Have your doc test the PTH -- parathyroid hormone levels too. The parathyroids sit on the thyroids and do quite a bit of the calcium balancing job. I don't know about dogs but in humans parathyroid disease is almost always the cause of high calcium.
Sometimes tumors can grow on the thyroid gland that can affect both the thyroid production and the parathyroid processes. Most often these tumors or nodules are benign. Removing them can often fix the problems -- but many times the whole thyroid gland and maybe some of the parathyroids have to be removed. In that case, the patient has to take hormones by pill the rest of their life.
I have quite a bit of experience with thyroid and parathyroid problems as they relate to people. At least it gives you someplace to start a conversation with your vet. |