https://www.merckvetmanual.com/all-o...-Rats_v3230138

Kidney and Urinary Disorders of Rats

Chronic progressive nephrosis (glomerulonephrosis) is a common disease of older rats. It involves inflammation of the blood vessels in the kidney. The disease and its severity are influenced by the rat’s sex and hereditary background and by dietary factors such as protein content and total calorie consumption. The disease occurs earlier and is more severe in male rats than in female rats. Affected rats are lethargic and lose weight, and they may have increased thirst and urination
Even with, "Late Stage" Kidney failure in rats, kidney function was improved with oral Calcium citrate. Although other calcium supplement forms were also tested, including Calcium carbonate; they were not found to improve kidney function.

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Diabetes caused by both excessive protein (phosphorus), fat (lipids), and sugar (triglycerides), resulting in insulin resistance, which promote kidney disease, which results in high blood pressure. In research study of these same disorders in rats, oral supplementation of Quercetin. Quercetin can also improve high blood pressure with this same condition. High blood pressure is associated with heart attack, stroke.

In conclusion, our results indicate that quercetin reverses the increase in blood pressure, providing an improved clinical condition in an animal model. This was evidenced by the improvements in the lipid profile and increase in insulin sensitivity through the activation of the initial steps of the insulin signaling cascade in adipose tissue, followed by a protective mechanism against the action and secretion of pancreatic islets., in rats.
Kidney infection can be due to the regular consumption of foods higher in oxalic acid, and or being too acidic from an unhealthy imbalance in the (Ca:P) ratio of the total diet, not just the block diet alone. With commercial rodent block diets being closer than (2:1) (Ca:P) the recipe for disaster is set up when a whole foods component is added to the diet that is lower than equal to that of the block diet itself. Figuratively speaking, this like skating on thin ice and finding that the ice has gotten so thin that it eventually gives way.