Hi Mothra, I too rescued a Dend from Lowe's not so long ago and it resembles yours but is a lot smaller, being a phal girl myself I haven't come to understant dends too well, mine so far is developing new roots and 2 canes, so I must be doing something right, jejejeje, this is what I did:
I repotted mine in a fine/med fir bark mix, I water weekly, fert weakly twice a month (MSU fert) and have it sitting in a north facing window that catches most of the morning sun.
As for yours, it looks ok to me... I've seen canes with those same furrows and no leaves on a Dend my mother in law has and lately it seems to be growing new leaves so I wouldn't worry much.
Hope to be of some help
, and hopefully our pals on the Dend alliance can give further expert advice
Priz