zooprophilactic
adj.— «He’s also interested in birds that are what’s called “zooprophilactic.” They may dilute the spread of disease, he said. Doves, pigeons and herons seem to be dead ends for West Nile, he said. Florida has large numbers of them. “If an animal does not transmit it, it’s actually protecting us,” Komar said.» —“Human cases of West Nile dwindle” by Stacey Singer Palm Beach Post (Florida) July 22, 2006. (source: Double-Tongued Dictionary)