research on High-protein, non-renal food for CRF

Does anyone have any citations or actual studies that I can show to my vet showing how the renal food is not nec. ideal. Since I now have to go back to my vet to discuss Fred's new issues posted earlier today, I am gonig to ahve to deal with his disapproval that I have refused to get him off his low carb diet. So I would like to go prepared with research because when I mentioned that renal food (and low protein for kidney humans, too) was old thinking he totally disagreed with me. This is a vet who doesn't prescribe hometesting, rec. DM and I have not been overly impressed with his Db know-how, so not entirely willing to take his word on the kidney stuff.

 

To my knowledge there isnt one because the pet food companies fund all the studies and they want people to buy the RX diets. The problem is that all the studies-the few there are (to my knowledge) used food that was BOTH low in phosphorus, AND low protein . So there is no way to prove that it was the low phos and not the low protein.

From http://www.catinfo.org Dr. Lisas site
"Please also note the following list of the first four ingredients of Hill's Prescription dry k/d after reviewing this section on reading a pet food label - and bearing in mind that your cat is a carnivore. This is a diet that would never find its way into a food bowl owned by any cat in my care. The first three ingredients are not even a source of meat and the fourth ingredient is a by-product meal which is not necessarily an unhealthy source of protein but it would be nice to see some muscle meat ("chicken") in this product.

Brewers rice, corn gluten meal, pork fat (preserved with mixed tocopherols and citric acid), chicken by-product meal

The purpose of this prescription diet is to restrict protein which, unfortunately, it certainly does. However, please understand that there are no studies showing that restricting protein to this level will prevent further deterioration of kidney function.

k/d restricts protein to the point that some cats - those that are not consuming enough of the diet to provide for their protein calorie needs - will catabolize (use for fuel) their own muscle mass which results in muscle wasting and weight loss. This internal breakdown of the cat’s own muscle mass will cause an increase in creatinine which needs to be cleared by the kidneys. The rise in creatinine, and muscle wasting, can lead to an often-erroneous conclusion that the patient’s CKD is worsening.

Of course, the same deterioration can occur in any cat that is not consuming enough protein, but the level of protein in this diet is not only at an extremely low level, it is in an incomplete form for a carnivore. Note that it is made up mainly of plant proteins - not meat proteins. It is also water-depleted as is the very definition of all dry foods. "

http://www.holisticat.com/crf/Diet-what ... ssues.html
http://mousabilities.com/nutrition/crf/ ... ein_RD.pdf
pdf link from Feline outreach
http://www.felineoutreach.org/Education/Kidney.html
http://www.littlebigcat.com/index.php?a ... w&item=003
http://www.felinecrf.org/nutritional_requirements.htm

 

All the research I know of shows that renal diets prolong lifespan, so I doubt there is any convincing of the vet. As Lisa said, the diets are usually lower protein (not always low), low phos, low sodium, and supplemented with potassium, so it is likely that a combination of some of these (though perhaps not all of these things together) does help.

 

Martica I don't know if you've seen all this info from the old board.

May be of some help?

http://www.felinediabetes.com/phorum5/r ... ?8,1783285

 

The other issue that I rarely see my colleagues address is WHEN to consider protein restriction - which most CKD-savvy vets consider to be when the BUN is rising substantially. (Say.....over 50ish...give or take.)

BUN is a waste product of protein metabolism but is not considered to be a renal toxin. ie...it is not considered to actually cause further harm to the kidney but...who knows....maybe it does and we just don't recognize it??

What we do know is that elevated BUN can make the cat feel lousy. Therefore, if BUN is a waste product...and the kidney is not 'dumping the body's trash can' very well...it makes more sense to not give them so much trash.

Only at that time will I consider lowering the protein a bit. I prefer to do this with a CKD homemade diet that is very low in phos but many people don't want to make cat food. (These recipes are not on my site since I consider diet to be an Rx situation for each patient.)

 

Thank you so much. Some of this I can bring in--and can def. print out Dr Lisa's take on it. He def. was very sure of himself that the research definitely proved that the renal diet slowed the progression of CRF and made them live longer.