Sera from 210 pronghorns (Antilocapra americana) ranging in southeastern Alberta were tested for antibodies to disease agents present in indigenous cattle. No antibodies to Brucella abortus, Leptospira interrogans serovars pomona, hardjo, or grippotyphosa, or infectious bovine rhinotracheitis virus were found. Antibodies at prevalences of 43.8% and 49.2% were detected to bovine virus diarrhea (BVD) and parainfluenza type 3 (PI-3) viruses, respectively. The much higher prevalence of BVD virus antibodies in cattle than in pronghorns, and the occurrence of clinical bovine PI-3 infection in the study area, suggest that cattle may be a source of infection to the pronghorns.