Primary Hypoparathyroidism

Question 1

How does low PTH lead to hypocalcemia and hyperphosphatemia?

Answer 1

Low calcium: less resorption from bone, decrease absorption from the intestines & kidneys
PTH not acting on the distal tubule –> less phosphorus excretion = hyperphosphatemia

Question 2

What happens to the CNS and PNS with hypocalcemia?

Answer 2

the nerves become hyperexcitable, so seizures, muscle tremors/fasciculations, and s tiff gait = common

Question 3

Other than surgery or trauma, what are some etiologies of primary hypoparathyroidism?

Answer 3

• idiopathic
• immune mediated

Question 4

What are some clinical signs of hypocalcemia?

Answer 4

• seizures
• tremors/ fasciculations
• stiff gait
• jaw champing/ facial rubbing
• tetany
• decreased appetite, vomiting, “weakness”, lethargy, and diarrhea

Question 5

At what calcium level would signs of hypocalcemia be noted?

Answer 5

tCa <7mg/dL or Ca2+ < 0.8mmol/L

Question 6

What ECG changes are noted with hypocalcemia?

Answer 6

ST/ QT interval prolongation

Question 7

What’s the main acute treatment for hypoparathyroidism?

Answer 7

IV calcium gluconate

Question 8

What’s the chronic treatment for hypoparathyroidism?

Answer 8

oral vitamin D analogue

Question 9

What’s the treatment goal?

Answer 9

to have serum Calcium just below or at the low end of the reference interval

Question 10

What’s the prognosis of dogs with hypoparathyroidism

Answer 10

excellent with dedicated and competent owners