There are several strains of the virus that are carried by different species of animals. A “strain” of rabies is a form of the virus that is primarily carried by a specific species of animal, known as the dominant reservoir species. Although a strain is specific to a particular species, other mammals are susceptible to that strain as well. When an animal other than the normal host species contracts the virus, it is called a spillover. In the case of the raccoon strain, which has been affecting the New England area since September of 1992, the most common spillover animals have included skunks, cats, woodchucks, and foxes. The fact that spillover occurs is cause for some concern.