Diagnostic and Therapeutic Evaluations of Computed Tomography in Three Calves with Unilateral Otitis Media Treated with Ventral Bulla Osteotomy

This case report describes the clinical utility of computed tomography (CT) in preoperative evaluation of otitis media in three calves, each exhibiting unilateral head tilt and ear droop. Of the three animals examined by CT, right-sided and left-sided involvements of this disease could be diagnosed in two animals and one animal, respectively, as represented by the accumulations of hyperattenuating contents within the extended tympanic bulla. These cases were treated with a ventral bulla osteotomy, which was conducted between the sternothyroid muscle and the omohyoid muscle via an incision made caudally to the area of the thyroid cartilage. The postoperative outcome was satisfactory in one case. However, the remaining two cases showed unsatisfactory outcomes; one calf died on the 10th postoperative day, as it was already seriously ill. The other animal died suddenly during surgery, potentially due to stimulation of the vagus nerve. The use of CT could allow effective visualization of unilateral lesions, proving helpful for the recommendation of surgical intervention. Based on the unfavorable results in two cases, we note that to prevent surgical complications, the clinical applicability of CT such as the creation of severity criteria and development of imaging-assist procedure should be advanced.