Test description: Serum measurement of 25-hydroxyvitamin D, the primary metabolite used to assess vitamin D status in dogs and cats.
Comments: Recommended for investigating calcium and phosphorus metabolism disorders, nutritional assessment, endocrine diseases, and monitoring vitamin supplementation.

• Sample type: Serum
• Species: Canine, Feline
• Optimal volume: 1.0 mL
• Minimum volume: 0.8 mL
• Container: Tube with a red or yellow cap, without a gel separator
• Fasting: 8 a.m. to 12 p.m.
• Rejection Criteria: Hemolyzed, lipemic, or insufficient sample volume

Shipping
Follow the step-by-step instructions in our Pocket Guide.

• Low levels: Vitamin D deficiency or insufficiency, associated with chronic kidney disease, unbalanced diets, or gastrointestinal disorders.
• Elevated levels: may be related to excessive supplementation or vitamin D toxicity.
• Results should be interpreted in conjunction with calcium, phosphorus, and PTH.

Test Method
Paramagnetic Microparticle Immunoassay (PMI).

Test description: Serum parathyroid hormone (PTH) assay; PTH is a hormone secreted by the parathyroid glands and is a key regulator of calcium and phosphorus metabolism.
Comments: Indicated for the investigation of primary and secondary hyperparathyroidism (nutritional or renal), hypoparathyroidism, and monitoring of chronic kidney disease.

• Sample type: Serum
• Species: Canine, Feline
• Optimal volume: 1.0 mL
• Minimum volume: 0.8 mL
• Container: Tube with a red or yellow cap, without a gel separator
• Fasting: 8 a.m. to 12 p.m.
• Rejection Criteria: Hemolyzed, lipemic, or insufficient sample volume

Shipping
Follow the step-by-step instructions in our Pocket Guide.

• Elevated PTH + low calcium: consistent with secondary hyperparathyroidism (renal or nutritional).
• Elevated PTH + high calcium: consistent with primary hyperparathyroidism.
• Low PTH + low calcium: consistent with hypoparathyroidism.
• Results should always be interpreted in conjunction with total/ionized calcium, phosphorus, and vitamin D.

Test Method
Immunoassay using paramagnetic microparticles (PMI).

Test description: Serum parathyroid hormone-related protein (PTHrP) assay.
Comments: Test used primarily to investigate hypercalcemia of malignant origin, especially in dogs with lymphoma or epithelial tumors.

• Sample type: Plasma
• Species: Canine, Feline
• Optimal volume: 1.0 mL
• Minimum volume: 0.5 mL
• Container: EDTA tube with a purple cap
• Fasting: 8 a.m. to 12 p.m.
• Rejection Criteria: Hemolyzed, lipemic, or insufficient sample volume

Shipping
Follow the step-by-step instructions in our Pocket Guide.

• Elevated levels: strongly suggestive of paraneoplastic hypercalcemia.
• It should always be interpreted in conjunction with total and ionized calcium levels, imaging studies, and the patient’s medical history.

Test Method
Radioimmunoassay (RIA).

Test description: Serum measurement of 1,25-dihydroxyvitamin D (calcitriol), the biologically active form of vitamin D responsible for regulating calcium and phosphorus metabolism.

Comments: Indicated for the investigation of mineral metabolism disorders, hyperparathyroidism, renal failure, granulomatous diseases, and unexplained changes in serum calcium levels.

Unlike 25-OH vitamin D (calcidiol), which reflects the body's stores of the vitamin, calcitriol measures the active and functional form of the hormone.

• Sample type: Serum
• Species: Canine, Feline, Equine
• Recommended volume: 0.7 mL
• Minimum volume: 0.5 mL
• Container: Tube with a red or yellow cap
• Rejection Criteria: Severe hemolysis, marked lipemia, or insufficient volume

• Elevated levels:
  May occur in primary hyperparathyroidism, granulomatous diseases, or calcitriol-producing neoplasms.
  
• Reduced prices:
  Associated with chronic kidney disease or impaired renal activation of vitamin D.

  * The interpretation should always take into account calcium, phosphorus, PTH, and 25-OH vitamin D.

Test Method

Paramagnetic Immunoassay (PMI)