LADIS Case of the Month - September/October 2012

Submitted by: Dr. Russ Tucker, Washington State University

History: 14-year-old quarter horse mare presented for colic of one day duration. The horse had been previously diagnosed with vestibular disease two years ago. Radiography at that time revealed an irregular contour of the right stylohyoid bone and sclerosis of the right petrous temporal bone. The radiographic findings suggested a healed right stylohyoid bone fracture with remodeling of the petrous bone. No active infection was discovered on endoscopy. Since the original diagnosis of vestibular disease there had been significant improvements in the clinical signs with conservative management although residual deficits (minor head tilt to the right) remained.

The clinical signs associated with the colic resolved within one day of hospitalization with supportive care. The horse’s appetite returned to normal and she was passing normal feces. However her right head tilt became more pronounced since her presentation to the hospital. Neurologic examination revealed a right-sided head tilt with a grade 1 ataxia in the hindlimbs. No other neurologic deficits were noted. It was recorded that the horse demonstrated “cribbing behavior” in the stall.

Due to the progression of the head tilt, radiography and endoscopic examination of the guttural pouches was performed. Endoscopy revealed an enlarged right stylohyoid bone with no evidence of active infection within the guttural pouch. The left stylohyoid bone and guttural pouch was judged to be normal.

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