Many elastodynamic solutions exist for wave interactions with defects upon or within an elastic half space bounded above by a vacuum. The aim of this paper is to significantly widen the scope of these solutions by showing that they can be directly utilized, when the vacuum is replaced by a fluid, to find the leading order acoustic (or elastic) responses in the light fluid-loading limit. Using the procedure developed here one can take virtually any elastodynamic solution and use it to generate the leading-order solution for a fluid-loaded elastic solid.