Applied Anatomy of the Brachial Plexus in Domestic Animals and its Clinical Correlation with Forelimb Paralysis

The brachial plexus is the nerve network that supplies the entire thoracic limb, the shoulder girdle and part of the thoracic wall of domestic animals. Because it lies in the axilla, medial to the scapula and shoulder, it is highly exposed to traction, compression and fracture-related injury, and damage results in partial or complete forelimb paralysis. In dogs and cats it arises from C6–T1/T2, and in the horse, ruminants and pig from broadly similar segments, with minor species differences. Knowledge of its roots, course and the motor and cutaneous territories of its terminal nerves permits accurate localisation of lesions. Root avulsion after road traffic accidents, radial nerve paralysis, suprascapular neuropathy (Sweeney) in horses and nerve sheath tumours are the commonest clinical conditions. Early neurological assessment, electrodiagnostics and supportive care are the basis of management, while amputation is reserved for irreversible, self-traumatising limbs.