Cause | Reason | Treatment |
---|---|---|
Primary hyperparathyroidism (relatively rare in dogs) | Parathyroid glands are overactive (often due to a tumor) and secrete excessive parathyroid hormone | Removal or destruction of tumor |
Hypercalcemia caused by cancer (malignant hypercalcemia) | Increased bone breakdown and resorption triggered by cancer cells causes higher levels of calcium in blood | Depends on specific type of cancer |
Hypoadrenocorticism (Addison’s disease) | Multiple factors involved; up to 30% of dogs with Addison’s disease have increased calcium levels | Treatment of underlying disease normalizes calcium levels |
Chronic kidney failure | Exact mechanism unknown | Supportive care |
Vitamin toxicity | Vitamin D supplements taken in excess (for example, to treat hypoparathyroidism); accidental ingestion of calcipotriene (a human psoriasis medicine) or of rodent poisons containing calcitriol (no longer widely available in the US) | Adjustment of vitamin D dosage (if from medication); calcipotriene poisonings are often fatal |
Granulomatous disease (masses of white blood cells that can form because of certain fungal and parasitic infections) | Inflammation activates the type of white blood cells that can increase levels of vitamin D | Treatment of underlying disease, for example, antifungal drugs or surgery |
Houseplants (Cestrum diurnum [the day-blooming jessa-mine], Solanum malacoxylon, Triestum flavescens) | Contain substance similar to vitamin D that may cause hypercalcemia when accidentally eaten | Supportive care; corticosteroids |
Bone tumors (rare) | Breakdown of bone increases blood calcium levels | Depends on specific type of cancer |