My 14 year old daschund/heeler mix went blind over a year ago. Around the same time, she was diagnosed with liver cancer that "should not affect her length of life". We have done many things to help her adapt and overall she does well as long as we are with her. When we aren't home she paces and howls almost the entire time (I've video taped her). Yesterday, my husband saw her licking urine that she had excreted on our floor. I am at my wits end and would like to try Prozac, but two vets have turned us down. I don't think this is purely a behavioral issue-my husband and I both have Ph.D.'s in behavioral psychology and have solved many of her behavioral issues in the past. I've also followed recommendations regarding separation anxiety such as not making a big deal about leaving and coming back. I've also tried leaving her toys like Kongs to keep her occupied, but once she gets the food, she reverts to howling and pacing. Is there anything we can do to help her?

Optional Information:
Age: >12; Female; Breed: daschund/heeler

Already Tried:
walks before we leave
giving her tongs and similar toys to keep her busy
experimented with how much of the house to block off-we block off about half
leave her several comfortable places to lay
use different scents in different parts of house so she knows where she is
leave our worn clothes for her to lay on
leave music playing