Megaoesophagus in dogs with tick paralysis (Ixodes holacyclus)

Of 40 dogs which presented at varying stages of tick paralysis, 28 (70%) ha d megaoesophagus (MO) defined as oesophageal dilation on thoracic radiograp hs. Megaoesophagus was not related to the degree of appendicular weakness o r respiratory involvement. There was no association between MO and regurgit ation/vomiting or a reduced gag reflex. Tick attachment over the cervical o esophagus was not associated with MO. There was no link between MO and gend er or weight, however, dogs with MO were older than unaffected dogs. Radiog raphic resolution of MO often lagged behind complete clinical recovery.