Racing Performance in 72 Racehorses Treated with Prosthetic Laryngoplasty for Laryngeal Hemiplegia

The purpose of this study was to compare racing performance before and after prosthetic laryngoplasty for treatment of laryngeal hemiplegia in inexperienced (horses without at least one start before surgery) and experienced (horses with at least one start before surgery) Thoroughbred and Quarter Horse racehorses. Medical records of 54 Thoroughbred and 18 Quarter Horse racehorses or horses intended for racing treated with prosthetic laryngoplasty and unilateral ventriculectomy for laryngeal hemiplegia were reviewed. Signalment, age at the time of surgery, resting endoscopic grade of laryngeal function, surgical procedure, and type of suture were recorded. Median performance index (PI), earnings, distance, and Beyer speed figure (BSF) per start for three races before and after surgery were compared, and factors associated with improved postsurgical performance were evaluated. Seventy-three percent of horses that had not raced before surgery and 84% of horses that competed in at least one race before surgery were able to return to racing after surgery. Fifty-nine percent and 27% of Thoroughbreds and Quarter Horses, respectively, were able to improve their PI after surgery. Sixty-two percent and 20% of Thoroughbreds and Quarter Horses, respectively, significantly increased their distance after surgery. Additionally, 61% and 66% of racehorses were able to increase their earnings and BSF after surgery, respectively. Horses treated with laryngoplasty and unilateral ventriculectomy have a good prognosis for return to racing. Inexperienced racehorses have a better prognosis for improvement after surgery than do experienced racehorses. Thoroughbred racehorses have a better success rate than Quarter Horse racehorses.     

The Effects of Anesthesia on Laryngeal Function and Laryngeal/Pharyngeal Trauma in the Horse

Laryngeal paralysis in horses has been reported after inhalational anesthesia and can result in significant morbidity/mortality. The cause of the condition is unclear. The objective of this study was to examine the effects of a standardized anesthetic protocol on laryngeal function and laryngeal/pharyngeal trauma in the peri-anesthetic period in a prospective study. A 30- to 60-second digitalized video clip of laryngeal movement from a standardized endoscopic view was recorded at five time points: before sedation, post-sedation, post-induction, immediately after recovery to standing, and at 24 hours after recovery. A standardized anesthetic regimen was used in all cases. Video clips were randomized and evaluated by two blinded assessors. Each assessor scored each clip for laryngeal function and trauma using previously validated scoring systems. Agreement between assessors was calculated using the mean of the five time-specific weighted kappa statistics. Post-anesthesia laryngeal function and trauma scores were compared with initial scores using the Wilcoxon signed rank test with Bonferroni adjustment. Spearman's rank coefficient was used to assess correlation between trauma and function scores and between anesthetic duration and laryngeal function and trauma scores.There was no significant effect of anesthesia on laryngeal function. Trauma scores were not significantly higher after tracheal intubation. The trauma scoring system requires further validation. There was no correlation between higher trauma scores and laryngeal function or duration and laryngeal function or trauma.Further work is required to evaluate other variables that may affect laryngeal function after anesthesia, using a larger number of horses with varying degrees of laryngeal dysfunction.     

Laryngeal Hemiplegia in Draft Horses A Review of 27 Cases

Case records of 27 draft horses with laryngeal hemiplegia were reviewed. Twenty-one horses were treated by ventriculectomy with or without prosthetic laryngoplasty, and 17 owners were contacted to determine the results. Fifteen horses improved after surgery and were able to perform to the owners' expectations. Performance improved significantly and hospitalization was shorter after ventriculectomy alone. Results of this study indicate that the clinical signs of exercise intolerance and excessive inspiratory noise associated with left laryngeal hemiplegia in draft horses can be treated successfully by ventriculectomy without prosthetic laryngoplasty.     

Acute Life-threatening Laryngeal Dysfunction in a Draft Horse Recovering from General Anesthesia: A Case Report

A 13-year-old Shire horse was anesthetized for an elective orthopedic procedure. During recovery from anesthesia, the occurrence of severe acute dyspnea required a second anesthetic to allow endoscopy-guided nasotracheal intubation. Endoscopic findings were decreased mobility and swelling of the arytenoids with narrowing of the laryngeal aditus. Owing to a dislodgement of the nasotracheal tube during recovery, a third anesthetic was carried out to perform emergency tracheostomy. Recovery from the third anesthetic was long and the horse developed a post-anesthetic myopathy. The clinical conditions improved during the following 48 hours, and an endoscopic examination performed before discharge revealed unremarkable laryngeal function. It was hypothesized that mechanical stimulation of the trachea during the phases of intubation and extubation caused traumatic laryngeal dysfunction, and that draft horses might require additional care during the perioperative period.     

Laryngoplasty With or Without Ventriculectomy for Treatment of Left Laryngeal Hemiplegia in 230 Racehorses

Objective —The purpose of this study was to examine the influence of laryngoplasty on racing performance and to determine if any of the following variables had a significant effect on outcome: breed (Thoroughbred v Standardbred), endoscopic grade of laryngeal function, ventriculectomy versus no ventriculectomy, type of prosthetic suture used, and number of prostheses placed. Study Design —Retrospective study of laryngoplasty with or without ventriculectomy for treatment of left laryngeal hemiplegia in racehorses between 1986 and 1993. Animals or Sample Population —230 horses (174 Thoroughbreds, 56 Standardbreds). Methods —The medical records of racehorses or horses intended for racing were reviewed. Signalment, admitting complaints, physical examination findings, resting endoscopic grade of laryngeal function, type of prosthetic suture material used, number of prosthetic sutures placed, presence or absence of ventriculectomy, and postoperative complications were recorded. Results —Upper respiratory tract noise and exercise intolerance were the most common presenting complaints. Two horses had a laryngeal grade of 2, 109 horses a laryngeal grade of 3, and 119 horses a laryngeal grade of 4. Two double-strand braided polyester sutures were used in 147 horses, a single double-strand polyester suture was used in 49 horses, and a single double-strand nylon suture was used in 34 horses. Ventriculectomy was performed on 186 horses. The most common complication recognized during hospitalization was coughing in 50 horses. Telephone follow-up was obtained for 176 horses. For 168 horses, respiratory noise after surgery was decreased in 126 horses, the same in 28, and increased in 14. After hospital discharge, coughing occurred in 43 of 166 horses, and a nasal discharge occurred in 26 horses. Postoperative racing performance for 167 horses was subjectively evaluated by respondents as being improved in 69% of the horses. Overall owner satisfaction with the outcome after surgery was 81%. Of 230 horses, 178 raced at least one time after surgery. Overall, 117 horses raced three or more times before and after surgery, and 65 of these horses had improved performance index scores. None of the variables of surgical interest affected performance index scores. Conclusions and Clinical Relevance —Laryngoplasty with or without ventriculectomy allowed 77% of the horses to race at least one time after surgery, improved racing performance in 56% of the horses that completed three races before and after surgery, and improved subjectively evaluated racing performance in 69% of the horses.     

Carotenodermia in a Horse

This case report describes an 11-year-old Appaloosa gelding that was examined because of yellow–orange tinting of the skin of the muzzle, eyelids, sheath, anus, and perianal region without discoloration of the sclera or mucus membranes. The horse was reported to preferentially eat dandelions which were plentiful in the pasture. Physical examination was normal, except for the discolored skin. A serum chemistry panel was normal. Carotenodermia was suspected. Serum carotenoid concentrations were higher in the affected horse as compared with concentrations in two horses with depigmented skin of normal color that were on grass pasture in the same geographic area. The horse remained systemically healthy and the abnormal skin color had almost disappeared when he was examined 7 weeks later. Carotenodermia can occur in horses and can be differentiated from jaundice because the sclera remains unaffected. Veterinarians should be aware that the condition is benign and spontaneously resolves after stopping carotenoid intake.     

Blood Gas Tensions, Acid-base Status, Heart Rates, and Venous Profiles in Exercising Horses with Laryngeal Hemiplegia Before and After Corrective Surgery

The physiologic effects of exercise were studied in four horses with complete laryngeal hemiplegia. Right carotid arteries were surgically elevated to a subcutaneous position for percutaneous catheterization. Each horse was fitted with a device designed to obtain multiple arterial samples while the horse was exercised over a 1.6-km course. After each horse completed 10 test gallops, the laryngeal hemiplegia was treated using a laryngeal prothesis and ventriculectomy. The horses were then reconditioned, and the exercise test and sampling were repeated. Horses with laryngeal hemiplegia became acidotic, hypoxic, and hypercapnic compared to normal horses. Surgical treatment improved blood gas and acid-base status, but the values were not equivalent to those in normal horses similarly tested.     

Treatment of Coccidioidomycosis Osteomyelitis with ltraconazole in a Horse

Itraconazole, a tricyclic azole effective against a number of deep mycotic diseases, was used to treat a Quarter Horse filly with coccidioidomycosis. The horse was almost normal after 90 days of treatment. Five months after discontinuing itraconazole treatment, the filly had severe neck pain and neurologic signs from recurrence of coccidioidomycosis and was treated with itraconazole for an additional 6 months. Her clinical condition improved to almost normal and the filly has remained normal for 2 years. There was no evidence of drug toxicity.     

Pemphigus Foliaceus in a Horse

Abstract— A 3-year-old gelding was presented with a generalized chronic dermatitis characterized by erosions, ulcerations, crusting, scaling and widespread alopecia. The diagnosis of pemphigus foliaceus was based on history, clinical signs, histological lesions and immunohistological test results. Typical dermatohistopathological findings comprised intraepidermal acantholysis and cleft formation in both epidermis and hair follicle epithelium. Additionally, blisters and erosive lesions were found in the epithelia of various mucocutaneous junctions, the distal oesophagus and the oesophageal zone of the stomach. In formalin-fixed and paraffin-embedded tissues an immunoperoxidase technique was established to demonstrate deposits of the immunoglobulins G and M and the complement component C3 providing the opportunity to compare histological and immunohistological findings. Résumé— Un cheval hongre de 3 ans a été présenté avec une dermite chronique caractérisée par des érosions, des ulcères, des croutes, des squames et une alopécie très étendue. Le diagnostic de pemphigus foliacé reposait sur l'anamnèse, l'examen clinique et les résultats des examens histopathologiques et immunopathologiques. Les lésions histologiques typiques comprenaient des acantholyses intraépldermiques et la formation de fissures tant au niveau de lépiderme que des follicules pileux. En outre, des bulks et des érosions ont été retrouvées au niveau de différentes junctions cutanéomuqueuses et de la partie distalé de l'oesophage. Une technique d'immunopéroxydase sur tissus fixés au formol et en paraffine a été utilisée pour mettre en évidence des dépôts d'immunoglobulines G et M et de C3, permettant de comparer les observations histologiques et immunopathologiques. Zusammenfassung— Ein dreijähriger Wallach wurde mit einer generalisierten chronischen Dermatitis vorgestellt, die durch Erosionen, Ulzerationen, Krusten, Schuppen und ausgedehnte Alopezie gekennzeichnet war. Die Diagnose Pemphigus foliaceus stützte sich auf den Vorbericht, die klinischen Symptome, die histologischen Veränderungen und die Ergebnisse des immunohistologischen Tests. Die typischen histopathologischen Befunde umfaßten intraepidermale Akantholyse und Spaltbildung sowohl in der Epidermis wie im Epithel des Haarfollikels. Zusätzlich wurden Blasen und erosive Veränderungen in den Epithelien verschiedener mukokutaner übergänge, im distalen ösophagus und in der ösophagealen Zone des Magens gefunden. An formalinfixiertem und in Paraffin eingebettetem Gewebe wurde eine Immunoperoxidasetechnik durchgeführt, um die Ablagerungen von Immunglobulinen G und M und der Komplementkomponente C3 zu zeigen, wodurch die Gelegenheit bestand, histologische und immunohistologische Befunde zu vergleichen. Resumen Un caballo de tres anos fue presentado con una dermatitis crónica de tipo generalizado presentando erosiones, ulceraciones, costras y escamas epidérmicas, además de una alopecia generalizada. Una diagnosis de pémfigo foliáceo se basó en la historia y cuadro clínico, lesiones histológicas y resultados de tests inmunohistológicos. Los hallazgos dermato-histopatológicos típicos comprendieron acantolisis intraepidermica y la formación de indentaciones epidérmicas en ambos, epidermis y epitelio del folículo piloso. También se observó la presencia de vesículas y lesiones erosivas en el epitelio de las uniones mucocutaneas, asi como en áreas distales del esófago, y en zonas esofágicas del estómago. Después de la fijación en formol y sumersión en parafina de los tejidos, se utilizo la técnica de inmunoperoxidasa para la demonstratión de depósitos de inmunoglobulinas G y M, y el complemento C3, que proporcionó la oportunidad de comparar los hallazgos inmuno e histológicos.     

Laparoscopic Adhesiolysis in a Horse

Objective —The purpose of this report was to describe the use of laparoscopy as a method of treatment for abdominal adhesions in the horse.
Clinical Report —Unilateral ovariectomy for removal of a granulosa cell tumor was performed through a diagonal paramedian approach in a 14-year-old Arabian mare. Progressive incisional swelling and hemorrhage culminated in acute incisional dehiscence with herniation of ileum on the sixth postoperative day. Septic peritonitis that responded to parenteral antibiotic therapy was identified 7 days after hernia repair. Seven days later, the mare had signs of abdominal pain, and adhesions of small intestine to the paramedian incision were identified on rectal palpation. Transrectally assisted laparoscopic adhesiolysis was performed. No further complications occurred.
Clinical Relevance —Laparoscopic adhesiolysis may provide better observation of adhesions and reduced postoperative morbidity compared with laparotomy.     

Alopecia Universalis in a Horse

Abstract— Alopecia universalis was diagnosed in a 3-year-old brown Percheron mare. Clinical and histo-pathologic findings in this previously unreported condition in the horse are described.