  We show how to resum neutral propagators to all orders in Partially Quenched
Chiral Perturbation Theory. We calculate the relevant quantities to
next-to-next-to-leading order (NNLO). Using these results we show how to extend
the proposal by Sharpe and Shoresh for determining the parameters relevant for
the eta mass from partially quenched lattice QCD calculations to NNLO.
