We perform a large number of upper respiratory tract surgeries each year in conjunction with Mr. J G Lane BVetMed, DESTS, FRCVS, (RCVS Specialist in Equine Surgery). These operations are indicated in horses where abnormalities of the upper respiratory tract (larynx, pharynx, epiglottis etc) are affecting the airflow into the lungs and so limiting performance.
Diagnosis of these conditions is usually via a combination of loss of performance, often a respiratory noise and endoscopy of the upper respiratory tract. For definitive diagnosis overground endoscopy may be required which we offer at the hospital. The various procedures are carried out under general anaesthesia in our operating theatre.
Racehorse undergoing overground endoscopy
The majority of procedures that we perform are aimed at treating the two most common abnormalities; Recurrent laryngeal neuropathy (paralysis of the left side of the larynx) and Dorsal displacement of the soft palate (DDSP). Sometimes more than one problem may be present and so more than one procedure will be performed at the same time.
Recurrent Laryngeal Neuropathy
Depending on the severity of the paralysis of the cartilage on the left side of the larynx and the exercise requirement of the horse this condition may cause a loss of performance and often causes an inspiratory noise and so affected horses are sometimes termed “roarers”. Mild cases will be treated by “Hobday” (ventriculocordectomy) surgery; removing the lining of the ventricles which vibrate to cause the noise along with the vocal cord. More severe cases may also require a “Tieback” (prosthetic laryngoplasty) where the paralysed cartilage within the larynx is fixed into a position that allows adequate airflow but at the same time without allowing food to enter the airway. While complications can occur, the overall success rate with these procedures is very good.
Grade 5 (Completely Paralysed) larynx. The left side of the larynx(right of picture) hangs across the entrance to the trachea obstructing the airflow.
In this condition the soft palate, which separates the mouth from the back of the nose, becomes dislodged from its normal position under the epiglottis. Various techniques are available which aim to stiffen the soft palate to help prevent this happening, we utilise a soft palate cautery technique most frequently. A more recent technique with a higher success rate (around 80%) is the “Tie-forward” which moves the larynx (and so epiglottis) forward forming a more secure seal between the soft palate and the epiglottis.
All of these procedures require a period of rest to allow healing, usually in the region of 4-5 weeks after which we recommend horses are gradually returned to work.
Contact the clinic for more details of investigations, procedures and costings.