High Blood Calcium & Back Pain

Many Possible Causes but Cancer Tops the List


Our 12 year old Lab/Border Collie has had back pain for 2 years and is very weak in the back legs. We’ve done a variety of treatments and none has worked. His appetite is seriously declining. All blood tests were normal except for high calcium. Our vet says that indicates cancer of the parathyroid. Surgery and chemotherapy are not options for us. We understand that his condition will lead to renal failure. How can we improve the calcium level?


Dr. Nichol:

Your dog’s pain and hypercalcemia (CQ) (elevated blood calcium) are worrisome. Controlling his calcium is important but only treatment based on a clear diagnosis can save his life. He needs help soon.


There are several possible causes for hypercalcemia but topping the list is lymphosarcoma (malignancy of the lymph system). Other considerations include anal gland tumors, multiple myeloma (CQ) (a cancer that can involve bone), and toxic amounts of vitamin D (usually from rodent poisons). Other possibilities are kidney failure, fungal infection, low functioning adrenal glands, and primary hyperparathyroidism (tumors of the parathyroid glands).


This may sound like a dizzying array of medical disasters but making a diagnosis is usually fairly straightforward. Beyond a routine lab profile, x-rays of your dog’s back, abdomen, and chest are important to evaluate his lymph nodes and bones. Ultrasound is another diagnostic tool. If the cancer lesions of multiple myeloma are found your dog’s back pain and hypercalcemia will both be understood.


This boy’s quality of life is worth the investment to find the real cause of his pain. If he has parathyroid gland tumors they are treatable by a new non-surgical method called ultrasound guided heat ablation. Still, there is no way to help him until we know what’s wrong.