The bird infecting viral strain H5N1, commonly known as the Avian Flu, is a highly infectious and resilient virus that can be fatal if contracted by humans. Authorities and health services have a major responsibility to citizens to respond quickly to minimize the possibility of a localized outbreak becoming a pandemic. The Avian Flu Tracker is a dynamic Location Based Service (LBS) designed to warn citizens of their proximity to potentially infectious regions. The system tracks the location of infected zones, dynamically estimating the spread of an uncontained area over time. Users subscribed to the service receive SMS messages alerting them of the potential for danger based on their current location, and a recommended course of action. By utilizing a scalable and distributed architecture, predictive modeling and innovative zone technology to assign threat levels to spatial data, Avian Flu Tracker demonstrates that LBS can aid to stem and control the spread of the pandemic.