[growler~GateKeeper]

Creatinine is a waste product formed by the breakdown of creatine, important for converting food into energy (metabolism). The creatinine is filtered out of the blood by the kidneys and then passed out of the body in urine.

Creatinine is produced at a steady rate and is affected very little by diet or normal physical activities. If the kidneys are damaged and cannot function normally, the amount of creatinine in the urine decreases while the amount of creatinine in the blood increases.

This is what is happening here there is far higher levels of creatinine in the blood than there should be. Especially since the BUN level is not increasing to the same extent - Blood Urea Nitrogen (a byproduct of the breakdown of protein) is affected by stress, dehydration, food, exercise, water levels, creatinine is not to any significant extent.

Creatinine is a natural by-product of muscles doing work in your body. It starts out as creatine phosphate, and it ends up as a waste product in your blood which is then eliminated in urine. This waste product can be easily measured in both blood and urine, and, because it is released at a steady rate by your skeletal muscles, it is an excellent indicator of kidney function. Unlike urea, which also measures kidney function to some extent, creatinine is only slightly affected by the meat proteins you eat. As a result, it is a more precise, more specific measure of your kidney function than urea is.

Creatinine is another waste product excreted through the kidneys. It is generally considered to be a more accurate measurement of underlying kidney function than BUN or urea because it is less affected by diet, stress and dehydration. In CRF cats, both BUN or urea and creatinine will be elevated to some degree depending upon the severity of the disease; but if BUN or urea levels are high yet creatinine is only a little elevated, it usually means that the cat is dehydrated, has gastro-intestinal bleeding, or is eating a high protein diet.

Because creatinine is a by-product of muscle, large, muscular male cats may naturally have high normal levels of creatinine.

Creatinine is the end product of phosphocreatine metabolism, which is important in muscle contractions. High levels indicate kidney failure or disease, dehydration, shock, certain toxin ingestions, poor circulation to the kidneys and urinary obstruction. Low levels indicate liver disease or starvation.

What it doesn't say is what is the reason for: BUN is slightly elevated, phosphorus, calcuim & potassium are normal, Urine specific gravity is good, no urine crystals and the creatinine is very high in comparision to BUN Obviously it is toxic ingestion caused CRF but is there a specific cause for the creatinine to jump like that within the last 5 months?

Waiting for a response to my inquiry about getting the toxicology report from RC. I don't know if it will lead to any help but