Primary congenital jugular vein aneurysms are rare with only one prior report in a canine patient. Herein, we
describe an 18-week-old Flat Coated Retriever dog in which ultrasound was used to diagnose a primary
congenital external jugular vein aneurysm with concurrent dilatation of the internal jugular vein. The aneurysm
was successfully removed and the dog remains disease free 24 months postoperatively. Histopathologic analysis
was used to validate the ultrasound-based diagnosis.