A two-year-old Arabian gelding was referred to OSU Lois Bates Acheson Veterinary Teaching Hospital for possible guttural pouch infection. He presented for blood coming from his right nostril. The diagnosis of guttural pouch mycosis was confirmed with an upper airway endoscopic evaluation. (See Figure 1).
Guttural pouch mycosis is a serious and potentially fatal fungal infection. It is unknown why or how the fungal infection begins. The guttural pouch is an outpouching of the ear canals whose function is not completely understood. The infection causes inflammation and damage to blood vessels and nerves in the guttural pouch leading to the clinical signs. These include a bloody nasal discharge, swallowing difficulties, unusual head posture, head shaking and head shyness. If left untreated the fungus can erode into the carotid artery leading to a fatal hemorrhage.
The gelding returned to OSU Veterinary Teaching Hospital for treatment. Multiple methods of treatment have been used to treat guttural pouch mycosis from antifungal therapy to surgical procedures intended on depriving blood supply from the fungal organism. Computed tomography (CT scan) was done with intravenous contrast media in order to highlight and define the affected blood vessels. A two-centimeter aneurysm was identified in the right internal carotid artery. The following day he was placed under general anesthesia a second time for the placement of the vascular occlusion plugs in the internal carotid artery. Dr. Michael Huber exteriorized the common carotid artery so the aneurysm could be occluded using nitinol vascular occlusion plugs. These were placed by cardiologist Dr. David Sisson on either side of the aneurysm using fluoroscopy thus stopping blood flow past the aneurysm.
He went home three days following the procedure and is doing well at home. He will return to the hospital for a recheck in two months.
Finally, a special thanks to all the clinicians and technicians that contributed to his treatment for without the enormous effort by the cardiology service, radiology department, large animal surgery service, anesthesia department, and large animal internal medicine service it would not have been successful.
Special thanks to John Schlipf, Jr., DVM, DACVIM-Large Animal Internal Medicine; David Sisson, DVM, DACVIM-Cardiology; Tom Riebold, DVM, DACVA-Anesthesia; Mike Huber, DVM, MS, DACVS-Large Animal Surgery; Susanne Stieger-Vanegas, Mag. vet. med., Dr. med. vet., DECVDI-Radiology, PhD; Jason Weist, Computed Tomography Technician.
Melissa Esser, DVM
Oregon State University Large Animal Internal Medicine Resident