HBC dog with dropped elbow and no sensation suggests which injury?

• A. Radial nerve palsy
• B. Ulnar nerve injury
• C. Brachial Plexus Avulsion
• D. Median nerve injury

Answer: (C)

Localize the injury by looking at the pattern of motor and sensory loss. Dropping the elbow shows loss of elbow extension, which points to disruption of the radial nerve’s function to the triceps. When that motor deficit comes with complete absence of sensation in the entire limb, it indicates a proximal lesion that affects multiple nerves—most often a brachial plexus injury. Brachial plexus avulsion occurs when the nerve roots are torn from the spinal cord after a high-energy trauma like a hit-by-car, leading to flaccid paralysis of the forelimb and anesthesia of the limb. This combination fits brachial plexus avulsion best. Isolated radial nerve palsy can cause elbow drop but typically has some sensory input remaining rather than complete limb anesthesia, while injuries to the ulnar or median nerves cause different, more localized motor deficits and do not produce the global limb anesthesia described.