Sounds like the cows win this round of cows vs. roses.
Rose rosette disease is something I have heard about but not encountered, fortunately. Most of the rose gardeners who seem to know anything about it hale from California. Many people elsewhere do not. Am I right in assuming it is spread by insects? What other factors favor its transmission? Are all roses with multiflora heritage more susceptible to it than others? Are there roses that - like typhoid Mary - harbor the disease but do not show symptoms of it? When I purchase plants at a big box store, how do I check for it: is it even possible if the plant is not leafed out?