Brucella infections constitute a serious problem for dog breeders, pet owners, and kennels, leading not only to economic costs associated with reproductive loss, but also a public health concern because of the zoonotic potential. The disease, once established, is difficult to control due to the lack of a protective vaccine for canine use. Historically, brucellosis control efforts have demonstrated that the spread of the disease is preventable or significantly reduced in association with vaccination. Unfortunately, efforts to develop a brucellosis vaccine that is safe and effective for dogs have been unsuccessful to date. The goal of this research is to develop a safe and efficacious Brucella canis vaccine using a genetic mutant that has been shown to be safe and efficacious for controlling infection against other Brucella species. The development of a safe and highly protective brucellosis vaccine for dogs will significantly impact canine and human health by limiting the spread of disease.