Exactly what my vet said, but then hedged it with "well, she's gonna die anyway, so if you want to try it, it's your cat". (sorry, I'm not paying for, or subject a cat to Dialysis and whatever. When it's time to die, it's time to die and there are always more cats, dogs, guinea pigs.... whatever that are ready for a good home as well.) Granted though, she was a hunter, so I guess she got her calcium from eating the critters she caught. She'd get a can of Bumblebee a day, half in the AM and half in the PM. She lasted another 3 years on that diet. Had a cat that was insulin dependent diabetic until switching him to the same diet. 6 weeks later, no more insulin and the weight was coming off. Commercial cat food is garbage.