Topic:Endoscopy
Endoscopy in horses refers to a diagnostic procedure that involves the use of an endoscope, a flexible tube equipped with a camera and light, to visually examine the interior surfaces of equine organs and tissues. This technique is commonly employed to investigate conditions affecting the respiratory tract, gastrointestinal tract, and other internal structures. Endoscopy allows for direct visualization and assessment of abnormalities such as lesions, obstructions, or inflammation. It can also be used to obtain biopsies or remove foreign bodies. This page compiles peer-reviewed research studies and scholarly articles that explore the applications, methodologies, and clinical relevance of endoscopy in equine medicine.
Naturally occurring persistent and asymptomatic infection of the guttural pouches of horses with Streptococcus equi. During an outbreak of strangles on a farm with approximately 1500 horses, the spread of Streptococcus equi infection was monitored by repeated nasopharyngeal swabbing and culture. In order to control the infection and prevent new introductions of strangles on to the premises, a system of quarantine and swabbing of cases and all incoming animals was instituted. Long-term carriage of the organism was detected in four clinically healthy convalescent animals, and in two of 350 new ponies; it persisted for between seven and 39 months, but it was detected only intermittently by the culture of swabs ...
Cardiorespiratory responses to exercise in horses with different grades of idiopathic laryngeal hemiplegia. The relationship between different grades of laryngeal function, as assessed by endoscopy at rest, and the measurements of indices of gas exchange and exercise capacity was assessed during a standardised treadmill exercise test in 149 horses. Horses with abnormalities other than idiopathic laryngeal hemiplegia (ILH) were excluded from the study and laryngeal function was graded according to an established system. There were no significant differences in age, weight, maximum oxygen uptake, maximum carbon dioxide production, maximum respiratory exchange ratio, maximum oxygen pulse and run time b...
Upper respiratory causes of exercise intolerance. The respiratory system is a frequent cause of exercise intolerance in performance horses. Labored breathing, fatigue during performance, and prolonged recovery after exercise are common complaints. Inadequate fitness level and diseases of the cardiovascular system are differential diagnoses that share these complaints and should be ruled out. Generation of increased airway noise is a clinical sign that implicates the upper respiratory system. A careful history from the owner and endoscopy of the upper airway are the most useful diagnostic tools. Endoscopy during exercise on a treadmill is indi...
Lower respiratory tract disease. Lower respiratory tract disease is an important source of poor performance and exercise intolerance in racehorses and middle-aged sport horses. Horses that perform high-intensity exercise are predisposed to development of infectious and noninfectious respiratory disease. Diagnostic aids for investigation of lower respiratory tract disease include thorough thoracic auscultation with rebreathing, endoscopic examination, bronchoalveolar lavage (BAL), and thoracic radiographic examination. The therapeutic approach for horses with lower respiratory tract diseases often can be directed by cytologic ...
Diagnostic approach to exercise intolerance in racehorses. The diagnostic approach to the exercise intolerant racehorse depends on sound, fundamental steps to allow complete examination of the entire horse in a logical, time-efficient fashion. Availability of referral diagnostic modalities should not overshadow the need for collecting a clinical history or performing a complete physical examination. The diagnostic approach to exercise intolerance can be divided into a few basic steps. The first step, conducted without the horse, is a thorough discussion about the horse with the trainer and/or owner. Many clinical histories are complex and therefore fo...
Efficacy of prosthetic laryngoplasty with and without bilateral ventriculocordectomy as treatments for laryngeal hemiplegia in horses. To evaluate the efficacy of prosthetic laryngoplasty with and without bilateral ventriculocordectomy for treatment of experimentally induced left laryngeal hemiplegia (LLH). Methods: 15 adult Standardbreds. Methods: Horses were allotted to 3 equal groups. Sham operation (group 1), prosthetic laryngoplasty (group 2), or prosthetic laryngoplasty with bilateral ventriculocordectomy (group 3) was performed after induction of LLH. Upper airway function testing was performed prior to left recurrent laryngeal neurectomy (LRLN), 14 days after LRLN, and 60 and 180 days after surgical treatment. Measure...
Pulmonary vascular pressures of exercising thoroughbred horses with and without endoscopic evidence of EIPH. Exercise-induced pulmonary hemorrhage (EIPH) is a common occurrence in racehorses. The objective of this study was to compare pulmonary vascular pressures of healthy Thoroughbred horses with and without postexertion endoscopically detectable fresh blood in the trachea. The nasopharynx, larynx, and trachea (down to the carina) of horses were examined weekly with an endoscope 55-60 min postexertion, and the diagnosis of EIPH was confirmed by the presence of fresh blood in the trachea. Measurements of heart rate and right atrial, pulmonary arterial, and pulmonary arterial wedge pressures were mad...
Factors associated with gastric lesions in thoroughbred racehorses. Gastroscopic examinations were performed on 67 Thoroughbred horses in training at a race track and repeat examinations performed in 35 horses, 2 to 3 months later. Horses were age 2-9 years and included 16 two-year-olds, 32 three-year-olds and 19 horses > or = 4-years-old. Forty-two of the 67 horses had raced within the 2 months before the initial examination and the remaining 25 horses were in training. Sixty-two of the 67 horses (93%) had one or more lesions present in the gastric mucosa and lesions were present in all of the 42 horses that had raced. Thirty-two of the 35 horses, examined...
Instrumentation and techniques in transendoscopic upper respiratory tract laser surgery. Transendoscopic laser surgery provides equine surgeons with a safe, reliable, and minimally invasive method of performing many surgical procedures in the upper respiratory tract. Although the Nd:YAG laser has proven efficacy, other newer lasers such as the diode and holmium: YAG lasers may prove to be useful tools for equine upper respiratory tract surgery. Long grasping forceps and a high quality fiberoptic or video endoscope are critical components necessary for performing transendoscopic laser surgery. For many of the most common upper respiratory tract abnormalities, a laryngotomy can be e...
Laryngospasm, dysphagia, and emaciation associated with hyperkalemic periodic paralysis in a horse. An 18-month-old Quarter Horse gelding was examined because of weight loss and dysphagia of 1 month's duration. Clinical signs included lethargy, dehydration, ptyalism, and probable aspiration pneumonia. Severe dyspnea and cyanosis were evident after mild exercise. Endoscopy revealed laryngospasm and pharyngospasm. Because clinical signs and endoscopic findings were suggestive of hyperkalemic periodic paralysis (HPP), acetazolamide treatment was instituted. Marked improvement was observed within 48 hours. The horse was determined to be homozygous for HPP. It is likely that this horse's dysphagi...
Obstructive pulmonary disease in 18 horses at summer pasture. The clinical features of 18 cases of summer pasture associated obstructive pulmonary disease were reviewed. The horses had signs of obstructive pulmonary disease (expiratory dyspnoea, wheezing and crackling lung sounds and coughing) during the spring, summer or autumn while they were kept permanently at grass with no access to hay or straw, for at least two consecutive years. In nine cases there was a seasonal incidence with the disease occurring during April and May. Eleven of the horses were affected by bouts of severe dyspnoea. Eleven of the horses also suffered from chronic obstructive pul...
Nasopharyngeal conidiobolomycosis in a horse. Nasopharyngeal conidiobolomycosis caused by Conidiobolus coronatus was diagnosed in a horse after endoscopic and histopathologic examinations of a biopsy specimen. The fungal lesions in the nasopharynx were substantially reduced in size after intralesional injection of amphotericin B through the biopsy channel of a videoendoscope in combination with i.v. administration of sodium iodide and oral administration of potassium iodide during a 2-month period. Endoscopy performed 15 months after initial examination revealed regression of the granulomatous masses in the nasopharynx and complete disapp...
Endoscopy of the auditory tube diverticula in four horses with otitis media/interna. Endoscopic examination of the auditory tube diverticula was a diagnostic aid in the evaluation of 4 horses with otitis media/interna and associated osseous changes of the stylohyoid and petrous temporal. One of the horses was examined because of persistent head shaking; the other 3 were examined because of an acute onset of facial and vestibulocochlear nerve dysfunction. Proliferative lesions involving the petrous temporal bone and proximal portion of the stylohyoid bone were identified endoscopically in all 4 horses. Endoscopy is a noninvasive procedure that provides an alternative to skull r...
Unilateral choanal atresia in a foal. A 4-month-old Thoroughbred foal was examined because of a history of exercise intolerance and lack of airflow from the right nostril since birth. Endoscopy of the airways revealed complete membranous obstruction of the right nasal passage at the level of the nasopharynx and marked narrowing of the caudal aspect of the right ventral meatus. Unilateral choanal atresia was diagnosed. Laser ablation of the obstructing tissues was attempted through a videoendoscope. Scar tissue occluded the right nasal passage at follow-up examination 7 weeks later. Intranasal resection, using laparoscopic instrume...
Sternothyrohyoideus myectomy or staphylectomy for treatment of intermittent dorsal displacement of the soft palate in racehorses: 209 cases (1986-1991). The efficacy of sternothyrohyoideus myectomy (SM) and staphylectomy as treatments for intermittent dorsal displacement of the soft palate was evaluated in 209 racehorses (126 Thoroughbreds, 83 Standardbreds). The 2 most common complaints were respiratory tract noise (75% of horses) and exercise intolerance (51% of horses). Stopping, defined as the inability to finish the race at racing speed, was reported in 40% of the horses. Endoscopy at rest revealed evidence of abnormal epiglottic anatomy (hypoplasia or flaccidity) in 51% of the horses and abnormal soft palate function in 36% of the horses...
Prevalence of upper respiratory tract disorders detected with a flexible videoendoscope in thoroughbred racehorses. A total of 350 thoroughbred racehorses found clinically as having coughs or abnormal breath sounds underwent endoscopic examination of the upper respiratory tract at rest. As a result, abnormal endoscopic findings were obtained in all horses, demonstrating that thoroughbred racehorses with a clinical abnormality in the respiratory system necessarily had disorders in the upper respiratory tract. Whereas 11 types of disorder were observed, a combination of three different types of disorder were found in the highest frequencies in 3-, 4- and 5-year-old horses (27.8%, 29.2% and 29.7%, respectively...
Measurement of upper airway pressures in exercising horses with dorsal displacement of the soft palate. To determine whether abnormal airway pressures have a role in development of dorsal displacement of the soft palate (DDSP), measurements of tracheal and pharyngeal pressures were correlated with nasopharyngeal morphology in exercising horses. Exercising videoendoscopy and measurement of tracheal and pharyngeal pressures were used in 14 clinically normal horses and 19 horses with intermittent DDSP. The pressure signals were superimposed on the videoendoscope image, and both images were saved simultaneously on a videocassette for slow motion analysis to determine the instant displacement occurre...
Endoscopy of the upper respiratory tract during treadmill exercise: a clinical study of 100 horses. Endoscopy of the upper respiratory tract was performed in 100 horses during high speed treadmill exercise. Reasons for endoscopy were a history of an abnormal noise during exercise in 75 horses, poor performance in 17 horses and to evaluate the results of upper respiratory tract surgery in 8 horses. Of the 75 horses with a history of an abnormal noise during exercise the cause was determined in 67 (89%). Endoscopic abnormalities were detected at rest in 40 of these 75 horses (53%). In these 40 horses, a similar diagnosis as to the cause of the abnormal noise was made at rest and during exercis...
Radiographic and endoscopic study of horses performing an oral based stereotypy. There is confusion in the veterinary literature concerning the definition of oral based stereotypies in the horse. This study reports the use of fluoroscopy and endoscopy during cribbiting/wind-sucking in afflicted horses. This permitted observations of movements of the pharyngeal and oesophageal tissues and of the air column within during the stereotypic behaviour. The findings reported show that the sequence of events during crib-biting/wind-sucking is not related to deglutition and that air is not swallowed to the stomach. Transient dilation of the upper oesophagus was recorded and the char...
Epiglottitis in horses: 20 cases (1988-1993). Epiglottitis was diagnosed and treated in 20 horses (13 Thoroughbreds and 7 Standardbreds) over a 5-year period. Eighteen horses were used for racing, and 2 Standardbreds were broodmares. Primary clinical signs were exercise intolerance, respiratory noise, and coughing. The most common endoscopic diagnosis made by referring veterinarians was epiglottic entrapment (11 horses). In 19 horses, endoscopic evaluation at admission revealed mucosal ulceration and thickening of the lingual surface of the epiglottis. Other endoscopic findings included dorsal displacement of the soft palate (14 horses), ...
Equine model of inducing ulceration in alimentary squamous epithelial mucosa. Ulceration of the gastric squamous epithelial mucosa was induced in 10 horses using a feeding protocol previously shown to expose the gastric mucosa to repeated periods of high acidity. The feeding protocol consisted of alternating feed deprivation with free access to hay. Over a period of seven days, each horse was provided hay for 84 hr and deprived of hay for 84 hr. Hay was never withheld for longer than 24 hr at a time. Gastroscopy was performed on each horse at the beginning of the protocol after 12 hr of feed deprivation, and after a total of 36 hr, 60 hr, and 84 hr of feed deprivation. ...
A survey of exercise-induced pulmonary haemorrhage in Quebec standardbred racehorses. Sixty Standardbred horses, aged 3 to 10 years, were examined endoscopically for exercise-induced pulmonary haemorrhage (EIPH) 1 h after racing, on at least 3 occasions. Racing time, finishing position and post exercise venous lactate concentrations were also recorded. Horses positive for tracheal blood on endoscopy were classified as having either grade 1 EIPH (one or a few spots of blood in the trachea), or grade 2 (stream of blood). Air temperature, relative humidity and air pollutant levels were recorded on each examination day. Of the 60 horses, 52 (87%) were EIPH-positive on at least one ...
Removal of inspissated purulent exudate from the ventral conchal sinus of three standing horses. Primary paranasal sinusitis, complicated by inspissated purulent exudate in a ventral conchal sinus, was diagnosed in 3 horses. Partial nasal obstruction, caused by axial deviation of the ventral concha, was detected endoscopically in 2 of the horses. A mass, dorsal to the maxillary molars, was detected via a lateral radiographic view of the skull of 3 horses and on the dorsoventral view of 1 of the horses. Inspissated purulent exudate was removed from the ventral conchal sinus of the horses via trephination of the conchofrontal sinus and penetration of the caudal wall of the ventral conchal s...
Evaluation of the thoraco-laryngeal reflex (‘slap test’) as an aid to the diagnosis of cervical spinal cord and brainstem disease in horses. A study was conducted over a 12 month period to assess the specificity and sensitivity of the 'slap test', using endoscopic evaluation, in the detection of cervical spinal cord and caudal brainstem lesions in horses. Fifteen ataxic horses were subjected to the 'slap test' and subsequently examined post mortem. Twelve out of the 15 had histopathological lesions consistent with their clinical signs. Thirteen horses with no history of neurological dysfunction and no histopathological evidence of cervical spinal cord or brainstem disease were used as controls. The laryngeal adductory responses exh...
Transnasal incision of restrictive nasopharyngeal cicatrix in three horses. Three horses were found to have an extensive nasopharyngeal cicatrix that was responsible for respiratory impairment. The cicatrization was diagnosed by use of endoscopy during evaluations of the horses for inspiratory stridor. All 3 horses were treated by endoscope-guided transnasal incision of the cicatrix and were able to resume their previous activities.
Endoscopic anatomy and map of the equine bronchial tree. To develop a bronchoscopic map of the equine respiratory tree, the major airways of the lungs of 6 healthy Thoroughbred horses were systematically explored with a flexible fibreoptic endoscope through a tracheostomy while the horses were sedated in stocks. With the carina as the reference point, measurements were made of distances to the branches of the major airways using markers on the shaft of the endoscope. All branches were explored until the narrowing of their diameters prevented further advancement of the endoscope. Positions of origins of branches from the parent bronchus were recorded...
Transendoscopic contact neodymium:yttrium aluminum garnet laser treatment of tympany of the auditory tube diverticulum in two foals. Tympany of the auditory tube diverticulum was treated in 2 Standardbred foals by fenestrating the median septum, using an endoscopically placed Nd:YAG laser. Recurrence in 1 foal was treated by enlarging the fenestration, using a modified Whitehouse approach, and the pharyngeal opening of the auditory tube. Use of the Nd:YAG laser eliminates the risk of inadvertent cranial nerve damage associated with incisions into the auditory tube diverticulum. The procedure can be performed with the horse sedated or anesthetized. Clinical signs can recur in the fenestration heals closed or if the condition...
Transendoscopic electrocautery-induced gastric ulcers as a model for gastric healing studies in ponies. The ponies were apparently healthy and 6-20 months of age. In Study 1, gastric lesions were created by transendoscopic electrocautery in the non-glandular gastric mucosa, adjacent to the margo plicatus in 9 ponies which were then treated with water, 12 mg cimetidine HCl/kg bwt or 18 mg cimetidine HCl/kg bwt per os every 12 h for 35 days. In Study 2, gastric lesions were similarly induced in 9 ponies in the non-glandular mucosa and also in the glandular mucosa just below the non-glandular lesion on the greater curvature of the stomach. The ponies were treated with water, 8 mg cimetidine/kg bwt ...
Squamous cell carcinoma of the larynx and pharynx in horses. Medical records were reviewed for 11 horses with squamous cell carcinoma of the larynx and/or pharynx. The average age at presentation was 15.3 years. No breed or sex predilection was present. At presentation, 6 of 11 horses were dyspneic and 4 horses had inspiratory stridor. Endoscopy was performed in all cases and was more useful in demonstrating a mass in the laryngopharyngeal region than laryngeal or guttural pouch radiography. Surgical excision was attempted in 3 horses and in 1 horse alleviated clinical signs for 4 months. Ten horses were euthanatized and 1 horse died. Results of this st...
Lack of residual lung damage in horses in which Rhodococcus equi-induced pneumonia had been diagnosed. The effect of prior Rhodococcus equi-induced pneumonia on pulmonary health was investigated in 5 horses (< 24 months old) using endoscopy, radiography, hematologic and bronchoalveolar lavage analyses, and pulmonary function testing. Rhodococcus equi-induced pneumonia had been diagnosed in principal horses when they were foals. Diagnosis was based on positive results of transtracheal aspiration and thoracic radiography at the time of initial clinical examination. Results of reevaluation of the respiratory system of these horses (R+) were compared with those of 5 age-matched healthy horses (R...