Recently, an opportunity to help out with a sick cactus presented itself so I thought I would document the process and create a thread.
The cactus is suffering a little but still has much life to give.
Over the next few days we are going to want to change a few things in regards to the environment.
First off, we'll devise a new soil mix to replace the peat-based soil in which she is currently potted. Peat based soils can become acidic over time and lophophora thrive in a more basic (higher pH) environment.
Second, we'll make sure to re-pot her into a more porous clay pot. The glazed pot in which she currently resides would be better suited for geraniums - but not cacti.
Being away from a certain dog (who saw fit to periodically "water" this specimen) will do wonders in and of itself. A re-potting and revision of growth medium will help sort out any pH issues caused by soil composition and pet additives.
This cactus is just coming out of winter so we should be able to see some results fairly quickly as she recovers in the new digs.