Small animal endocrinopathies 5 Flashcards
Calcium disorders
What are the 2 main differentials for hypercalcaemia in a cat?
- Hypercalcaemia of malignancy
- Idiopathic hypercalcaemia
What is the most common neoplastic cause of hypercalcaemia in cats?
Lymphosarcoma
What group of cats is most at risk of idiopathic hypercalcaemia?
Young to middle aged
How is idiopathic hypercalcaemia diagnosed?
Diagnosis by exclusion, need to rule out everything else
Explain why diagnosis of idiopathic hypercalcaemia can be difficult
- Hypercalcaemia can lead to renal damage (calcium oxalate urolithiasis)
- Can give the impression that the hypercalcaemia is due to chronic kidney disease
When diagnosing the cause of hypercalcaemia, what are the key factors that need to be considered?
- Calcium and phosphate balance: do different things in different diseases
- Hormone balance: also varies depending on disease
What conditions would you be suspicious of in a patient with Severely elevated calcium and moderately low phosphorous?
Primary hyperparathyroidism and hypercalcaemia of malignancy
What conditions would you be suspicious of in a patient with moderately increased calcium and severely increased phosphorous?
Renal failure
What conditions would you be suspicious of in a patient with moderate elevations in calcium and phosphorous?
Vitamin D toxicity and Addison’s
What conditions would you be suspicious of in patient with normal to mildly reduced calcium and moderately elevated phosphorous?
Nutritional secondary hyperparathyroidism
What condition would you be suspicious of with the following hormonal profile: Severely elevated PTH Mild-severely reduced PTHrP Severely elevated ionised calcium Severely elevated vit D
Primary hyperparathyroidism
What condition would you be suspicious of with the following hormonal profile: Mild-severely reduced PTH Severe increase in PTHrP Severely elevated ionised calcium Mild - severely decreased vit D
Lymphosarcoma
What condition would you be suspicious of with the following hormonal profile: Severely elevated PTH Severely elevated PTHrP Severely reduced ionised calcium Mild-severely reduced vit D
Chronic renal falure
What condition would you be suspicious of with the following hormonal profile: Mild-severely reduced PTH Mild-severely elevated PTHrP Mild-severely elevated ionised calcium Mild-severely reduced vit D
Apocrine gland tumours of the anal sac
What condition would you be suspicious of with the following hormonal profile: Mild-severely reduced PTH Mild-severely reduced PTHrP Mild-severely elevated ionised calcium Mild-severely elevated vit D
Hypervitaminosis D
What condition would you be suspicious of with the following hormonal profile:
Mild-severely reduced PTH
Mild-severely reduced ionised calcium
Mild-severely reduced vit D
Hypoparathyroidism
Outline the general management of hypercalcaemia
- May require supportive care until can identify cause
- Active treatment ifc calcium >4.0mmol/L (16.0 mg/dL)
- Treatment depends on magnitude of hypercalcaemia, clinical condition of patient, additional factors e.g. most likely differential and cost, presence of complicating factors e.g. azotaemia, abnormal phosphate levels
List the treatment options for hypercalcaemia
- IV fluids (0.9% saline)
- Diuretics
- Glucocorticoids
- Mithromycin
- Bisphosphonates (pamidronate or zoledronate)
- Most manageed with fluids, diuretics and steroids
Why is the use of fluids or diuretics beneficial in the treatment of hypercalcaemia?
Encourages sodium and calcium loss in the kidney
Why is the use of glucocorticoids beneficial in the treatment of hypercalcaemia?
Decrease absorption of calcium from intestine, reduce bone resorption of calcium, and enhance calcium excretion from kidneys
Why is the use of bisphosphonates beneficial in the treatment of hypercalcaemia?
Inhibit osteoclast resorption of bone (but are not short term drugs)
At what level of hypocalcaemia are clinical signs usuallly detected and what response is required?
<1.5mmol/L, treatment must be initiated as quickly as possible - quick deterioration
