Suprascapular nerve decompression for treatment of neuropathy in a bucking bull.

ABSTRACT

CASE DESCRIPTION A 3-year-old 639-kg (1,406-lb) American bucking bull was examined because of a 4-day history of right forelimb lameness that began after the bull sustained an injury to the right shoulder region while exiting the chute during a rodeo. CLINICAL FINDINGS: A 10 × 10-cm soft tissue swelling was present over the right shoulder region. Ultrasonographically, the contour of the scapular spine, bicipital bursa, bicipital tendon, and greater tubercle of the humerus appeared unremarkable; the swelling appeared to be a hematoma overlying the distal aspect of the scapula. No external wounds, palpable joint effusion, or swellings were noted on examination of the distal portions of the limbs. The bull developed atrophy of the supraspinatus and infraspinatus muscles with lateral abduction of the shoulder joint when walking. Electromyography revealed decreased innervation to the supraspinatus and infraspinatus muscles consistent with suprascapular neuropathy. TREATMENT AND OUTCOME: The suprascapular nerve was surgically decompressed by removing the entrapping hematoma and periosteum and performing a notch resection of the scapula; dexamethasone (40 mg) was administered prior to closure. The bull was discharged 5 days after surgery; no lameness was evident at the time of discharge. The owner was instructed to restrict the bull to a stall or small pen for 6 weeks. Four months after surgery, the muscle atrophy had substantially improved, and the bull returned to bucking. CLINICAL RELEVANCE Findings suggested that suprascapular neuropathy can develop in bulls secondary to injury and that suprascapular nerve decompression may improve nerve function, muscle atrophy, and gait.