Bovine viral diarrhea virus and Leptospira spp. are two of the common pathogenic organisms responsible for reproductive losses in cattle worldwide. Both can be come endemic in herds resulting in chronic low-grade reproductive losses or they can be introduced into relatively naïve herds, resulting in substantial reproductive losses over a short period of time. Both organisms are a differential diagnoses for common reproductive losses that veterinarians investigate, including low conception rates and abortions.