Introduction

• Cause: diet, neoplasia, chronic renal failure, impaired calcium excretion, vitamin D toxicosis.
• Signs: calciuria, urolithiasis, metastatic calcification of tissues.
• Diagnosis: biochemistry, diagnostic imaging.
• Treatment: reduce calcium intake, fluid therapy, treat underlying cause.
• Prognosis: depends on cause.

Pathogenesis

Etiology

• Hypercalcemia of malignancy is reported in ferrets with lymphoma Lymphoma overview.
• May occur secondary to chronic renal failure Renal failure.
• Excessive vitamin D supplementation may lead to hypercalcemia and metastatic calcification of tissues.
• Primary or secondary hyperparathyroidism.
• Osteolytic bone tumors.
• Laboratory error and sample hemolysis should be ruled out.

Predisposing factors

General

• High calcium diet.
• High vitamin D in diet or excessive supplementation.
• Chronic renal failure.

Pathophysiology

• Hypercalcemia is the result of increased uptake from gastrointestinal system, excessive release from bone, or decreased renal excretion of calcium.
• Parathyroid hormone activates osteoclasts, with release of calcium from bone. PTH also promotes renal conservation of calcium and stimulate the synthesis of active vitamin D by the kidneys.
• Vitamin D and its analogues increase gastrointestinal uptake of calcium. At high levels, calcium is also released from bone.
• Osteolytic processes result in release of calcium and phosphorus from bone.

Timecourse

• Usually chronic.

Diagnosis

Treatment

Prevention

Outcomes