Hogs carry deadly diseases, such as swine brucellosis, pseudo-rabies, trichinosis, and leptospirosis. Some scientists estimate that feral hogs are capable of carrying in excess of 30 different diseases, putting domestic livestock that live close to these invaders at severe risk. One of the most deadly hog-carried diseases is pseudo-rabies, which is related to the herpes virus. Though it does not infect people, pseudo-rabies weakens domestic pigs' immune systems and can cause stillbirths. This disease can be carried to various domesticated animals and there is no known cure.