My maltese bow, had an apse in her mouth and we got that taken care of by antibiotics.Although she is still drinking an excessive amount of water every day. She wakes up in the middle of the night and drinks all the time. I do not know if the spot where her apse was still affects her or that she has another issue. Any suggestions?
probably another issue. so many possibilities. she really ought to go to her vet for some bloodwork, at her age they can do very comprehensive bloodwork such as a "senior panel" that will show such things as complete blood count, liver function, kidney function. this will give them a very good indication of her health status and help get to the bottom of the drinking quickly.
If the medication is a steroid, it can cause excessive drinking. I would have agree with poodlerus, a senior blood panel is not a bad idea. I just had it done on my 9yr old poodle. They are always a good idea.