Disorders associated with

Question 1

Mechanisms of hypocalcemia

Answer 1

• Decreased protein binding (hypoalbuminemia)
  -Decreased PTH
  -Inadequate mobilization from bone or intestinal absorption
  -Excess urinary excretion
  -Multifactorial/ idiopathic

Question 2

Decreased PTH mechanisms

Answer 2

-Primary hypoparathyroidism
-Hypomagnesemia (regulates adenylate cyclase in cellular response to PTH)

Question 3

Mechanisms of inadequate mobilization from bone or intestines

Answer 3

-Nutritional hypocalcemia
-Hypovitaminosis D
-Hypercalcitonism
-Hypoparathyroidism

Question 4

Causes of hypovitaminosis D

Answer 4

-Renal diseases
-GI disease
-Exocrine pancreatic insufficiency
-Vitamin D receptor defect

Question 5

Chronic renal disease hypovitaminosis pathophysiology

Answer 5

Decreased 1a-hydroxylase-> inactive vitamin D not converted to 1,25 DHC so there is decreased Ca absorption and bone resorption-> decreased plasma fCa and eventually -> decreased nephrons and GFR-> phosphate retention leads to increased Ca/Phos complexes and decreased plasma fCa-> leads to increase PTH that tries to get everything back WRI

Question 6

Excess urinary excretion of Ca

Answer 6

-Ethylene glycol toxicity
-Furosemide

Question 7

Multifactorial hypocalcemia

Answer 7

-Pregnancy, lactation, parturient hypocalcemia
-Metabolic alkalosis (PTH resistance, increased renal excretion)
-Pancreatitis (glucagon release)
-Urinary tract obstruction
-Sodium phosphate enemas in cats (complexing with P, increase excretion of P)
-Myopathies especially equine (decreased intake and reabsorption in kidney, moves into cell, lost in sweat)
-Sepsis (PTH resistance)
-Cantharidin (blister beetle) toxicosis