His PTH parathyroid test is the same as last year's test-zero-where it shouldn't be. That's a bit of an anomaly. Usually, if calc is high, PTH is high, indicating an issue with the parathyroid. We now need to do a throat scan of the parathyroid to rule out issues with it before proceeding to think of the calcium level as idiopathic. And if we can get him to be calm there or at his vet, retest his urine. And if idiopathic hypercalc, find a solution to bring down the calc, and up the phos. Still waiting on MSU to call me back to schedule the scan. Will let you know more in a week or two after we've had the scan.
As a reminder, hypercalcemia is not normal in a cat or even in a human. It can be brought on by poison, too much vitamin D, cancer or other disease such as kidney disease (it can be the result of kidney disease or it can cause kidney disease), Feline Leukemia or Feline Immune disease, and issues with the parathyroid. It means the body isn't absorbing into the bone the calcium and the excess is "spilling" into the body, ready to play havoc. If the phosphorous is high, will combine with calcium to create cement in the heart and kidneys. But hypercalc itself brings on many other problematic symptoms such as lethargy, vomiting, lack of eating, etc. And lack of eating, lack of drinking just brings on even more problems. Hypercalcemia can endanger the cat's life.
For more information here are some links and they are just three of hundreds or more online:
http://felineihc.org/ For more on idipathic hypcalcemia