The department says samples from the animal have been sent to a Canadian Food Inspection Agency lab in Ottawa for confirmation of the diagnosis.
It's the first case of rabies reported in Labrador since July 2014.
The wolf was killed by conservation officers on Jan. 25 after it exhibited aggressive behaviour towards snowmobilers.
The department says there was no word of any human or domestic animal contact in the incident.
People who live in the area are encouraged to take precautions when encountering animals acting in a strange or aggressive manner.