The diagnostic yield of advanced imaging in dogs with Horner's syndrome presenting with and without additional clinical signs: A retrospective study of 120 cases (2000-2018).

Purpose: To evaluate the diagnostic yield of advanced imaging in dogs with Horner's syndrome (HS) both with and without additional clinical signs.

Methods: Retrospective review of clinical records from a UK referral hospital (2000-2018). Cases were excluded if HS was trauma- or surgery-related and if no advanced imaging with MRI or CT was performed.