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.
Hospes R, Hospes BI, Reiss I, Bostedt H, Gortner L.In the following, we describe the isolation and sequencing of the equine surfactant protein A (Sp-A) as found in both the cDNA and the genomic DNA. We found a length of the cDNA sequence of 747 bp (base pairs), in translation into amino acids of 248. Compared with the known molecular biological facts about Sp-A in other species, the cDNA sequence obtained showed highest homology with that of sheep (85.01%). The genomic DNA of equine Sp-A, as in other species, includes three introns. There were no hints for the existence of two different Sp-A genes. These results should form the basis for a bet...
Davis E, Rush BR.Recurrent airway obstruction is a condition that affects some older horses maintained in confinement. Clinical signs range from exercise intolerance with occasional cough to dyspnea at rest. Bronchoalveolar lavage cytology is characterized by neutrophilic leukocytosis (15%-85%) and is recommended for making the diagnosis in horses with mild to moderate disease. Environmental management combined with periodic bronchodilator and antiinflammatory corticosteroid therapy yields the best prognosis for disease remission.
Törneke K, Ingvast-Larsson C, Boström A, Appelgren LE.The distribution of muscarinic receptors in equine airways was investigated using autoradiography. Frozen sections of tissue from six different levels in the bronchial tree, from the trachea to the distal bronchioles, were incubated in vitro with 1.5 nmol/L of the muscarinic receptor antagonist 1-[N-methyl-3H]scopolamine methyl chloride (3H-NMS). In addition, the subtype pattern of muscarinic receptors was investigated in equine tracheal smooth muscle using radioligand binding with methoctramine, tripinamidc, 4-DAMP-methiodide and pirenzipine as competitors against the binding of 1.3 nmol/L 3H...
Cable CS, Ducharme NG, Hackett RP, Erb HN, Mitchell LM, Soderholm LV.To investigate whether upper airway sounds of horses exercising with laryngeal hemiplegia and alar fold paralysis have distinct sound characteristics, compared with unaffected horses. Methods: 6 mature horses. Methods: Upper airway sounds were recorded in horses exercising on a high-speed treadmill at maximum heart rate (HR(MAX)) under 3 treatment conditions (ie, normal upper airway function [control condition], and after induction of left laryngeal hemiplegia or bilateral alar fold paralysis) in a randomized crossover design. Fundamental frequency, spectrograms using Gabor transform, and inte...
Patel JR, Földi J, Bateman H, Williams J, Didlick S, Stark R.The temperature sensitive and host range mutant clone 147 of equine herpesvirus 1 (EHV-1) was assessed for its ability to protect conventional, susceptible adult horses against respiratory infection by EHV-1 and equine herpesvirus 4 (EHV-4). Intranasal (IN) vaccination with 5.2 log(10) TCID(50) did not cause adverse clinical reactions although a limited virus shedding and viraemia (leukocytes) was observed in 11 of 15 and 10 of 15 vaccinated horses respectively. All 15 vaccinated horses showed a significant seroresponse to both EHV-1 and EHV-4 for virus neutralising (VN) antibody. None of 14 c...
Eenoo PV, Delbeke FT.Salbutamol is a beta-adrenergic agonist that is used in the treatment of asthma in humans and chronic obstructive pulmonary disease in horses. Because of its stimulating and growth promoting properties, it is prohibited by horse racing authorities. Recently a number of adapters (eg Equinehaler) have been designed, allowing the use of metered dose inhalers (MDI) approved for human use. However, information on detection times of salbutamol after administration of salbutamol in therapeutic doses by inhalation is lacking. In this study, 2 mg salbutamol (Ventolin) was administered to four standardb...
Vigre H, Chriél M, Hesselholt M, Falk-Rønne J, Kjaer Ersbøll A.A follow-up study focusing on health problems interfering with optimal training of Danish Standardbred trotters was conducted with the participation of seven professional trainers. Our aim was to estimate the incidence of health problems that cause interruptions of optimal training, and to identify associations between the hazard of lameness and selected risk factors. The study population was dynamic and contained data of 265 Standardbred trotters monitored during 5 months in 1997 and 1998. The horses were >or=2 years old. Optimal training was defined as when the horse followed scheduled tr...
Patel JR, Bateman H, Williams J, Didlick S.A German abortion isolate of EHV-1 (strain M8) was grown in equine dermal (ED) cells at a low multiplicity of infection in presence of 5-bromo-2-deoxy uridine. The resulting stock was dialysed, titrated and cloned by terminal dilution in ED cells grown in 96-well microtitration plates. Of 192 clones each originating from a single focus, clone 147 (C147) was found to be restricted for growth at and above temperatures of 38.5 degrees C. It was also restricted for growth at 37 degrees C in rabbit kidney (RK-13) cells which are widely used for the isolation and titration of EHV-1; hence clone 147 ...
Maleski K, Magdesian KG, LaFranco-Scheuch L, Pappagianis D, Carlson GP.A 13-day-old foal with profound tachypnoea and respiratory distress was examined. Thoracic radiographs revealed a severe, diffuse miliary pattern, and the foal was markedly hypoxaemic. It failed to improve with empirical treatment, and was euthanased. Lesions associated with Coccidioides immitis infection were identified at postmortem examination, and were limited to the lower respiratory tract.
Flaminio MJ, LaCombe V, Kohn CW, Antczak DF.A 12-year-old Quarter Horse mare that was nonresponsive to medical treatment was evaluated for chronic respiratory disease and hepatobiliary disease. Serum immunoglobulin concentrations were measured by use of radial immunodiffusion that revealed trace to nondetectable concentrations of IgG, IgG(T), IgM, and IgA. Use of serum protein electrophoresis confirmed agammaglobulinemia by the absence of the expected peak in the gamma region. In addition, vaccination with tetanus toxoid did not result in specific immunoglobulin production. Flow cytometric analysis of blood lymphocyte subpopulations rev...
Parente EJ, Martin BB, Tulleners EP, Ross MW.To evaluate the occurrence of dorsal displacement of the soft palate (DDSP) during high-speed treadmill (HSTM) exercise in racehorses, and determine treatment efficacy relative to the endoscopic findings observed during resting and HSTM endoscopic examination. Methods: Retrospective study. Animals-Ninety-two racehorses (74 Thoroughbreds, 18 Standardbreds). Methods: The signalment, history (clinical and race), treatments, and video recordings made during resting and HSTM endoscopy were reviewed in 92 racehorses that developed DDSP during HSTM exercise. Only horses that completed 3 starts before...
Couroucé-Malblanc A, Pronost S, Fortier G, Corde R, Rossignol F.There are a variety of reasons for poor performance in racehorses. Exercise intolerance has often been associated with subclinical respiratory abnormalities, and diagnostic aids are therefore used to enhance clinical detection. Physiological variables can also be measured in order to evaluate the metabolic reponse to exercise. This study evaluated the relationship between physiological measurements and upper airway videoendoscopy during a standardised treadmill exercise test and bronchoalveolar lavage (BAL) cytology in control horses (good racing performance, n = 14) and poor performers (n = 2...
Newton JR, Wood JL.In an epidemiological study of risk factors for exercise-induced pulmonary haemorrhage (EIPH) in young Thoroughbreds in the UK, in which 148 horses contributed 1614 horse-months of data, there were 64 (4%) episodes of endoscopically visible tracheal bleeding and 824 (51%) episodes of increased quantities of haemosiderophages in tracheal washes. There were increases in prevalence and risk of EIPH by both definitions with age from or = 4 years, season of sampling from winter (Nov-Jan) to autumn (Aug-Oct) and several different measures of airway inflammation, including tracheal mucus, neutrophil...
Marlin DJ, Schrotert RC, Cashman PM, Deaton CM, Poole DC, Kindig CA, McDonough P, Erickson HH.The present investigation utilised simultaneous measurements of chest (Ch) and abdominal (Ab) circumferences and respiratory airflow to test the hypothesis that Ch circumferential expansion contributes proportionally little to tidal volume in the running Thoroughbred. During exercise, there were only small changes in Ch and Ab circumference and no increase with increasing tidal volume. At rest, walk and trot, the flow, Ch and Ab signals were in phase. However, during canter and gallop, the Ch and Ab changes were 180 degrees out of phase with each other and both were out of phase with airflow. ...
Franklin SH, Naylor JR, Lane JG.Dorsal displacement of the soft palate (DDSP) is one of the most common obstructive conditions of the upper respiratory tract in the racehorse. The present study was conducted to determine the effects of intermittent dorsal displacement of the soft palate (DDSP) on ventilation and respiratory airflow during high intensity exercise. Videoendoscopic recordings were made of the nasopharynx and larynx simultaneously with measurements of airflow and respiratory gas exchange, during high-speed treadmill exercise in 9 horses with confirmed intermittent DDSP admitted for clinical investigation of poor...
Davis MS, Lockard AJ, Marlin DJ, Freed AN.In human subjects that exercise strenuously in cold weather, there is evidence that hyperventilation with cold air leads to peripheral airway cooling, desiccation and mucosal injury. Our hypothesis was that hyperventilation with cold air can result in penetration of unconditioned air (air that is not completely warmed and humidified) into the peripheral airways of exercising horses, resulting in peripheral airway mucosal injury. To test this hypothesis, a thermister-tipped catheter was inserted through the midcervical trachea and advanced into a sublobar bronchus in three horses that cantered ...
Funkquist P, Demmers S, Hedenstierna G, Jensen Waern M, Nyman G.It is not known if pulmonary function and gas exchange during exercise are altered after pyogranulomatous pneumonia caused by Rhodococcus equi infection in the foal. The aim was to evaluate whether pulmonary gas exchange during high intensity exercise was altered in mature Standardbreds with a history of R. equi pneumonia as foals. In 7 foals, R. equi pneumonia was confirmed and treated. At age 3 years, when these horses were subjected to professional training, an inclined treadmill exercise test including 4 speeds was performed. Samples were collected when a steady state in VO2 was obtained. ...
Escribano BM, Agüera EI, Vivo R, Santisteban R, Castejón FM, Rubio MD.The aim of this work was to assess whether progressive training caused an improvement in the nonspecific immune response of colts because several unusual infections are due to defects inherent in the neutrophilic function among which respiratory diseases are a major defect in the performance of athletes taking part in professional sports activities. A group of 7 Anglo-Arabian colts belonging to the Army was selected. These animals carry out training programmes for their participation in National Jumping Competitions. During a submaximal exercise test (heart rate 150 beats/min and lactate level...
Kingston JK, Bayly WM, Sides RH.Exercise-induced pulmonary haemorrhage has been associated with reduced performance in racing horses. However, it is unclear what volume of blood loss into the lungs impairs performance. The purpose of the present study was to determine the minimal volume of autologous Horses blood instilled into the airways that significantly affects performance and pulmonary function in exercising horses. Six Thoroughbred horses performed 2 exercise bouts on each of 4 treatment test days. Each exercise bout consisted of a 2 min warm-up at 4 m/s followed by running at a speed equivalent to 115% VO2max, until ...
Widdicombe JH, Pecson IS.Horses commonly suffer from respiratory diseases associated with excess secretions in the airway lumen, some of which are presumably derived from airway mucous glands. However, these structures have been little investigated in the horse. Accordingly, we describe here the number, distribution and size of equine tracheal mucous glands, and compare the data with similar information for other mammalian species. Two types of gland acini were present. In the thick connective tissue, up to 400 microm beneath the epithelium, gland acini were grouped in thin sheets that, in cross-section, averaged 20 m...
Abraham G, Brodde OE, Ungemach FR.In 12 healthy horses, the effects of the beta2-agonist clenbuterol and the glucocorticoid dexamethasone on the lymphocyte beta2-adrenoceptor density and affinity (determined by (-)-[125I]-iodocyanopindolol binding) as well as its responsiveness (assessed by lymphocyte cyclic AMP [cAMP] responses to 10 micromol/l (-)-isoprenaline) were studied. Clenbuterol treatment, 2 x 0.8 microg/kg/day i.v. for 12 days, decreased significantly ICYP binding sites by approximately 30-40%; concomitantly, lymphocyte cAMP response to (-)-isoprenaline was reduced. After withdrawal of clenbuterol, beta2-adrenocepto...
Nout YS, Hinchcliff KW, Samii VF, Kohn CW, Jose-Cunilleras E, Reed SM.Twelve foals, age 3-9 months, examined at The Ohio State University Veterinary Teaching Hospital between 1995 and 2000 were diagnosed with chronic pulmonary disease associated with marked interstitial opacity on radiographic examination. The most characteristic features were a history of respiratory disease of 1-3 months duration, marked clinical signs of respiratory disease, failure to yield a consistent pathogen from tracheobronchial aspirates and a predominantly interstitial pattern on thoracic radiographs. We attributed these signs to chronic interstitial pneumonia. Foals were treated with...
Stull CL, Rodiek AV.Transportation stress has been implicated as a predisposing factor to respiratory disease in horses. Cross-tying horses individually in stalls is common practice for transporting show and racehorses, but horses also travel in small groups or individually without being restricted by tying. The objective of this study was to compare physiological responses of horses travelling cross-tied or loose during 24 h of road transport. Ten horses were used in a cross-over design consisting of two 4 day trials. In the first trial, 6 horses were cross-tied, while 2 pairs of horses were loose in enclosed co...
Boguta L, Gradzki Z, Borges E, Maurin F, Kodjo A, Winiarczyk S.Bacteria isolated from nasal cavity of 80 foals with upper respiratory tract infection, as well as from 20 healthy foals, were examined. Within the group of sick animals, from 18 (22.5%) bacteria with recognized pathogenicity were isolated. Coagulase-negative staphylococci and Acinetobacter sp. were the dominant species identified (100 and 45%, respectively). No bacteria species with recognized pathogenicity were isolated from the group of healthy animals. Three cases of death within the group of sick foals were investigated. Rhodococcus equi in two cases and Klebsiella pneumoniae pneumoniae t...
Vengust M, Staempfli H, Prescott JF.A 10-year-old warmblood gelding was evaluated for intermittent pyrexia, dullness, weight loss, and progressive respiratory disease. Multifocal necrotic pneumonia and pleuritis due to Rhodococcus equi infection was diagnosed. Case management is discussed, as well as factors that may have led to this rare cause of pleuropneumonia in an adult horse.
Anzai T, Timoney JE, Kuwamoto Y, Wada R, Oikawa M, Higuchi T.To develop polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis for molecular typing of strains of Streptococcus zooepidemicus and to use the new typing method to analyze a collection of isolates from the respiratory tract of Thoroughbreds. Methods: 10 strains of S zooepidemicus, 65 isolates from the respiratory tract of 9 yearlings following long distance transportation, and 89 isolates from tracheal aspirates of 20 foals with pneumonia. Methods: Phenotypic variations in the SzP protein were detected by western immunoblot analysis. Using PCR-RFLP analysis, ge...
Guan F, Uboh CE, Soma LR, Luo Y, Li R, Birks EK, Teleis D, Rudy JA, Tsang DS.Clenbuterol (CBL) is a potent beta(2)-adrenoceptor agonist used for the management of respiratory disorders in the horse. The detection and quantification of CBL can pose a problem due to its potency, the relatively low dose administered to the horse, its slow clearance and low plasma concentrations. Thus, a sensitive method for the quantification and confirmation of CBL in racehorses is required to study its distribution and elimination. A sensitive and fast method was developed for quantification and confirmation of the presence of CBL in equine plasma, urine and tissue samples. The method i...
Hopster K, D￮ LR, Hopster-Iversen CCS, Driessen B.OBJECTIVE To evaluate efficacy of an alveolar recruitment maneuver (ARM) with positive end-expiratory pressures (PEEPs) in anesthetized horses ventilated with oxygen or heliox (70% helium and 30% oxygen). ANIMALS 6 healthy adult horses. PROCEDURES In a randomized crossover study, horses were anesthetized and positioned in dorsal recumbency. Volume-controlled ventilation was performed with heliox or oxygen (fraction of inspired oxygen [Fio] > 90%). Sixty minutes after mechanical ventilation commenced, an ARM with PEEP (0 to 30 cm HO in steps of 5 cm HO every 5 minutes, followed by incremental s...
Ainsworth DM, Reyner CL.To examine the effects of in vitro exposure to solutions of autologous horse blood (AHB) and autologous horse serum (AHS) on expressions of selected cytokine genes in equine primary bronchial epithelial cell (BEC) cultures and to contrast these responses to those induced in BEC cultures by endotoxin and hay dust. Methods: BEC cultures established from bronchi of 6 healthy horses. Methods: 5-day-old BEC cultures were treated with PBS solution, AHB (2 concentrations), AHS, hay dust solution, and lipopolysaccharide solution for 24 hours. Gene expressions of interleukin (IL)-8, IL-1β, chemokine (...
Scarratt WK, Crisman MV.Tumors of the equine respiratory tract occur infrequently. An accurate diagnosis of neoplasia of the respiratory tract is critical because the prognosis is usually grave. The clinical signs and diagnostic procedures are discussed for tumors of the nasal and paranasal sinuses, nasopharynx/larynx, guttural pouch and thorax including lung, pleura, and thymus.
Salinas C, Barriga K, Albornoz A, Alarcon P, Quiroga J, Uberti B, Sarmiento J, Henriquez C, Ehrenfeld P, Burgos RA, Moran G.Neutrophils display an array of biological functions including the formation of neutrophil extracellular traps (NETs), web-like structures specialized in trapping, neutralizing, killing and preventing microbial dissemination within the host. However, NETs contribute to a number of inflammatory pathologies, including severe equine asthma. Tamoxifen (TX) is a selective estrogen receptor modulator which belongs to the triphenylethyllenes group of molecules, and which is used as a treatment in all stages of estrogen-positive human breast cancer. Our previous results suggest that tamoxifen can modu...
Equine pulmonary aspergillosis is a rare deep mycosis often due to the hematogenous spread of hyphae after gastrointestinal tract disease. We describe herein the main clinic-pathological findings observed in a foal, which spontaneously died after showing diarrhea and respiratory distress. Necropsy and histopathological investigations allowed to diagnose pulmonary aspergillosis, which likely developed after necrotic typhlitis-colitis. Biomolecular studies identified section strain as the causative agent. Notably, severe oxalate nephrosis was concurrently observed. Occasionally, oxalate nephro...
Pozzoli C, Bertini S, Poli E, Placenza G, Menozzi A.β-adrenoceptor agonists are considered the most effective drugs to counteract bronchoconstriction in horses with asthma, but only clenbuterol is commonly employed in clinical practice. We evaluated the effects of different selective β agonists: clenbuterol, ritodrine, salbutamol, and fenoterol on the contractions of isolated bronchial muscle of horses induced by electrical field stimulation (EFS), carbachol, histamine, and KCl. All β agonists reduced the amplitude of contraction induced by the different stimuli but with variable efficacy and potency. Fenoterol and salbutamol were more effec...
Herholz C, Straub R, Busato A.Several indices of ventilatory heterogeneity can be identified from the volumetric capnogram and its graphic presentation, the single-breath diagram for CO2 (SBD-CO2). Physiologically based indices of pulmonary function (VTE, VCO2, FACO2, VDBohr% VDBohr%, VD/VTE, A1/A2) were calculated for healthy horses (group I, n = 5) and for horses with subclinical (group II, n = 7) or clinically manifest chronic obstructive pulmonary disease (COPD) (group III, n = 8) during tidal breathing and after medication with lobelin hydrochloride (Lobelin). We investigated the variability and repeatability of the l...
Swanson CR, Muir WW.The influence of positive end-expiratory pressure (PEEP) on the alveolar-arterial O2 tension difference [P(A-a)O2], physiologic right-to-left shunt fraction, physiologic dead space-to-tidal volume ratio, and hemodynamic variables was studied in halothane-anesthetized horses maintained in dorsal recumbency during controlled ventilation. Dobutamine was used to minimize the adverse cardiovascular consequences of PEEP. Six adult horses were anesthetized, using xylazine (2.2 mg/kg of body weight, IM), guaifenesin (50 mg/kg, IV), thiamylal Na (4.4 mg/kg, IV), and halothane (1.5 to 2% inspired) in 10...
Rees WA, Harkins JD, Lu M, Holland RE, Lehner AF, Tobin T, Chambers TM.To determine pharmacokinetics of single and multiple doses of rimantadine hydrochloride in horses and to evaluate prophylactic efficacy of rimantadine in influenza virus-infected horses. Methods: 5 clinically normal horses and 8 horses seronegative to influenza A. Methods: Horses were given rimantadine (7 mg/kg of body weight, i.v., once; 15 mg/kg, p.o., once; 30 mg/kg, p.o., once; and 30 mg/kg, p.o., q 12 h for 4 days) to determine disposition kinetics. Efficacy in induced infections was determined in horses seronegative to influenza virus A2. Rimantadine was administered (30 mg/kg, p.o., q 1...
Tomasic M, Mann LS, Soma LR.To determine the effects of endotracheal intubation on respiratory mechanics during xylazine sedation and xylazine-diazepam-ketamine anesthesia in adult horses. Methods: 5 healthy adult horses. Methods: Measurements were derived from recordings of respiratory gas flow, and transpulmonary and transtracheal pressures. Total pulmonary resistance (RT) was partitioned into upper airway resistance (extrathoracic portion of trachea, larynx, pharynx, nasal cavity, nares; RUA) and lower airway resistance (intrathoracic portion of trachea, bronchi, bronchioles). Baseline measurements were obtained in un...
Piccione G, Giudice E, Giannetto C, Mortola JP.Heart rate (FH) accelerates in inspiration and decelerates in expiration, a phenomenon known as Respiratory Sinus Arrhythmia (RSA). Although the presence of RSA has been documented in many species, how its magnitude compares among species is unknown. We asked whether the magnitude of RSA in a large mammal, the horse, differed from that of previously measured humans. From electrocardiogram and pneumography, the peaks and troughs of FH were identified breath-by-breath in four horses (Italian Saddlebred geldings) during resting wakefulness. RSA was computed as the peak-trough FH difference, in pe...
Kendall A, Mosley C, Bröjer J.Signs of tachypnea after sedation of febrile horses with alpha2-agonists have been noted previously but have not been further investigated. Objective: To examine the effects of xylazine and detomidine on respiratory rate and rectal temperature in febrile horses and to investigate if either drug would be less likely than the other to cause changes in these variables. Methods: Nine febrile horses and 9 healthy horses were included in the study. Methods: Horses were randomly assigned to sedation with xylazine 0.5 mg/kg or detomidine 0.01 mg/kg. Heart rate and respiratory rate were recorded before...
Tucker ML, Sumner D, Reinink SK, Wilson DG, Carmalt JL.To compare laryngeal impedance, in terms of air flow and pressure, following arytenoid corniculectomy (COR) versus 3 other airway interventions (left-sided laryngoplasty with ipsilateral ventriculocordectomy [LLP], LLP combined with COR [LLPCOR], and partial arytenoidectomy [PA]) performed on cadaveric equine larynges with simulated left recurrent laryngeal neuropathy (RLN) and to determine whether relative laryngeal collapse correlated with the interventions performed. Methods: 28 cadaveric equine larynges. Methods: Each larynx in states of simulated left RLN alone and with airway interventio...
Eenoo PV, Delbeke FT.Salbutamol is a beta-adrenergic agonist that is used in the treatment of asthma in humans and chronic obstructive pulmonary disease in horses. Because of its stimulating and growth promoting properties, it is prohibited by horse racing authorities. Recently a number of adapters (eg Equinehaler) have been designed, allowing the use of metered dose inhalers (MDI) approved for human use. However, information on detection times of salbutamol after administration of salbutamol in therapeutic doses by inhalation is lacking. In this study, 2 mg salbutamol (Ventolin) was administered to four standardb...
Vrins A, Doucet M, Nunez-Ochoa L.A retrospective of 69 bronchoalveolar lavages (BAL) on horses was done to investigate the relationship between bronchoalveolar cell types and clinical signs in horses with small airway disease. Horses were grouped according to clinical findings. The groups were as follows: I. cough only (n = 14), II. cough with mucopurulent secretions in the trachea (n = 14), III. cough, mucopurulent secretions in the trachea and abnormal lung sounds (n = 24) and IV., all of the above plus dyspnea at rest (n = 17). An asymptomatic group was formed from horses in the same population to serve as control (n = 8)....
McKenzie EC, Mills JN, Bolton JR.Gastric squamous cell carcinoma was diagnosed in three horses. Clinical signs observed in all cases were weight loss, anorexia and lethargy. Respiratory signs were prominent in one case. All three horses had depressed albumin and elevated globulin and fibrinogen concentrations. Two horses were mildly anaemic. Inflammatory exudates were present in peritoneal cavities in all cases, and cytological evaluation provided a positive diagnosis of squamous cell carcinoma in two cases. Pleural fluid samples taken from two cases were also classified as inflammatory exudates, but no neoplastic cells were ...
Ainsworth DM, Appleton JA, Antczak DF, Santiago MA, Aviza G.A controlled experimental system for the evaluation of pulmonary immune responses in horses with "heaves" (recurrent airway obstruction) has been developed. We hypothesized that the humoral immune response to an inhaled antigen in diseased horses would be different from that of healthy horses and that chronic pulmonary inflammation would bias the production of IgG isotypes in diseased horses as compared to healthy horses. Healthy and affected horses were housed in a natural challenge environment (stabled, fed dusty hay) and exposed by inhalation, to a nebulized solution of keyhole limpet hemoc...
Robinson NE, Derksen FJ, Olszewski M, Berney C, Boehler D, Matson C, Hakala J.In six COPD-affected horses, we analysed the factors responsible for the changes in pleural pressure (delta Pplmax) that occur during tidal breathing. Four-hundred-and-sixty-eight measurements of each parameter: pulmonary resistance (RL), dynamic elastance (Edyn), air flow rates, and the timing of breathing, were gathered during a trial of the bronchodilator pirbuterol. Data were placed into seven ranks, based on the magnitude of delta Pplmax; rank 1: 5-15; rank 2: 15-25; rank 3: 25-35; rank 4: 35-45; rank 5: 45-55; rank 6: 55-65; and rank 7 > 65 cm H2O. Up to rank 4 (45 cm H2O), the increa...
Schwarz B, Klang A, Bezdekova B, Sárdi S, Kutasi O, Hoven R.Equine multinodular pulmonary fibrosis (EMPF), a progressive fibrosing interstitial lung disease has been associated with gammaherpesviruses. This case series describes five horses with EMPF. Three of the horses (two in Hungary, one in the Czech Republic) were diagnosed with EMPF ante mortem. They presented with typical clinical signs of EMPF including dyspnoea and weight loss. Arterial blood gas analysis revealed hypoxaemia. Blood work showed signs of inflammation like neutrophilia and hyperfibrinogenaemia. An endoscopic examination of the respiratory tract including cytology and culture of t...
Art T, Duvivier DH, Votion D, Anciaux N, Vandenput S, Bayly WM, Lekeux P.The present study was conducted to understand better the mechanisms leading to the decrease in exercise capacity observed in horses suffering from chronic obstructive pulmonary disease (COPD). Five COPD horses were submitted to a standardized submaximal treadmill exercise test while they were in clinical remission or in acute crisis. Respiratory airflow, O2 and CO2 fractions in the respired gas, pleural pressure changes and heart rate were recorded, and arterial and mixed venous blood were analyzed for gas tensions, hemoglobin, and plasma lactate concentrations. O2 consumption, CO2 production,...
Nout YS, Hinchcliff KW, Samii VF, Kohn CW, Jose-Cunilleras E, Reed SM.Twelve foals, age 3-9 months, examined at The Ohio State University Veterinary Teaching Hospital between 1995 and 2000 were diagnosed with chronic pulmonary disease associated with marked interstitial opacity on radiographic examination. The most characteristic features were a history of respiratory disease of 1-3 months duration, marked clinical signs of respiratory disease, failure to yield a consistent pathogen from tracheobronchial aspirates and a predominantly interstitial pattern on thoracic radiographs. We attributed these signs to chronic interstitial pneumonia. Foals were treated with...
Hay WP, Tulleners E.Granulation tissue masses arising from the axial surface of the arytenoid cartilage in 25 horses were excised using a contact neodymium:yttrium aluminum garnet laser. A technique that eliminated the need for general anesthesia or laryngotomy was developed for transen-doscopic removal of the masses in standing horses. Nineteen racehorses made abnormal upper respiratory tract noises or their performance was decreased, whereas six horses not used for racing had a history of stertor (five horses) or epistaxis after nasogastric intubation (one horse). Thoroughbreds were significantly (p = .0126) ov...
Ohta M, Kambayashi Y, Mita H, Kuroda T, Bannai H, Tsujimura K, Yamanaka T, Garvey M, Cullinane A, Yamayoshi S, Kawaoka Y, Nemoto M.Updating vaccine strains is essential to control equine influenza. We evaluated the protective efficacy of an inactivated equine influenza vaccine derived from viruses generated by reverse genetics (RG) in horses in an experimental viral challenge study. Wild-type (WT) virus (A/equine/Tipperary/1/2019) and virus generated by RG (consisting of hemagglutinin and neuraminidase genes from A/equine/Tipperary/1/2019 and six other genes from high-growth A/Puerto Rico/8/34) were inactivated by formalin for vaccine use. Twelve 1-year-old naïve horses with no antibodies against equine influenza virus w...
Alnaeem A, Shawaf T, Ali AM, Hemida MG.In the current study, we are investigating the viral causes of some respiratory clinical signs in some animals belongs to the family Equidae in eastern Saudi Arabia (ESA) during winter- 2019. We observed the progression of severe respiratory clinical signs among some horses, donkeys, and ponies in the ESA. Animals showed rapid respiration, fever, nasal discharges (started as serous then changed into mucopurulent with the progression of the infection per some animals). We conducted a longitudinal study to monitor the progression of this outbreak. We conducted molecular surveillance for the infl...
Zarski LM, High EA, Nelli RK, Bolin SR, Williams KJ, Hussey G.Equine herpesvirus 5 (EHV-5) infection is associated with pulmonary fibrosis in horses, but further studies on EHV-5 persistence in equine cells are needed to fully understand viral and host contributions to disease pathogenesis. Our aim was to develop a quantitative PCR (qPCR) assay to measure EHV-5 viral copy number in equine cell cultures, blood lymphocytes, and nasal swabs of horses. Furthermore, we used a recently developed equine primary respiratory cell culture system to study EHV-5 pathogenesis at the respiratory tract. PCR primers and a probe were designed to target gene E11 of the EH...
Higuchi T, Hashikura S, Hagiwara S, Gojo C, Inui T, Satoh S, Yoshida M, Fujii M, Hidaka D, Tsubaki S, Takai S.Although isolation of Rhodococcus equi from tracheobronchial aspirates is thought to be a definitive diagnosis of R. equi pneumonia in foals, virulence of isolates from the aspirates of infected foals remains obscure. In the present study, transtracheal aspirates were collected from thirty-one 1- to 6-month-old foals, which showed clinical signs of respiratory tract infection, and R. equi isolates were analyzed for the presence of virulence plasmids and virulence-associated antigens. Moreover, this method was compared with a serodiagnosis by an enzyme-linked immunosorbent assay (ELISA) to eval...
Winther L, Baptiste KE, Friis C.Ampicillin concentrations in pulmonary epithelial lining fluid (PELF) and plasma was studied after single intravenous ampicillin administration (15mg/kg) or single intragastric administration of its prodrug, pivampicillin (19.9mg/kg) to horses and discussed in relation to minimum inhibitory concentrations (MIC) of common equine respiratory pathogens. After intravenous administration, elimination of ampicillin was fast and not detectable in plasma after 12h in three out of six horses. Pivampicillin was absorbed well in non-fasted horses with an oral bioavailability of 36%. The degree of penetra...
Dean PW.Abnormalities of the nasal cavity, pharynx, larynx, and trachea result in respiratory noise and exercise intolerance. Clinical features of common upper respiratory conditions of performance horses are reviewed with emphasis on diagnosis, treatment, and risk factors that affect the outcome of surgical treatment.
Franklin SH, Usmar SG, Lane JG, Shuttleworth J, Burn JF.It has long been recognised that the production of abnormal respiratory sounds by horses during exercise is frequently associated with upper airway obstructions. Respiratory acoustic measurements have shown promise in investigation of upper airway disorders in man and, more recently, in horses with experimentally-induced obstructions. Objective: To evaluate sounds from exercising horses with naturally occurring dynamic obstructions of the upper respiratory tract and to compare these with those from normal horses in order to determine whether different obstructions produce characteristic spectr...
Koterba AM, Wozniak JA, Kosch PC.Changes in pattern of airflow, sequence of respiratory muscle activation and generated pressures were measured serially in a group of foals during the first year post partum, in order to describe the maturation of the equine breathing pattern. In neonatal foals, inspiration and expiration were both primarily active and airflow pattern was essentially monophasic. By age 1 year, foals displayed essentially the same breathing pattern previously described in adult horses, utilising a combination of active and passive inspiration and expiration to breathe around, rather than from, the relaxation vo...
