I'm so sorry to hear about Daisy. Liver shunts are pretty serious, as I'm sure you know. Is surgery an option for her? Is she on a low-protein diet?
As for the Denamarin, you could either order it online (shipping brings it up to around $45/bottle), or instead give her the milk thistle (silymarin) and Denosyl (SAMe) separately. Some links for you:
http://www.nutramaxlabs.com/products...iver/liver.asp
http://www.veterinarypartner.com/Con...=31&A=1319&S=0
http://www.VeterinaryPartner.com/Con...S=0&C=0&A=1779
Give her lots of love and let us know how she does.