In which condition is hypercalcemia commonly seen?

Hypercalcemia is commonly associated with paraneoplastic syndromes, which are a set of symptoms caused by cancer's impact on the body, often independent of a direct tumor effect. In particular, some tumors secrete parathyroid hormone-related peptide (PTHrP), leading to increased calcium levels in the bloodstream. This situation occurs because PTHrP mimics the action of parathyroid hormone (PTH), regulating calcium and bone metabolism, thus driving the release of calcium from bones into circulation.

In paraneoplastic syndromes, the hypercalcemia can be a significant clinical finding, and recognizing it can often help in diagnosing an underlying malignancy. Understanding the link between certain tumors and hypercalcemia is crucial for proper treatment and management of affected animals.

The other conditions listed may have varying relationships with calcium levels, but they do not have the same direct and prevalent association with hypercalcemia as seen in paraneoplastic syndromes. For instance, osteoarthritis primarily involves joint degeneration, while chronic kidney disease is more often associated with hypocalcemia than hypercalcemia due to imbalances in calcium and phosphate metabolism. Primary hyperparathyroidism does lead to hypercalcemia, but it is not as commonly discussed in the context