Our flexible fiber optic endoscope is helpful for evaluating the airway of the horse, including the larynx, sinuses, guttural pouches and trachea. Flexible endoscopy is also useful for diagnosing problems of the bladder and uterus.
The picture above was taken through the flexible endoscope showing the characteristics of the disease condition. The first thing to note is the asymmetry of the structure.
The red outline circumscribes the horse's right corniculate cartilage, sometimes referred to as the "flapper" because it moves ("flaps") inward during vocalization and during swallows and outward during exercise. Perhaps more pertinent to the disease is that the cartilage is flaccid and free to flap across the larynx during inspiration. The red line shows the normal position of the right cartilage when the horse is at rest.
Some conditions we commonly treat with the help of endoscopy...
Laryngeal hemiplegia is a common disease of horse's upper respiratory tract. It is commonly referred to as roaring because of the distinctive noise produced by affected horses when they exercise. The disease's cause is unknown. We know a lot about the epidemiology of the disease and there are several theories about causes.
The disease is much more common in large breed horses, and it is very rare in ponies. Among the large breeds, it affects larger individuals more often, so apparently size is connected to development of the condition. The disease results from loss of nerve function to the muscle that opens the larynx. The larynx needs to open to accommodate for high airflow rates needed during exercise. Importantly, the larynx is the narrowest part of the airway at rest, and it increases in cross sectional diameter more than any other place in the airway. So, when affected by this disease, a horse looses a substantial amount of its ability to inhale an adequate volume of air during exercise. For horses that compete at speed it is a very debilitating disease.
Ethmoid hematoma is a progressive and locally destructive disease of horses. It is indicated by a mass in the paranasal sinuses, that resembles a tumor but is not neoplastic by any means. The origins and causes of the ethmoid hematoma are generally unknown. Large hematomas usually start within the ethmoid labyrinth, and smaller ones tend to begin on the sinus floor.
The hematoma usually extends into the nasal passage. A growing hematoma causes pressure necrosis of the bone surrounding the hematoma, but only on rare occasions does it cause facial distortion. It is most commonly seen in horses older than 6 years. Mild, persistent, spontaneous, intermittent, and unilateral epistaxis is the most common sign clinically.
Diagnosis of the condition is best suited to endoscopy; the lesion can be seen extending into the nasal passages on endoscopic examination and can be demonstrated on radiographs. Further elucidation can be obtained with MRI or CT in cases which are more widespread or invasive.
Treatment most commonly involves the removal of the complete lesion during a single procedure, via the frontonasal bone flaps; recurrence is likely. Ablation treatment with an Nd:YAG laser looks to be a possibility for permanent removal. There has been some success using intra-lesional injections of formalin, performed via endoscopy.
Arytenoid chondritis is a performance-limiting condition in horses. The underlying problem is a primary infection in the body or corniculate process of 1 or both arytenoid cartilages of the larynx. When chronic inflammation or abscessation may deform and permanently immobilize the affected cartilages, partial arytenoidectomy is indicated. Before that point, the process can be arrested by local debridement or drainage of the lesions, which has traditionally been accomplished by laryngotomy with the horse under general anesthesia. Infections of the arytenoid cartilages with granulomas and abscesses can be effectively treated in the standing horse by using the diode laser administered by an endoscopically guided ventral stab incision in the cricothyroid membrane.