The trachea, commonly referred to as the windpipe, is a vital component of the equine respiratory system. It functions as a conduit for air passage between the larynx and the bronchi, facilitating respiration in horses. Structurally, the equine trachea is composed of a series of cartilaginous rings that maintain its shape and provide necessary support, preventing collapse during inhalation and exhalation. The inner lining of the trachea is lined with ciliated epithelium and mucus-producing cells, which help trap and expel particulates and pathogens, contributing to respiratory health. This page gathers peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, and clinical implications of tracheal health and diseases in horses.
Wilkie BN.Effective resistance to respiratory tract infection depends principally on specific immunity on mucosal surfaces of the upper or lower respiratory tract. Respiratory tract immune response comprises antibody and cell-mediated systems and may be induced most readily by surface presentation of replicating agents but can result from parenteral or local presentation of highly immunogenic antigens. Upper and lower respiratory tract systems differ in immunologic competence, with the lungs having a greater inventory of protective mechanisms than the trachea or nose. Several effective vaccines have bee...
O'Callaghan MW, Sanderson GN.A method for performing bronchography in standing nonanaesthetized horses was developed. Bronchography was performed by insufflating the previously intubated trachea with a mixture of 120 to 200 g of finely powdered barium sulphate mixed with 3 to 7 g of powdered methyl cellulose. The mixture was delivered from an ether vaporiser into which compressed air was blown. Premedication with atropine sulphate immediately before insufflation minimised bronchoconstriction. Satisfactory bronchograms with contrast visible down to the seventh and eighth bronchial divisions were obtained in 80 per cent of ...
Speirs VC, van Veenendaal JC, Harrison IW, Smyth GB, Anderson GA, Wilson DV, Gilbo B.Endoscopic examinations of the upper respiratory tract were done on 92 of 314 Standardbred horses that raced one or more times at 4 consecutive, weekly race meetings. Although participation was voluntary, the characteristics of the population of horses examined were not statistically different from those of all horses that raced. No horse showed epistaxis, but 34 (32.4%) examinations of the trachea revealed blood that ranged from a trace in the tracheal mucus to large amounts scattered over the tracheal walls. Forty-four horses exhibited minor degrees of pharyngeal lymphoid hyperplasia, 2 had ...
Eyre P, Gaviller P, Thorsen J.Groups of guinea-pigs were vaccinated with equine influenza A-1 virus and helically-cut tracheal strips were subsequently contracted to carbachol (EC50) and relaxed to isoprenaline at 3, 5 and 10 days post-vaccination. Tracheas from another group were contracted to phenylephrine in the presence of propranolol. Compared to controls, responses to isoprenaline in virus-infected tracheas were significantly potentiated at days 3 and 10. Virus infection significantly inhibited tracheal responsiveness to phenylephrine. It appears that enhancement of isoprenaline may be caused by diminished reactivity...
Barber SM.A three year old Thoroughbred filly was examined because of bilateral nasal discharge and external swelling of the left laryngeal area. Endoscopy revealed an enlarged left arytenoid cartilage, left laryngeal hemiplegia and drainage of purulent material into the lumen of the larynx. Radiographs showed a large fluid and gas filled cavity overlying the caudal larynx and cranial trachea. Surgical drainage and debridement of the abscess led to complete healing by secondary intention. Laryngeal ventriculectomy was performed as a treatment for left laryngeal hemiplegia, but a grave prognosis for resp...
George LW, Tanner ML, Roberson EL, Burke TM.A 6-year-old Thoroughbred gelding was examined because of respiratory disease that developed after it was placed on pasture occupied by a donkey. Clinical signs in the gelding included a harsh, dry paroxysmal cough and increased expiratory effort. Eosinophils were seen in smears of mucus aspirated from the trachea and the bronchi. Immature, 5th-stage Dictyocaulus arnfieldi was identified in the tracheal mucus. The cough and other clinical signs were not diminished by corticosteroid therapy or by the administration of bronchodilators. Treatment with 10-fold therapeutic dosages of thiabendazole ...
Rose RJ, Hartley WJ, Baker W.Bilateral laryngeal paralysis is described in 5 Arabian and part-Arabian foals aged between 23 and 35 days. Tracheotomies resulted in complete relief of dyspnoea. Two cases showed recovery of abductor function of the right arytenoid cartilage after 3 weeks and one of these cases later recovered left abductor function. Four of the foals were autopsied at various times from one week to 6 months after the onset of respiratory obstruction. Histology of the recurrent laryngeal nerves showed active Wallerian degeneration and loss of nerve fibres in many fascicles in cases affected for one to 2 weeks...
Pascoe JR, Ferraro GL, Cannon JH, Arthur RM, Wheat JD.Of 235 Thoroughbred racehorses examined with a flexible fiberoptic endoscope within 2 hours of racing to determine the frequency of exercise-induced pulmonary hemorrhage (EIPH), 103 (43.8%) had various degrees of hemorrhage in the tracheal lumen. Two of these horses (0.8%) subsequently had blood flow from the nostrils. Blood seemed to originate from the lung. Statistical analysis of frequency data for 191 horses which finished in 1st, 2nd, and 3rd places did not show any relationship between EIPH and horse's age, sex, or finishing position. However, a trend toward an increased frequency of EIP...
Tate LP, Koch DB, Sembrat RF, Boles CL.A surgical technique for resection of a portion of the trachea followed by end-to-end anastomosis was developed on 4 clinically normal horses. The trachea healed without complications in 3 of the horses in which 3 tracheal cartilages were removed. Five tracheal cartilages were removed from the 4th horse. It had to be euthanatized because of excessive suture line tension and wound disruption, which occurred during recovery from anesthesia. Suture line tension was measured on 3 other clinically normal horses positioned in dorsal recumbency immediately after euthanasia after 3 and 5 tracheal cart...
Hanna CJ, Eyre P.Trimetaquinol [TMQ: 1-(3’,4‘,5’-trimethoxybenzyl)6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline hydrochloride] a potential p-sympathomimetic bronchodilator (Iwasawa & Kiyomoto 1967), has been shown to be an effective tracheal smooth muscle relaxant in guineapigs (Iwasawa & Kiyomoto 1967; Brittain 1972; Brittain et a1 1970, 1976) and an inhibitor of experimental bronchospasm in guinea-pigs and cats (Brittain et a1 1970; Brittain 1972). In addition, clinical studies with TMQ indicated that the drug was an effective bronchodilator in mild to moderate asthma (Yamamura & Kishimoto 1968). It may...
MacKay RJ, Urquhart KA.Eight mature horses which had been affected with a moist cough for six weeks were found to have large numbers of eosinophils in tracheal mucus samples taken by transtracheal washing. These horses were kept on irrigated pasture and fed a hay-free diet. A companion yearling donkey was found to be passing Dictyocaulus arnfieldi larvae in its faeces. Two oral treatments with a dose of thiabendazole (440 mg/kg) resulted in the resolution of the clinical signs and the disappearance of eosinophils from transtracheal washings. The eosinophilic bronchitis seen in these horses was presumed to be a manif...
Chand N, Eyre P.Histamine, 2-methylhistamine (a specific H1-agonist), 5-HT, PGF2alpha, SRS-A, bradykinin (BK) and carbachol contract bronchial and tracheal smooth muscles of the horse. Isoprenaline, PGE1, E2, dimaprit and 4-methylhistamine (last two = specific H2-agonists) relaxed airways which were partially contracted to carbachol. Mepyramine (a specific H1-antagonist) selectively antagonized contractions to histamine. In the presence of mepyramine, histamine caused relaxation of airways partially contracted to carbachol. Metiamide and burimamide (specific H2-antagonists) specifically antagonized or reverse...
Robinson NE, Sorenson PR.Obstruction of the upper and lower airways is common in horses. In the upper airway, paresis of abductor muscles of the nares and larynx allows inspiratory collapse of soft tissues, which is accentuated by factors increasing upper airway resistance and by high inspiratory flow rates. Intrapulmonary airway obstruction occurs due to accumulation of secretions, release of chemical mediators in response to a variety of stimuli, and parasympathetic stimulation of airways. Obstruction of large airways increases the work of breathing, whereas obstruction of small airways may cause no measurable incre...
Moorthy AR, Spradbrow PB.Mycoplasmas were isolated from two of 43 nasal swabs taken from live horses, and from one of 28 tracheal swabs taken from slaughtered horses. The slaughtered horse that yielded mycoplasmas had no gross pathological changes in the respiratory tract, but the nasal isolations were made from horses with rhinitis. The three mycoplasmas could be distinguished by cultural characteristics, and probably they represent three different species.
Pavelka M, Ronge HR, Stockinger G.Tracheal epithelia of ten different mammals were investigated with the light and the electron microscope. Characteristic differences were found concerning the thickness of the epithelia, the length of the cilia, the density of the cells in the epithelia, the numerical distribution of the different cells and their ultrastructure. Special attention was paid to the morphology of the kinetosomes. Brush cells and chromaffin cells, which are sparsely distributed in the different tracheal epithelia, were discussed.
Scott EA.A weanling Quarter Horse filly developed ventral swelling of the lower cervical area after difficult passage of a stomach tube for deworming. Intermittent bilateral nasal discharge developed. Radiography revealed fluid and gas density dorsal to the trachea and esophagus. Surgical incision with drainage and debridement of the abscess and fistulous tract, facilitated by use of drains, led to complete recovery. Contrast medium injected after surgery demonstrated a communication between the abscess and the pharyngeal region.
Mair TS, Stokes CR, Bourne FJ.Lavage techniques were used to obtain secretions from the nasal cavity, trachea and bronchi of conscious horses. The techniques, which utilised fibreoptic endoscopy for recovery of tracheal and bronchial secretions, were well tolerated by the horses. The recovery rates of the lavaged fluids were acceptable, but were lowest for bronchial secretions, and there was minimal contamination by blood. The fluids were analysed for IgG and IgM by single radial immunodiffusion, and for IgA and albumin by rocket immunoelectrophoresis. Relative to albumin there was significantly more IgA and IgM, and signi...
Maisi P, Paananen M, Koivunen AL.Seventeen trotters, eight healthy and nine with a mild respiratory disease, underwent a submaximal treadmill exercise. Heart rate, breathing frequency, intrapleural pressure difference (IP difference) as well as haematocrit and concentration of lactic acid in blood were monitored before exercise, during exercise and during recovery. The activities of beta-glucuronidase and plasmin, total proteolytic activity and trypsin inhibitory capacity were measured from the tracheal fluid before and after exercise. IP difference significantly increased during exercise and returned to normal values within ...
Roethlisberger-Holm K, Roepstorff L, Obel N.After giving an account of the principles of pressure measurement in flowing air and a review of the literature on tracheal catheters, the authors describe the construction, the introduction and the function of their own transtracheal catheter. This is a teflon catheter with several side-ports which is introduced into the cervical trachea by a guide technique. After introduction, the catheter is stiffened by the insertion of 2 steel wires. The catheter was studied in model experiments concerning: a) the ability to measure the static pressure in flowing air, and b) the dynamic accuracy of a rec...
Breuer D.In spite of regular vaccinations against equine influenza we are still observing a high rate of patients with respiratory problems in the equine practice. In our practice in Munich Riem, into which a horse clinic has been integrated, 4000 horses have been treated in 1985 alone. 874 of these showed some form of respiratory disease (= 22%). All of the 4000 horses have only been treated curatively, i.e. preventive forms of treatment such as vaccinations, deworming and examinations for insurance companies and prior to selling have not been taken into account. From 1983 until today in our clinic 25...
Kirker-Head CA, Jakob TP.An Arabian mare was referred with traumatically induced complete transection of the trachea. A temporary airway was established through the open wound at the site of the rupture. Resection of devitalized tissue including 3 tracheal ring segments, and anastomosis of the tracheal ends was subsequently performed under general anesthesia. Wound healing was complicated by a peritracheal abscess, which responded successfully to drainage and antibiotic administration.
Gregson R, Clutton RE.A 7-year-old gelded Irish sports horse weighing 650 kg was anesthetized on 2 consecutive days for lavage of a septic right radio-carpal joint. On both occasions the endotracheal tube connector, which had been bound in medical tape to produce an airtight seal, functioned as a unidirectional valve during mechanical ventilation, retarding expiration, imposing positive end expiratory pressure (PEEP), and probably continuous positive airway pressure (CPAP). The equipment dysfunction was not identified on either occasion despite close inspection prompted by progressive increases in airway pressure a...
Dixon PM, Railton DI, McGorum BC.The majority of 270 adult horses with chronic pulmonary diseases had excessive volumes of respiratory secretions (RS) present in their trachea, elevated tracheal RS neutrophil ratios and lowered arterial oxygen partial pressures. Some control horses, had inexplicably elevated trachael RS neutrophil ratios. Only the chronic obstructive pulmonary disease (COPD) affected group had significantly elevated bronchoalveolar lavage fluid (BALF) neutrophil ratios. Maximal intrapleural pressure changes (max dPpl) were raised in 48% of COPD cases and rarely with other pulmonary disorders. Arterial pH or c...
Powell RJ, du Toit N, Burden FA, Dixon PM.There is limited information on the gross tracheal morphology of donkeys with or without tracheal abnormalities. Objective: To: 1) examine the morphology of tracheas of donkeys with and without clinical and/or post mortem evidence of tracheal obstruction; 2) record the cross-sectional dimensions and shapes of tracheal rings at fixed sites; and 3) document prevalence, sites and characteristics of detected tracheal abnormalities. Methods: The tracheas of 75, predominantly aged (median age 30 years, range 7-48 years) donkeys that died or were subjected to euthanasia on humane grounds were examine...
Anderson GF, Landsheft B.Performance horses should be thoroughly examined before sale to detect any defects that could render them unsuitable for the purchaser's intended use. With the horse in its stall, the eyes, nasolacrimal puncta, external ear canals and mouth are examined, the rectal temperature measured and the heart, lungs, trachea and sinuses auscultated. Moving the horse out of the stall, the head, parotid glands, mandibular lymph nodes, larynx, neck muscles, jugular veins and cervical vertebrae are inspected. The scapula, point of the shoulder, withers, tuber sacrale and point of the hip are palpated, after...
Art T, Tack S, Kirschvinck N, Busoni V, Votion D, Freeman K, Lekeux P.This study aimed at measuring the functional consequences and the pulmonary cytology changes following a simulation of pulmonary haemorrhage. Pulmonary function tests including lobeline-induced hyperventilation, cytology of tracheo-bronchial wash (TBW) and thoracic radiographs were performed before, as well as 1, 7, 14 and 28 days after, the instillation of 300 ml of blood into the lungs of 4 horses deemed free of exercise-induced pulmonary haemorrhage (Group 1). Control data (Group 2) were obtained by instilling the same volume of saline into the lungs of the same horses in a crossover design...
Haynes PF.The intent and extent of the respiratory tract examination relevant to purchase are dictated by numerous factors, including historical information, signs suggestive of respiratory tract abnormalities, intended use of the horse, and economic considerations. Following a thorough and systematic examination of the horse at rest, evaluation during and following exercise may be warranted. The physical examination should include evaluation of regional symmetry of the head, neck, and thorax; evaluation of nasal airflow and patency; palpation of the nasal septum, larynx, and trachea; examination for su...
Viscardi V, Jorge ML, Silva KM, Sad EP, Fonseca AB, Alencar NX, Lessa DA.Collection of fluid from the lower respiratory tract (LRT) plays an important role in both the pathophysiological investigation and diagnosis of respiratory tract disease. Enzymes such as ALP are, among others, indicators of cell damage or death, type II pneumocyte proliferation, and neutrophil invasion, and have been useful as biomarkers of respiratory disease in other species. Objective: The purpose of this study was to determine and compare tracheal wash (TW) ALP activity in healthy horses and horses with LRT inflammation (LRTI) determined by TW cytology profile. Methods: Tracheal washes we...
Sellon DC, Besser TE, Vivrette SL, McConnico RS.Recently, a technique was described for amplification of Rhodococcus equi-specific chromosomal and vapA DNA from blood and tracheal wash fluids. It was hypothesized that this technique would be more sensitive than standard culture techniques or serology for diagnosis of R. equi pneumonia in foals. Tracheal wash fluid, nasal swabs, whole blood samples, and serum samples from 56 foals with pneumonia were analyzed. Final clinical diagnosis was determined by the attending clinician on the basis of final interpretation of all available information about each foal, including clinical presentation, d...
Orr JA, Fraser DB, Shirer HW, Wagerle LC, DeSoignie RC.Carbon dioxide concentrations were increased during expiration in the upper one-half of the trachea, pharynx, and nasal sinuses to determine if elevation of upper airway CO2 would alter breathing or arterial blood gases in the awake pony. Carbon dioxide (100%) was injected into the midcervical trachea via a chronically implanted transcutaneous cannula during the first part of the animal's expiration. This maneuver elevated upper airway expiratory CO2 concentrations but prevented any exogenous CO2 from entering the lung and being absorbed into the arterial blood. Twelve experiments were perform...
Zhang XY, Zhu FX, Robinson NE.To investigate the effects of changes in intracellular cAMP on alpha 2-adrenoceptor (AR)-induced inhibition of airway acetylcholine (ACh) release, we examined the effects of the alpha 2-AR agonist clonidine on electrical field stimulation-evoked ACh release from equine tracheal parasympathetic nerves before and after treatment with 8-bromo-cAMP or forskolin. We also tested whether charybdotoxin (ChTX)- or iberiotoxin (IBTX)-sensitive Ca(2+)-activated K+ channels mediate alpha 2-AR-induced inhibition by examining the effect of clonidine in the absence and presence of ChTX or IBTX on ACh release...
Gordon D, Clark-Price S, Keating S, Schaeffer DJ, Lascola KM.This study evaluated the effects of various flow rates and fractions of oxygen on arterial blood gas parameters and on the fraction of inspired oxygen (FO) delivered to the distal trachea. Oxygen was administered to 6 healthy, conscious, standing, adult horses via single nasal cannula positioned within the nasopharynx. Three flow rates (5, 15, 30 L/min) and fractions of oxygen (21, 50, 100%) were delivered for 15 minutes, each in a randomized order. FO was measured at the level of the nares and distal trachea. Adverse reactions were not observed with any flow rate. FO (nares and trachea) and P...
Léguillette R, Steinmann M, Bond SL, Stanton B.Poor performance is often suspected to be associated with EIPH in barrel racing horses; however, there are no published reports of EIPH for this discipline. The prevalence of EIPH in barrel racing horses is also unknown. Objective: This study was performed to determine the prevalence of EIPH and signs of airway inflammation in barrel racing horses under normal racing conditions in Alberta. Methods: About 170 barrel racing horses. Methods: Observational cross-sectional study. Tracheobronchoscopic examinations were performed at least 30 minutes postrace. Video recordings were scored off-site ind...
Floriano D, Watkins AR, Hopster K.To evaluate the efficacy of 2 different oxygen delivery strategies-intranasal and tracheal insufflation-on the inspired fraction of oxygen (FIO2) in standing horses and to determine the time needed for arterial oxygen partial pressure (PaO2) equilibration. Methods: 6 healthy adult horses. Methods: In this blinded, randomized crossover design study, horses were randomly assigned to receive oxygen via nasal cannula (group N) or transcutaneous tracheal catheter (group T). After placement of venous and arterial catheters, FIO2 was measured through a catheter placed into the distal portion of the t...
Sonea IM, Bowker RM, Broadstone RV, Robinson NE.The tone of respiratory smooth muscle is largely determined by the input from autonomic nerves. The distribution of adrenergic and selected nonadrenergic, non-cholinergic (NANC) nerves in the normal equine trachealis muscle was investigated using immunohistochemistry. The smooth muscle of the trachealis was found to contain numerous nerves immunoreactive for an enzymatic marker of adrenergic nerves, as well as many nerves immunoreactive for a putative NANC neurotransmitter, peptide histidine isoleucine, a potent bronchodilator. The tissue surrounding the respiratory smooth muscle contained num...
Vinardell T, David F, Galezowski AM, Ali M, Qasim M, Massie SL, McCrae P, Filho S, Leguillette R.Swimming is used for rehabilitation of musculoskeletal injuries and for conditioning to improve equine fitness. However, there are anecdotal reports that suggest that tethered swimming can induce epistaxis, likely secondary to exercise-induced pulmonary hemorrhage (EIPH). The objective of this observational, prospective study was to investigate if EIPH occurs during intensive free-swimming training sessions (5 × 70m) using 15 endurance horses. On tracheo-bronchoscopic evaluations following swimming, low grade mucus scores were observed, but no tracheal blood was observed. Bronchoalveolar la...
Rakesh V, Rakesh NG, Datta AK, Cheetham J, Pease AP.Computational fluid dynamics (CFD) models provide the means to evaluate airflow in the upper airways without requiring in vivo experiments. Objective: The physiological conditions of a Thoroughbred racehorse's upper airway during exercise could be simulated. Methods: Computed tomography scanned images of a 3-year-old intact male Thoroughbred racehorse cadaver were used to simulate in vivo geometry. Airway pressure traces from a live Thoroughbred horse, during exercise was used to set the boundary condition. Fluid-flow equations were solved for turbulent flow in the airway during inspiratory an...
Fenger CK, Kohn CW.A 20-month-old Quarter Horse stallion was admitted for evaluation of labored breathing, honking cough, and bilateral epistaxis that were caused by pneumonia and collapsed trachea. A transtracheal aspiration revealed highly cellular, serosanguineous fluid. Radiography revealed a patchy alveolar pattern and a narrowed tracheal lumen. Endoscopy confirmed narrowing of the tracheal lumen. Streptococcus zooepidemicus was isolated on culture of the transtracheal aspirate. The horse responded to penicillin treatment, and the tracheal collapse improved endoscopically after 4 days, with complete recover...
Wang ZW, Yu MF, Robinson NE, Derksen FJ.The present study was conducted to determine if acetylcholine (ACh) release from airway cholinergic nerves is increased and if modulation of ACh release by prejunctional receptors is altered in horses with heaves, an obstructive airway disease characterized by airway inflammation and bronchospasm. Trachealis strips and bronchial segments of normal horses and horses affected with heaves were suspended in 2-ml tissue baths. ACh release was induced by electrical field stimulation and the bath ACh content was measured by high performance liquid chromatography (HPLC) with electrochemical detection....
Hashikura S, Higuchi T, Taharaguchi S, Orita Y, Nanao Y, Takai S.The reliability of preparing bacteriological cultures from nasotracheal aspirates of foals routinely in order to diagnose R. equi pneumonia in foals was studied by isolating Rhodococcus equi from specimens obtained from 96 foals by nasotracheal aspiration with a silicon catheter. Results were compared with specimens obtained from 21 foals by transtracheal aspiration (percutaneous tracheal puncture). These 117 foals showed clinical signs of respiratory tract infection at sampling. R. equi was isolated from 14 of 21 (66.7%) specimens by transtracheal aspiration and from 59 of 96 (61.4%) specimen...
MacNeill AL, Alleman AR, Franklin RP, Long M, Giguère S, Uhl E, López-Martinez A, Wilkerson M.A 5-year-old Paso-Fino mare was presented for severe respiratory distress. The mare had foaled 2 months prior to presentation. The horse was in poor body condition with a dull hair coat. A mild fever was noted during physical examination and increased bronchovesicular sounds were auscultated. Thoracic radiographs showed an interstitial pattern and an alveolar infiltrate with distinct air bronchograms. Moderate purulent inflammation with increased mucus was observed in tracheal wash fluid, but no infectious agents were identified. A bronchoalveolar lavage (BAL) contained a large amount of mucus...
McClure SR, Taylor TS, Honnas CM, Schumacher J, Chaffin MK, Hoffman AG.Permanent tracheal stomas were created in seven sedated, standing horses with severe upper airway obstruction. After local anesthesia, a 3-cm by 6-cm rectangle of skin was removed from the ventral surface of the neck, 3 cm distal to the cricoid cartilage. The sternothyrohyoideus muscles were clamped proximally and distally, then transected to expose the tracheal rings. The ventral third of four tracheal rings was dissected from the tracheal mucosa that was then incised in a double "Y." Two layers of suture were used to achieve mucocutaneous closure. Stomas healed without serious complications;...
Mair TS, Stokes CR, Bourne FJ.Lavage procedures were used to obtain samples of respiratory secretions from the nasal cavity, trachea, bronchi and bronchoalveolar level of apparently normal conscious horses, and the cellular composition of the lavage fluids was assessed. There was a progressive increase in total cell count of the secretions obtained from the upper to the lower respiratory tracts. Nasal lavage fluid was composed chiefly of epithelial cells, whereas tracheal, bronchial and bronchoalveolar fluids contained higher proportions of macrophages, lymphocytes and neutrophils. Eosinophils and mast cells were identifie...
Kähn W, Palmer J, Vaala W.Various techniques for support and control of respiration in neonatal foals are described. It is crucial to evaluate respiration through frequent arterial blood gas analysis. Details for blood sampling from the metatarsal arteries and interpretation of results are provided. Typical diseases in newborn foals, which cause hypoxemia and/or hypercapnia and can be indications for respiratory support are apnea, hypopnea, pulmonary atelectasis, surfactant deficiency, meconium-, fetal fluid- and milk aspiration, maladjustment syndrome, cardiovascular abnormalities, anemia, airway obstruction, compromi...
Charlton C, Tulleners E.Two male racehorses (1 Standardbred, 1 Thoroughbred) were examined because of intraluminal cervical tracheal lesions, located 60 to 70 cm from the nares. A contact neodymium:yttrium aluminum garnet laser with a chisel probe attached to the fiber end was used to transendoscopically debride a nonhealing tracheal ulcer and to excise a pyogranulomatous mass. In both horses, the surgical sites healed quickly and the lesions did not redevelop.
Holcombe SJ, Derksen FJ, Stick JA, Robinson NE.To determine the effect of bilateral hypoglossal and and glossopharyngeal nerve block on epiglottic and soft palate position and tracheal and pharyngeal pressures in exercising horses. Methods: 5 Standardbreds. Methods: Tracheal and pharyngeal pressures were measured in 5 Standardbreds exercising at the speed at which the horses achieved 50, 75, and 100% of maximal heart rate after bilateral hypoglossal and glossopharyngeal nerve block and without nerve block. Nerve block was achieved by injection of 1 to 2 ml of 2% mepivicaine hydrochloride between the glossopharyngeal and hypoglossal nerves,...
