A ex-NYPD transit cop was arrested in the Long Island slaying of his wife after State Police ­using bloodhounds tracked him down in woods upstate.

Paul Leitgeb, 49, was found late Tuesday afternoon near the Appalachian Trail in the Dutchess County town of Pawling, said Suffolk County police detectives.

Leitgeb, suspected of slaying his wife, Tricia Odierna, 42, in their Lake Grove home last week, held State Police at bay for hours Tuesday, wielding a boxcutter and threatening to harm himself, officials said.

He was taken into custody, briefly hospitalized with wrist cuts, then turned over to Suffolk County police, who brought him back to Long Island where he was charged with second-degree murder.