Question

My dog, Lace, an American Pit Bulldog, is 13. The first of last year, I noticed she was developing a pot belly and seemed to be drinking a lot of water, which in turn produced a lot of urine. Took her to the vet who of course dewormed her. He checked her for diabetes - negative. He then said that she may have some heart failure and some kidney problems developing. She had been treated about ten years ago for heartworms and he said that there is of course no way to know how much damage was done. After the deworming however, she seemed to look a little better and her belly was not quite as distended. She didn't seem to be needing as much water either. I thought that maybe because we found her to be so infected with tapeworms, that the deworming had done the trick. But then her belly got big again, her thirst returned and I noticed tapes again on her stool. I have treated her for this again. The belly is still big, her thirst is endless. Sometimes drinking half a gallon at a time. I think even her appetite has actually increased. She does not seem to have lost weight. Her coat is not as shiny as it once was, but she is not shedding. Her front teeth are worn to the gums and she has lost a few of her jaw teeth. She does have cateracts. I know that she is getting older and want her to be comfortable, but she seems miserable. Any ideas as to what may be causing these symptoms?