I would ask the vet about giving her fluids at home. Giving the fluids take less than a half an hour a day so you need not worry about restricing her movements for long. You should also ask your vet for an antiemetic (anti-nausea) medicine, such as Reglan or Cerenia which may get her eating again. These are oral medications and can be given at home. Get her eating anything if possible. Try a variety of different meats, fish, or dairy products. The meat can be very lightly cooked, or rare to try to stimulate her appetite. Try feeding her some kidney.
My dogs crea was 21.2 last Sunday and yesterday it was down to 15. I brought her home for the evening and tried to give her some boiled chicken but she wouldn't eat anything other than a small milkbone and no water. This morning she had about 2 cups of water and another milkbone with some Pepcid AC, Doxycycline, and medicine for diarhea. I took her back to the vet this morning for more fluids. She is good spirits at home and very active, almost normal. When I bring her to the vet she starts to shake knowing that she is going to be stuck in a cage all day amongst strangers. I plan on picking her up again this evening at 6:30pm. Hopefully she will eat something. I also plan on taking off the next 2 days which will give me 4 days with the weekend to spend with her. Should I ask the vet for Saline bags and give her fluids at home? I would have no problem restricting her movements, but I think she would be more responsive If I was present.
It is possible that the Lyme disease could have infected her kidneys. This disease is called Lyme Nephropathy and can cause severe kidney damage.
I would have your vet make sure that the elevated kidney enzymes are not caused by pyelonephitis (infection and inflammation of the kidneys) or a urinary tract infection with uroltihs (bladder stones) which can be treated and can cause acute kidney failure. A urine culture and sensitivity would not hurt either. I would also have another Lyme test and make sure she doesn't have to be treated again for Lyme disease. These are treatable diseases that can contribute to kidney disease. If she does not have pyelonephritis, UTI, or Lyme than she truly does have chronic renal failure.
Unfortunately, there is very little in traditional veterinary medicine that can treat damaged kidneys. There is more hope for failing kidneys with alternative medicine. If she truly does have chronic renal failure there are things that can be done to increase her chances such as giving sub-Q fluids at home, using epatikin to lower a high phosphorus level, feeding her a special prescription diet such as Hills K/D. On the alternative medicine there is a Traditional Chinese Medicine herb called: Rehmannia 8 that is helpful for renal disease. A holistic vet may be able to help you further. Please check the American Holistic Veterinary Medical website (AHVMA) for a holistic vet near you.