Hi Pattie,
Although the 'traditional' view is that low protein diets are the way to go for cats with kidney disease, many people's
experience is that their kitties do much better on a diet that isn't protein-restricted (particularly in the early stages of kidney disease). I think the low protein model may have been devised for dogs, and then cats were just treated the same way (someone please correct me if I'm wrong).
I also took in a foster kitty who was then found to have kidney disease. (In our case the charity I foster for wanted to have him PTS, so we decided to formally adopt him so we could try to extend his life if possible).
One of the problems with low protein diets is that kitties can lose weight and muscle mass (especially if they don't like the food!). And that means they're less able to cope with any kind of illness. And of course, low protein diets tend to be high carb. And if a diabetic kitty's blood glucose goes up that can put even more strain on the kidneys...
Our CRF kitty was 'skin and bone' when we first took him in. But after a short while on a decent diet he put on a really nice amount of weight. That never would have happened if we'd fed him a low protein diet.
His blood phosphorous level was borderline high so I put 'phosphorous binder' in his food to help reduce phosphorous absorption.
I would have considered lower protein diet in the later stages of the disease, but unfortunately (and completely unexpectedly) he deteriorated over a matter of hours one day and had to be PTS. It was discovered - too late - that he had very high blood pressure, and that caused his death quite suddenly.
I wish I had know then what I know now about the dangers of high blood pressure in CRF kitties, and if one of my other kitties ever develops CRF in the future I will be forewarned and be able to take action sooner.
If at all possible I would strongly suggest that you get your foster kitty's blood pressure checked, as high blood pressure
is treatable with medication.
Do have a look at the CRF site that BJ linked to in her post above. It is a fantastic resource. The info there is also available in (huge!) book form, and I've found the book to be even more useful than the website because I can mark the pages and make notes in it.
The CRF support forum is another great resource. People there are very kind and knowledgable. They helped me when I was completely lost, scared and clueless; and were endlessly patient in explaining things.
Your foster kitty is very lucky to have you care for him. Bless you, and good luck.
Eliz
