Correcting Equine Nasal Collapse Caused by Nerve Damage

Damage to the dorsal buccal branch of the facial nerve can result in nasal collapse and difficulty breathing.

Photo: Courtesy Dr. Rubén Anguiano

By Rubén Anguiano, DVM, MSc, University of Guadalajara, México, WEVA Regional Ambassador

To be able to breathe, a horse’s nostrils and nasal passages must open and close normally. The dorsal buccal branch of the facial nerve innervates these important structures. Thus, neurologic dysfunction can result in nasal collapse and difficulty breathing.

Nasal Collapse Etiology

Neurologic dysfunction of the facial nerve’s dorsal buccal branch can occur for a variety of reasons, including:

  • Accidental head trauma;
  • Brutality and mistreatment;
  • Lack of proper head protection during general anesthesia in lateral recumbency; and
  • Iatrogenic conditions, or those inadvertently caused by veterinary care. For example, the veterinarian might accidentally damage the nerve trunk during tooth extractions or procedures to correct overbites or repair maxillary (upper jaw or cheek) fractures.

Case Report

An 18-month-old Andalusian colt developed severe respiratory distress because he could not open his nostrils properly during inspiration. A veterinary exam revealed that the lateral side of the alar cartilage (a ring of cartilage that holds the nostrils open during inhalation) had collapsed inside the nose. Veterinarians learned that the colt had been tied to a post while wearing a bosal during training. At some point, he suffered trauma from the bosal and a martingale, which had resulted in the bilateral nasal passage compression. His caretakers detected his respiratory distress the next day.

Medical treatment—which included non-steroidal anti-inflammatory, antibiotic, and antineurotic drug administration, along with physical therapy—was unsuccessful. As such, veterinarians performed a tracheostomy, which involves surgically creating an opening through the skin into the trachea to allow for insertion of a breathing tube, and left the tube in place for 30 days. However, when the veterinarians removed the tube, the breathing issues returned.

Veterinarians finally elected to enlarge the nostrils permanently suturing the alar cartilage to the nearby tendon of the Levator nasolabialis muscles, which aid in lifting the upper lip and dilating the nostril. They used No. 2 polypropylene suture material and a horizontal mattress pattern for the procedure. Postoperative management included administering penicillin G procaine for five days, gentamicin for five days; phenylbutazone every 12 hours for 10 days, and proper wound management.

Following the procedure, the colt’s collapsed nasal passages dilated immediately, his respiratory capacity returned, and he once again tolerated exercise.

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