Serum and blood samples from 86 wolves taken in northern Canada were examined for neutralizing antibodies to canine distemper, infectious canine hepatitis and canine herpesvirus. The tests were performed on eluates prepared from paper discs previously saturated with serum or blood from wolf carcasses. Canine distemper and infectious canine hepatitis antibodies were demonstrated in two and eleven samples respectively. No reactors were detected for canine herpesvirus. These findings indicate the existence of the viruses of both CD and ICH in free-living wolves in northern Canada. However, their significance in these animals is not known.