Intradural vasculitis and hemorrhage in full sibling Welsh springer spaniels.

Two, full sibling, Welsh springer spaniel presented at 8 and 18 mo of age with rapidly progressive ataxia, recumbency, and pyrexia. The spinal cord contained extensive subdural hemorrhage and, in 1 dog, suppurative and necrotizing arteritis in the dura. The findings suggest a familial form of canine juvenile polyarteritis syndrome.