aww I am sorry to hear this..
yes, you should try what helps humans
1. dr richard schulze's incurables program....use clark's rule
http://www.curezone.com/schulze/handbook/default.asp
for a cat dose, use the cat's weight..the dose for an adult is for a 150 pound person. the average herbal tincture (liquid with eye dropper top) dose is 60 drops 5 times a day. so if your cat weighed 10 pounds you would divide 150 by 10 (150 / 10 =15) so it would be 1/15the regular dose (60 / 15 =4 so 4 drops)..if it was 15 pounds, it would be (150 / 15 = 10) so 1/10th the dose so (60 / 10 = 6 drops and so forth)
http://www.curezone.com/schulze/handbook/CAD.asp here is clark's rule
2. also use wheat grass juice...this is sold at health food stores or as a grass called pet grass in health food stores..do not give too much like maybe an ounce would be a human dose as it can detox too fast if you gave a cup or something. If you can't find it, try barley grass powder from health food store or wheat grass powder but fresh is best...maybe the cat can chew it..you need a wheat grass juicer as it will break a blender but if you have the grass, cut into 1/2 pieces and blend with water and some of it should go into the water (so give more in this case)
3. Also use the hoxsey formula..cat dose
4. also use essaic tea.
all of these things have reversed cancer in people.
5. also raw fruits and veggies and their juices and green tea contain enzymes that break sown the protein coating that surrounds each cancer cell so the immune system can then kill he cancer. Since cat are not vegetarians, I wonder if the enzymes in raw meat would have the same effect. Use freerange meat as this is safer. blend and add some veggie juice (fresh juiced not canned) like carrots and kale and beets and blend with the raw meat or grind it all up and give it to the cat.
http://www.curezone.com/schulze/handbook/default.asp here is the incurables program...if you can't find the hoxsey formula you can use Schultze detox formula..
6 check this thoroughly as well --this website should be of help to search...it deals with sick pets
http://www.shirleys-wellness-cafe.com/
http://search.freefind.com/servlet/freefind?id=9609505&pageid=r&mode=ALL&query=kidneys
http://www.shirleys-wellness-cafe.com/urine_untoldstory.htm
7. urine therapy is said to be extremely helpful for these problems.
8.cordyceps mushrooms have been said to greatly help kidney disease...open the caps and figure out a cat dose and add to the food
9.also give the cat blood cleansing herbs ..get a burdock tincture..again use a pet dose ..the human dose is usually 60 drops 5 times a day for tinctures. This is to help with the poisons from nonfunctional kidneys. Parsley root is a good one..it is sold in the produce department of some meijers and looks like a carrot with a parsley looking top like a carrot but white..juice it and add to food or make a tincture and give by drops (kidneys)
hope this helps...it is unlikely you could do this with the cat at the vets.