Our faithful 11yo Australian Shepard was recently diagnosed with hypercalcemia. He started having some urinary incontinence issues last fall. We had bloodwork and urinalysis (normal) done back in November that showed his blood calcium level to be high (13.5mg/dL). We were prescribed Proin for the urinary issues and went about our lives. It appeared that the Proin provided a bit of improvement with the incontinence.

Unfortunately, since then, the incontinence has gotten worse (still not horrible, just dribbling basically). We took him back in for another round of bloodwork/urinalysis here a couple of weeks ago. Urinalysis was normal but calcium level in blood was still high (14.5mg/dL). We proceeded to have further bloodwork done to test parathyroid level which came back normal. Given the normal parathyroid results, we were informed that most likely cause of the hypercalcemia was malignancy.

Yesterday he went in for abdominal ultrasound as well as Nu. Q blood cancer test. Thankfully, both tests were negative for cancer. At this point, our vet isn't really sure what is causing the hypercalcemia. Only advice was to try to make some dietary changes. Do any of our resident DVMs have any insight into something like this? I'm sure the hypercalcemia is contributing to the increased thirst/urination/urinary incontinence issues. The elevated calcium levels will also lead to kidney damage as well. Aside from this issue he is in great shape for an 11yo dog. Would love to get a few more good years out of him. Thanks for any advice you may have.

Also check for whip worms

Thanks for the replies. Suggestions like this are what I was hoping for.

Would there be any value in replacing his drinking water with distilled water while we try to figure this out? He currently drinks the same carbon filtered water as us from the fridge spout. I know our calcium hardness is on the high side. Might be a silly idea but I though it might be worth a shot.

If calcium is high, parathyroid hormone (PTH) should respond by going lower, not staying normal. Its a feedback loop, in this case it would be abnormal for PTH to be normal if that makes sense.

Parathyroid ultrasound may be warranted to look for an enlarged parathyroid (usually need specialist for this). Would also check for heterobilharzia.

First reply was anal sac tumors, also needs checking.

Hypercalcemia is one of the markers for Heterobilharzia Americana.

https://vetmed.tamu.edu/gilab/service/assays/heterobilharzia-americana/

Can get more info of the program being run by A&M and a test kit here:

https://thedrakeproject.my.canva.site/

I very much appreciate your replies.

Definitely sounds like there's a few easy follow ups we could do. I don't think he's had a rectal exam to check for an anal gland issue so will request that.

His intact PTH was 1.4 (scale 1.1-10.6) so I was wrong in saying it was normal. I suppose that may signal that PTH is functioning normally in response to the high Ca?

For the parasites, I assume those would be found in a stool analysis? I can also request that going forward.

Thanks again guys. Really appreciate your insight.

When we see high Calcium we go on a cancer hunt. But it could also be metabolic. High calcium is hard on kidney cells.

Should we switch him to a special kidney diet food?

Kidney diets are generally low in protein to decrease the load of urea the kidneys have to handle (urea a byproduct of protein metabolism). They may be of some benefit but will not lower Calcium levels.

Your primary differentials for hypercalcemia are cancer and Hyperparathyroidism. Bloodwork will rule in or rule out Hyperparathyroidism.