Hi dan g,
I don’t know what you googled, but here are a variety of links that are backed by research studies.
Here’s a link that’s fairly easy to read. This was a study that was in a Purina nutrition forum that found that even dogs with renal failure actually had a higher mortality rate on the low protein diet:
http://www.dogaware.com/files/bovee.pdf
A lot of people like Purina’s research:
https://www.purinaveterinarydiets.com/media/1132/senior-pet-food-protein-facts.pdf
Eating dehydrated food their whole life, leaving them in a constant state of slight dehydration and dental disease are more likely causes of kidney failure.
http://www.dogsnaturallymagazine.com/kibble-never-a-good-option/
http://www.avdc.org/periodontaldisease.html
http://veterinaryteam.dvm360.com/how-periodontal-disease-can-affect-pets-organs?rel=canonical
http://www.iris-kidney.com/education/risk_factors.aspx
