Hypoparathyroidism in Cats

Overview:

The parathyroid glands are small endocrine (hormone producing) glands located in the neck behind the thyroid gland. They produce parathyroid hormone (PTH) which is responsible for increasing calcium levels in the blood. This is done by increasing calcium absorption from the digestive tract, taking calcium from the bones & suppressing calcium loss from urine.

Hypoparathyroidism is a medical condition in which the parathyroid hormone is either greatly decreased or absent. This results in hypocalcemia (low blood calcium levels).

The most common cause of hypoparathyroidism in cats is the accidental injury or removal of the parathyroid gland during the removal of the thyroid glands to treat hyperthyroidism. Idiopathic atrophy and immune-mediated parathyroiditis also seen (uncommon). [1]

Symptoms of hypoparathyroidism:

Symptoms relate to hypocalcemia brought on by the reduction/halt to parathyroid hormone levels & include;

• Restlessness

• Neuromuscular irritability such as nervousness, whiskers twitching, facial rubbing, tetany (involuntary muscle contractions)

• Lethargy

• Stiff legged gait

• Panting

• Increased respiration rate

• Anorexia

• Fever

• Convulsions

Diagnosis of hypoparathyroidism:

Your veterinarian will perform a complete physical examination & obtain a medical history from you. Recent thyroidectomy would raise his index of suspicion of hypoparathyroidism. Further tests he may wish to perform include;

• Complete blood count & biochemical profile to rule out other possible medical conditions. This may reveal low blood calcium levels & high blood phosphate levels.

• Serum PTH may show low or undetectable levels.

• Exploratory surgery may reveal atrophied or absent parathyroid glands.

Treatment of hypoparathyroidism:

Medical management to treat hypocalcemia includes;

Emergency:

• Slow intravenous administration of calcium gluconate.

Maintenance:

• Vitamin D assists in the absorption of calcium, and therefore may also be given.

• Once the cat has stabilised, oral administration of calcium gluconate.

• ECG to check for cardiac abnormalities

References:

Vet Connect