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.
DITCHFIELD J, MACPHERSON LW.From outbreaks of upper respiratory infection of horses in the Toronto area between 1960 and 1963, several viruses have been isolated. The viruses, isolated in tissue cultures or eggs, include an equine strain of Myxovirus parainfluenzae 3; two strains of equine influenza virus, A/equi-1/Prague/56, and A/equi-2/Miami/63; equine rhinopneumonitis virus, and two newly recognized viruses of the horse, equine rhinoviruses. In addition serological evidence suggested a widespread infection with these viruses in the population under study. Because of the identical clinical picture seen and the complex...
PLUMMER G.Experiments involving the intranasal inoculation of monkeys, rabbits and guinea pigs with an equine respiratory virus were carried out. The animals were killed at various intervals after inoculation and attempts made to isolate virus in tissue culture from extracts of homogenized tissues and organs. All three species were susceptible, virus reproduction occurring in the respiratory tract and associated lymph glands. Of the three species virus was least readily isolated from the guinea pig tissues. There was a viraemia in monkeys and rabbits, but virus was less readily detected in the blood of ...
Gonzalez-Obando J, Jaimes-Dueñez J, Zuluaga-Cabrera A, Forero JE, Diaz A, Rojas-Arbeláez C, Ruiz-Saenz J.Equine influenza is a highly contagious disease caused by the equine influenza virus (EIV). The occurrence of EIV outbreaks in America is associated with low levels of vaccination coverage. In Colombia, no seroprevalence evaluation has been carried out to estimate the distribution of the virus within the country. Our aim was to perform a sero-epidemiological survey of equine influenza infections and to identify associated risk factors in horses from four departments of Colombia. Serological testing was carried out by using an ELISA for the detection of IgG antibodies against the influenza A vi...
Haase L, Winter J, Grummt S, Sedlmayr M, Sedlmayr B.Many people seek health-related information online, not only for themselves but also on behalf of others who cannot articulate their symptoms. This proxy information-seeking behavior is particularly relevant for animal owners, who must interpret their animals' symptoms without direct verbal feedback. While online health information-seeking in the context of one's own health is well-studied, the specific challenges of searching by proxy, especially for animal health information, remain largely unexplored. Unassigned: This study aimed to determine the specific information needs and search behavi...
Wenzel CJ, Mochal-King CA, Eddy AL, Bowser JE, Wills RW, Jumper WI, Claude A, Swiderski CE.The aim of this retrospective clinical study was to assess surgical duration and surgical and post-operative complications associated with Video-Assisted Thoracoscopic Surgery (VATS) and lung biopsy in horses with severe Equine Pasture Asthma (EPA) and paired control horses. Twelve horses (6 EPA-affected, 6 control) were sex, age and breed matched. Twenty-four thoracic surgeries were performed. Surgery of each matched pair (EPA-affected and healthy) was performed during asthma exacerbation (summer) and remission (winter). Surgical times were shorter with uncomplicated thoracoscopy (85 min) and...
Williams MR, Silverstone A, Burba DJ, McCarrel T, Schoonover MJ, Rudra P.To describe the prevalence of postrace airway abnormalities in a population of barrel racing horses competing in Oklahoma. Unassigned: A descriptive field study was conducted at a single event. Horses underwent resting endoscopy within 60 minutes of competition. Recordings were evaluated and numerical and/or binary scores assigned for pharyngeal lymphoid hyperplasia, recurrent laryngeal neuropathy, dorsal displacement of the soft palate, epiglottic entrapment, and exercise-induced pulmonary hemorrhage. Clients completed a questionnaire detailing the horse's medical history and run time. A line...
Calero IM, McKenzie EC, Johns JL.This report describes the diagnosis and successful management of a yearling filly with Coombs-positive anemia, thrombocytopenia, and fungal pneumonia. Diagnostic procedures, including thoracic ultrasonography and radiography, respiratory pathogen PCR testing, and evaluation of tracheal wash and bronchoalveolar lavage samples established multi-pathogen lower respiratory tract infection including a fungal agent. Orally administered voriconazole was a key component of treatment in this case to successfully eliminate fungal infection, alongside therapies for managing hematologic disease. This case...
Werner CA, Wimmer-Scherr CM, Schwarz BC.Equine laryngeal dysplasia (ELD) is the umbrella term for various malformations of laryngeal structures that arise from the 4th and 6th branchial arches during embryogenesis. The disease is rare and may be subclinical. In symptomatic patients with clinical signs, the clinical presentation is highly variable and is the result of functional limitations of the larynx as well as of the esophageal sphincter. The spectrum of signs may range from respiratory changes such as abnormal respiratory noise, coughing, and at times dyspnea all the way to poor performance, dysphagia, aerophagia, and colic. Th...
Andrade AC, Fonseca SMC, Silva Filho GB, Melo ET, Santos JRP, Frota MLSL, Duarte JMBS, Evêncio-Neto J, Brito LB, Lima TS, Wicpolt NS, Riet-Correa F....We report an outbreak of Crotalaria juncea intoxication in horses exhibiting progressive weight loss and respiratory distress in northeastern Brazil. Necropsy revealed firm, non-collapsed lungs with extensive interstitial fibrosis, bronchiolar epithelial hyperplasia with club cells proliferation, and marked pulmonary arterial remodeling. Hepatic lesions consisted primarily of centrilobular necrosis, probably resulting from hypoxic injury related to anemia and prolonged agonic death. Pasture inspection identified significant invasion by shrubs of C. juncea in various phenological stages.
Mahalingam-Dhingra A, Bedenice D, South A, Minuto J, Robins TJ, Trautwein V, Larkin M, Wagner B, Mazan MR.Corticosteroids are the main pharmacologic treatment for equine asthma (EA) but may have adverse effects in metabolically unstable horses. Recent pilot studies support the use of nebulized lidocaine as an alternative treatment option. Objective: Nebulized lidocaine will improve EA-associated clinical variables and airway inflammation. Methods: Twenty client-owned horses diagnosed with EA. Methods: Randomized, blinded, in-hospital study comparing 1 mg/kg preservative-free 4% lidocaine (n = 10) nebulized via Flexineb (twice daily for 7 doses) to 0.9% saline control (n = 10). Clinical examin...
Henderson AR, Valverde A, Côté N, Sanchez A, Arroyo LG, Gu Y, Johnson R.To compare cardiopulmonary variables and recovery scores in isoflurane-anesthetized horses undergoing arthroscopy using two different intravenous (IV) lidocaine constant rate infusions (CRIs; 50 or 100 μg kg minute) under intermittent positive pressure ventilation (IPPV) or spontaneous ventilation (SV). Methods: Prospective, randomized, clinical study. Methods: A group of 30 client-owned horses, 8-156 months old (range), with body masses of 280-550 kg. Methods: Anesthesia protocol consisted of xylazine, ketamine and diazepam, and maintenance with isoflurane and a CRI of dexmedetomidine. All g...
Nout-Lomas YS, Story MR.Equine head and neck disorders can present with a wide range of clinical manifestations, depending on the structures involved and disease process. Important components of the gastrointestinal, respiratory, ophthalmological, neurological, and musculoskeletal systems are contained within the head and neck, and clinical signs of disorders will result in expected clinical signs. However, clinical manifestations of disease are sometimes subtle, and when not recognized can lead to behavioral changes including undesired behaviors and poor sleep. Recognizing behavioral phenotypes of horses with proble...
Tyson KN, Couetil LL, Ivester KM, Murray L, Mukhopadhyay A, Marmolejo JF, Jannasch A.Nebulization of injectable dexamethasone sodium phosphate (DSP; 0.01 mg/kg) to horses with severe equine asthma (SEA) was previously found to be ineffective. Horses with SEA have marked bronchoconstriction that decreases peripheral lung deposition of nebulized drugs. Administration of a bronchodilator immediately before nebulizing dexamethasone may improve efficacy. Objective: Evaluate the therapeutic effects and optimal dose of nebulized DSP after nebulized albuterol in horses with SEA. Methods: Seven horses with SEA from a research herd. Methods: In this masked randomized crossover trial, h...
Dörsam K, Nischang V, Büttner K, Fey K, Werz O, Jordan PM.Equine asthma (EA) is a chronic inflammatory disease of the lower respiratory tract in horses, which is mainly triggered by dusty hay. EA is becoming increasingly acknowledged as a valuable animal model for studying human asthma. Research on the pathogenesis of EA has primarily focused on the associated cells and cytokines involved. However, the role of inflammation-related lipid mediators (LM) in the development and progression of equine asthma remains elusive. LMs are categorized into pro-inflammatory arachidonic acid (AA)-derived leukotrienes (LTs) and prostaglandins (PGs), as well as infla...
Raidal SL, van Diggelen M, Catanchin CSM, Lehmann HS, Quinn CT.Noninvasive ventilation (NIV) provides effective respiratory support in foals, but face masks are poorly tolerated and associated with hypercapnia. Bi-nasal prongs might be a more effective device interface in foals. Objective: To compare bi-nasal prongs and masks for NIV in foals with pharmacologically induced respiratory insufficiency. Methods: Six healthy foals. Methods: In a randomized cross-over study, sedated foals received NIV delivered by mask or bi-nasal prongs, with the treatment repeated using the alternative device interface after a 3-day rest period. After periods of spontaneous v...
Alves LSS, Hasuda AL, Giordano LGP, Frederico I, Dos Santos IH, Pereira PFV, Lisbôa JAN, Flaiban KKMDC.This study investigated isolation of equine neutrophils and the assessment of their antioxidant function using the nitroblue tetrazolium (NBT) reduction test, an indicator of reactive oxygen species (ROS) activation. The objective was to test the viability of neutrophils isolated from equine whole blood and their ability to undergo respiratory burst, comparing the results with whole blood. The hypothesis tested was that isolation of equine neutrophils allows for effective functional evaluation, even after isolation process, with no significant differences between whole blood and isolated cells...
Bannai H, Kambayashi Y, Kume K, Takebe N, Endo Y, Kawanishi N, Nemoto M, Tsujimura K.The endemic situation of respiratory disease caused by equine herpesvirus type-1 (EHV-1) and type-4 (EHV-4) was investigated in a training facility for Thoroughbred yearlings in Japan. Vaccination typically starts in mid-September or early October-only after all yearlings have arrived-leaving those introduced earlier unprotected. To bridge this immunity gap, a revised vaccination program that started earlier was implemented. In 2021-2022 and 2022-2023, yearlings were allocated to three groups according to their introduction dates. Each group received a live EHV-1 vaccine (Equi N Tect ERP, Niss...
Hopster K, Soares JHN, Levine D, Ortved K, Driessen B, Araos J.Flow-controlled expiration (FLEX) has been shown to significantly enhance oxygenation in horses under laboratory conditions. Objective: This study aims to corroborate these findings by evaluating the effects of FLEX on gas exchange in a randomised clinical trial involving a large population of clinical horses undergoing orthopaedic surgery. Methods: Prospective randomised clinical trial. Methods: A total of 406 healthy adult horses scheduled for elective orthopaedic procedures were recruited for this prospective clinical trial. Horses were randomly assigned to FLEX or VCV (volume-controlled ve...
Lendl L, Wirth C, Merle R, Barton AK.Mild-moderate equine asthma (MEA) is a very common but underdiagnosed pulmonary disease in horses, with mild cases not showing clinical respiratory signs. This study evaluates the influence of a standardized lunging exercise test (SLET) on bronchoalveolar lavage fluid (BALF) cytology in MEA horses. We hypothesized that SLET would increase the total nucleated cell count (TNCC) and/or percentages of inflammatory cells associated with EA. In a prospective, randomized, non-blinded, between-subjects study design of two independent groups, 39 horses (17 mild and 22 moderate) were included. They were...
Andrews KM, Berghaus LJ, Hart KA.Equine Asthma Syndrome (EAS) is a chronic inflammatory respiratory disease of adult horses. While dietary polyphenols have shown anti-inflammatory effects in human asthma, their use in equine asthma has not been studied. Objective: To evaluate the effects of a mixed polyphenol supplement on systemic and pulmonary inflammation, bronchoalveolar lavage (BAL) cytology, and clinical respiratory signs in healthy and asthmatic horses. We hypothesized that polyphenol supplementation would decrease systemic and pulmonary inflammation in both healthy and asthmatic horses and would improve BAL cytology a...
Berghaus LJ, Venner M, Helbig H, Hildebrandt D, Hart K.Rhodococcus equi causes pneumonia in young foals, but disease susceptibility and severity vary. Cortisol and vitamin D modulate immune responses and cytokine production during bacterial infection, and altered concentrations are associated with sepsis in neonatal foals. We hypothesised an age and disease effect on circulating steroid hormone concentrations in foals, and that differences in cytokines and steroid hormone concentrations would predict disease severity in pneumonic foals. Objective: To investigate circulating concentrations of various cytokines, cortisol and vitamin D as predictors ...
Čebulj-Kadunc N, Frangež R, Kruljc P.The aim of the study was to determine the fluctuations of selected physiological parameters in young Lipizzan stallions ( = 10) during the initial phase of their training as indicators of adaptation to a graded exercise load and stress exposure. For this purpose, four exercise tests (ExT) with lunging were carried out over a period of one year. Physiological parameters (gait speed, heart and respiratory rate (HR and RR), rectal and body surface temperature (RT and BST), and cortisol and lactate concentration (CORT and LAC)) were measured before and after training. In all ExT, gait speeds incre...
Bozzola C, Sala G, Stancari G, Ferrucci F, Zucca E.Exercise-Induced Pulmonary Hemorrhage (EIPH) results from alveolar capillary stress failure after strenuous exercise, leading to bleeding and pulmonary inflammation. Bronchoalveolar lavage fluid (BALF) cytology is considered the gold standard for the assessment of airway inflammation; however, it is often considered more invasive compared to tracheal wash (TW). It has been demonstrated that TW is a reliable diagnostic tool that may substitute BALF to diagnose and grade the severity of EIPH in racehorses; however, no information about airway inflammation in EIPH-affected horses has been reporte...
Kozłowska N, Borowska M, Jasiński T, Wierzbicka M, Domino M.In human medicine, computer-aided diagnosis (CAD) is increasingly employed for screening, identifying, and monitoring early endoscopic signs of various diseases. However, its potential-despite proven benefits in human healthcare-remains largely underexplored in equine veterinary medicine. This study aimed to quantify endoscopic signs of pharyngeal lymphoid hyperplasia (PLH) as digital data and to assess their effectiveness in CAD of PLH in comparison and in combination with clinical data reflecting respiratory tract disease. Endoscopic images of the pharynx were collected from 70 horses clinic...
Phillips NAI, Hackett ES.Respiratory surgery and procedures typically focus on conditions of the upper airway that restrict airflow at rest or exercise. This article focuses on respiratory anatomy and common surgeries of the trachea and larynx in horses. The trachea serves as the airway conduit from the larynx to the bronchi. A variety of upper airway disorders can lead to obstruction and in these instances, tracheotomy is typically utilized to bypass these obstructions and maintain airway patency. Emergency and permanent tracheotomy procedures are discussed. Other common upper airway operations, such as laryngotomy, ...
McLinden LA, Kemp-Symonds JG, Daly JM, Blanchard AM, Waller AS, Freeman SL.Infection with Streptococcus equi subspecies equi (S. equi) is characterised by acute disease, with about 10% of infected animals remaining persistently infected. Clinically, infection with S. equi cannot readily be distinguished from infection caused by other respiratory pathogens, including Streptococcus equi subspecies zooepidemicus (S. zooepidemicus), equine influenza virus, and equine herpes virus. Screening protocols, with appropriate quarantining facilities, are important to detect horses infected with S. equi and avoid strangles outbreaks. Virulent strains of S. zooepidemicus can also ...
Pınar O, Çelik Doğan C, Aktaran Bala D, Kumaş C, Mete A.Riding clubs face significant financial losses due to upper respiratory infections caused by Beta-hemolytic (β-hemolytic) streptococci, leading to strangles and related diseases that negatively impact the health and performance of horses. Our objective was to determine the relationship between these inflammatory cells, the presence of β-hemolytic streptococcal species, and the clinical symptoms exhibited by the horses. This study investigated the presence of β-hemolytic streptococcus in 133 tracheal lavage samples from horses exhibiting various clinical respiratory symptoms and quantified t...
Meiseberg LK, Mergani A, Delarocque J, Imker R, Köhn D, Wanes D, Bonilla MC, Veldhuizen EJA, von Köckritz-Blickwede M, Ohnesorge B, de Buhr N.Equine asthma (EA) is the most prevalent chronic lung disease in horses. Neutrophils are the main effector cells in severe EA. Neutrophil extracellular traps (NETs) have been described as contributors to severity in human asthma and chronic obstructive pulmonary disease. Thus, we aimed to investigate if NET-related factors in equine neutrophils, blood and bronchoalveolar lavage fluid (BALF) allow us to differentiate EA severities and to identify NET-related mechanistic insights in EA. We quantified NETs and NET-related factors in the blood and BALF of eight healthy horses and 18 horses with di...
Al Shehab G, Naji R, Alali F, Alali A, Allowaim A, Almohammed A, Aljasim D, Alkhalifah A, Alhammad YMA, Marzok M, Mohamad ZA, Almuhanna AH.The equine larynx can be affected by a variety of diseases that may interfere with upper respiratory tract patency. Laryngeal hemiplegia is a well-known disease in large-sized equine breeds and its occurrence in Arabian horses has not been thoroughly investigated. Unassigned: To endoscopically assess arytenoid movements in pure Arabian horses. Unassigned: A total number of 38 pure Arabian horses were examined. When the horse was unsedated, the laryngeal arytenoid movement was assessed using a laryngoscope, and a grading score was assigned accordingly. Unassigned: Evidence of laryngeal movement...
Jeong S, Bond S, Bayly W, Sole-Guitart A.To quantify the impact of experimentally induced dorsal nasopharyngeal collapse (NPC) on respiratory performance parameters and assess the efficacy of laser fenestration of the dorsal pharyngeal recess as a treatment option for experimentally induced NPC. Methods: Experimental interventional study. Methods: Six adult Standardbreds (one with naturally occurring disease). Methods: After an 8 week conditioning program, baseline parameters (V̇Omax, pharyngeal pressure, peak airflows, upper airway resistance) and dynamic endoscopy videos were collected in a high-speed treadmill test (T1). Dorsal N...
Barbosa B, Santi TF, Rodak AC, Nogara MF, Leite LMB, Weber SH, Niels C, Daros RR, Michelotto PV.The analysis of equine exhaled breath condensate (EBC) lacks standardized methodology, and current collection devices are often adapted for research. This study evaluates a novel horse-specific EBC collector and assesses the variability of EBC pH and hydrogen peroxide (HO) levels, exploring potential correlations with bronchoalveolar lavage (BAL) and tracheal wash (TW) cytology. Eleven healthy mixed-breed mares from a teaching herd, with no evidence of airway abnormalities, were included in this randomized observational study. The collection efficiency of the proposed device was assessed, and ...
Vainio KME, Määttänen MK, Mykkänen AK, Huupponen AK, Niinistö KE.Iatrogenic aspiration pneumonia is rarely reported in horses, with most cases involving lipoid pneumonia from accidental mineral oil administration. Objective: Our aim is to describe horses with iatrogenic aspiration, highlighting clinical findings, treatment, outcomes, and prognostic differences based on the aspirated material. Methods: Management of 6 horses treated at the University of Helsinki Equine hospital due to iatrogenic aspiration between 2018 and 2023 are reported. Results: Of the six horses, three survived, two of whom regained full athletic function. Survivors received water, or ...
