Paralaryngeal abscess with laryngeal hemiplegia and fistulation in a horse.

The research focused on a case of a three-year-old Thoroughbred horse which presented with a paralaryngeal abscess accompanied by laryngeal hemiplegia and fistulation. The abscess was caused by Staphylococcus aureus, likely originating from oral trauma to the larynx. Despite successful surgical treatment, the prognosis for respiratory soundness was poor due to extensive laryngeal fibrosis.

Case Presentation

• The filly was brought to the clinic due to bilateral nasal discharge and swelling of the left laryngeal area. This young horse presented symptoms that aroused the concern of auditory and respiratory health.

Diagnosis

• An endoscopic examination revealed an enlarged left arytenoid cartilage, left laryngeal hemiplegia, and drainage of purulent material into the lumen of the larynx. This was a critical diagnostic step, as it allowed for the discovery of the left laryngeal paralysis and purulent drainage, indicating infection.
• Radiographs further showed a large fluid and gas-filled cavity overlying the caudal larynx and cranial trachea. This imaging showed visible abscesses, which further confirmed the diagnosis.

Treatment

• Surgical drainage and debridement of the abscess led to complete healing by secondary intention. Although the surgery initially provided encouraging results, it was unable to undo all of the damage done by the infection.
• A laryngeal ventriculectomy was performed to treat the left laryngeal hemiplegia. This surgical procedure involves the removal of part of the larynx to help alleviate paralysis.

Prognosis and Etiology

• Despite the treatment, a grave prognosis was given for respiratory soundness due to the extensive laryngeal fibrosis. It means that permanent damage was caused to the larynx, hampering the horse’s ability to breathe normally.
• The cause of the Staphylococcus aureus abscess is unknown, but it may have originated from oral trauma to the larynx. This underscores the potential risk that even seemingly minor oral injuries pose for developing serious infections in this sensitive area.