A/equine/Essaouira/3/2004(H...
Ramzan PH, Parkin TD, Shepherd MC.There has been much research directed at potential causative agents and the epidemiology of lower respiratory tract disease (LRTD), but few reports of the clinical progression and outcome. Objective: To define clinical features of LRTD in racehorses, including association with age and average duration of disease, through the analysis of endoscopic data. Methods: A retrospective analysis of records from a single training yard of endoscopic examinations undertaken over a 2-year period was performed. Horses were subjected to regular endoscopic examination for a variety of reasons, and all horses ...
Pusterla N, Leutenegger CM, Barnum SM, Byrne BA.In recent years, molecular approaches have been able to characterise the viability of equine upper respiratory tract pathogens using absolute molecular quantitation as well as detection of transcripts for virulence genes. Objective: The objective of this study was to investigate molecular surrogates for S. equi subspecies equi (S. equi) viability in biological samples from horses with strangles. Methods: Retrospective cross-sectional study. Methods: S. equi culture-positive and culture-negative upper airway secretions were assessed by qPCR at the genomic (gDNA) and complimentary DNA (cDNA) ...
Jean D, Vrins A, Lavoie JP.To determine temporal variations of pulmonary function in horses without respiratory tract disease (controls) and horses with chronic obstructive pulmonary disease (COPD) and determine whether reversibility of airway obstruction after environmental control can be predicted by response to atropine administration. Methods: 7 COPD-affected and 5 control horses. Methods: Pulmonary function testing was performed monthly during 3 consecutive months, daily for 5 consecutive days, and at 6-hour intervals for 24 hours before and after administration of atropine (0.02 mg/kg of body weight, i.v.) and aft...
du Preez S, Raidal SL, Doran GS, Prescott M, Hughes KJ.Exhaled breath condensate (EBC) analysis is a noninvasive method to assess the lower respiratory tract. In human subjects, EBC hydrogen peroxide (H O ), pH and leukotriene B (LTB ) are useful for detection and monitoring of inflammatory lung diseases, including asthma. Objective: To determine associations between EBC biomarkers and cytological and endoscopic definitions of lower airway inflammation (LAI) while controlling for sampling and environmental variables. Methods: Prospective, cross-sectional study. Methods: Clinical, endoscopic and airway cytological findings from 47 horses were compa...
Mitlehner W, Mitlehner HC, Niggemann B.To test the hypothesis that so called hypoallergenic horses (Curly horses) allow horse allergic riders to ride again, we investigated 40 horse allergic riders in a period of 37 months. We tested these patients (pts.) by skin prick test (SPT) with different non-curly and Curly horses and studied the riding hours and horse brushing by measurements of peak expiratory flow (PEF) and Tiffeneau tests (FEV1) as well as peak nasal inspiratory flow (PNIF) over 12 months. The results in 37/40 pts. showed no relevant reactions of the lower airways or nasal flow. Only in 3/40 patients an initial signific...
Bernardino P, James K, Barnum S, Corbin R, Wademan C, Pusterla N.Equine rhinitis B virus (ERBV) has been given little attention by practitioners compared to other respiratory viruses, mainly because of the lack of diagnostic modalities and association with clinical disease. The objective of the study was to determine the frequency of detection of ERBV in nasal secretions from 6568 horses with acute onset of respiratory signs. ERBV-positive qPCR results from nasal secretions submitted to a molecular diagnostic laboratory from 2013 to 2019 were reviewed. A total of 333 ERBV qPCR-positive samples (5.1%) were detected with increasing yearly frequency since the ...
Makrai L, Fodor L, Csivincsik A, Varga J, Senoner Z, Szabó B.The cultural, morphological, biochemical, serological characteristics and antibiotic susceptibility of 25 Rhodococcus equi strains isolated from lungs and lung abscesses of pneumonic foals and 5 R. equi strains isolated from immuno-compromised human patients were examined. All R. equi strains showed common cultural, morphological and biochemical characteristics both with conventional tests and on the basis of their enzyme profile. The R. equi strains examined were resistant to penicillins with the exception of ampicillin, to sulphamethazine and several strains also to sulphamethoxazole-trimeth...
Bolton T, Kuskie K, Halbert N, Chaffin K, Healy M, Lawhon S, Jackson A, Cohen N.Rhodococcus equi is an important pathogen of foals aged 1-6 months. Evidence exists that foals are exposed to a wide diversity of R. equi strains in their environment. However, limited data are available regarding the extent to which genotypic variation exists among isolates infecting individual foals. Therefore, electrophoresis of repetitive sequence-based polymerase chain reaction (rep-PCR) amplicons in an automated microfluidics chip format was used to genotype 9 virulent R. equi isolates obtained from distinct anatomic locations in a single foal. Four of the isolates were obtained from dif...
Kearns CF, McKeever KH.Clenbuterol is a beta(2)-agonist and potent selective bronchodilator that is used to treat bronchospasm in the horse. The drug is normally administered to horses orally as a syrup formulation. Once absorbed into the systemic circulation, clenbuterol has the potential to cause many side effects, including a repartitioning effect and major alterations in cardiac and skeletal muscle function. Recent studies have also reported that clenbuterol can affect bone and the immune, endocrine and reproductive systems. A great deal of information has been published on the beneficial effects of short term t...
Laing G, Christley R, Stringer A, Ashine T, Cian F, Aklilu N, Newton R, Radford A, Pinchbeck G.Respiratory disease is a common cause for presentation of working horses to clinics in Ethiopia and a priority concern for owners. Objective: To identify risk factors for and association of pathogens with respiratory signs in working horses. Methods: Unmatched case-control study. Methods: Cases were those animals recently coughing (last 7 days) or observed with coughing, nasal discharge or altered respiration at the time of examination. A physical exam and respiratory endoscopy were performed including a tracheal wash sample to detect the presence of pathogens and serology performed on blood....
Floyd E, Danks S, Comyn I, Mackenzie C, Marr CM.Respiratory disease is common in critically ill neonatal foals. Traditional oxygen therapy (TOT) with nasal insufflation of oxygen is often used to provide first-line respiratory support. Mechanical ventilation is used in foals which require a greater level of support but requires specialist expertise and can be associated with significant complications. Non-invasive ventilation (NIV) enables a greater level of respiratory support without the need for intubation. High flow oxygen therapy (HFOT) is a mode of NIV commonly used in human intensive care. Objective: To describe the use of HFOT in ho...
