My first thought was diabetes. Also, you said she has had several UTIs. Has she been on steroids for this? If so, the steroids could cause her to drink and pee a lot.
Proud Mom to all rescues:
My sweet doggies (S/F) - Laci (dachshund mix), Miss Billie (chihuahua mix) & Tessa (mini dachshund)
My temperamental kitty (S/F) - Short Stuff (short hair calico)
RIP My Precious Kitty - Misty Margaret (long-hair calico) - 08/24/94-03/12/10
RIP Sweet Baby Girl - Lodi Sue (dachshund mix) -01/20/98-11/04/09
RIP My Itty Bitty - Trinket Joy (chihuahua mix) Puppy Mill Survivor rescued 10/00 died 01/22/02
Rescues will touch your heart & soul like no other!