Serum Ca, PTH, Vitamin D, PTHrP

Ca, P

Which two ions are part of a routine chemistry profile, should be interpreted together, are controlled by the same hormones, and have concentrations that affect each other?

D3

What vitamin is also called Cholecalciferol and is converted from 7-Dehydroxyl cholesterol by the effect of UV light on skin?

Intestine

On what organ/s does Vitamin D act, affecting the absorption of P, and Ca? It balances the intake of Ca in the diet.

Parathyroid

What hormone, abbreviated PTH, has two primary sites of action: kidney (1alpha-hydroxylase) and bone (Ca/P release)?

FGF23

What signal molecule, also called the fibroblast growth factor, primarily affects P levels and acts on osteocytes? It indirectly influences Ca metabolism, lowers P levels and inhibits vitamin D production to increase renal excretion. It also helps maintain a balance between Ca and P in the body, but in CKD high levels of it cause heart and more kidney damage.

Ca, P

What two ions are released from bone on the action of PTH?

D

FGF23 action inhibits the production of what vitamin? This increases renal excretion.

10

What percentage of Ca is complexed as Ca phosphate and Ca citrate?

40

What percentage of Ca is bound to albumin? Low albumin will produce the condition hypoalbuminemic hypocalcemia, and this Ca does not pass through the glomeruli.

50

What percentage of Ca is free ionized Ca, is the active form, and is altered by pH? It is also available as a special assay test.

Yes

Do Heparin, EDTA, and Citrate interfere with Ca measurement? An anerobic serum vacutainer tube is the only method of collection for this test, it is allowed to clot and is separated by centrifugation, and is transported on ice.

Decrease

If a sample for a Ca test is exposed to air, the pH will decrease, bound Ca will increase, and free Ca will do what?

Increase

Will acidosis cause an increase or decrease in free Ca? H will bind to the negatively charged albumin.

Decrease

Will alkalosis cause an increase or decrease in free Ca?

Immunoreactive

What type of PTH is stimulated by decreased fCa and Vit D, and is inhibited by increased fCa and Vit D?

Increases

PTH will have what effect on fCa by promoting mobilization and absorption?

Decreases

PTH will have what effect on P by promoting renal excretion?

Yes

Are most disorders of increased total Ca the same as increased fCa?

Hypoalbuminemia

Decreased total Ca due to what blood protein condition does not affect fCa? Increased binding of Ca to anions (proteins, citrates, sulfates) will also not affect it.

Ca

What ion moves across membranes, is a co-factor in chemical reactions and the coagulation cascade, and helps activate cell secretion and contraction?

12.8

Hypercalcemia is defined as consistent elevations in total calcium over how many mg/dL? This is the same as over 3.2 mmol/L. Toxins can elevate Ca within 24 hours to levels much higher than this.

Hypocalcemia

Muscle tremors, convulsions, seizures, ataxia, flaccid paralysis, weakness, and tetany are all clinical signs of what blood ion condition in dogs?

Hypercalcemia

Shivering, lethargy, depression, inappetence, muscle weakness, constipation, bradycardia, and arrhythmias are all clinical signs of what blood ion condition in dogs? PU/PD, dilute urine, renal tubular injury, vomiting, and diarrhea can also occur.

Acute

What causes of hypercalcemia include toxins like plants, Vit D supplements, and Vit D rodenticides, exogenous hypervitaminosis D, and decreased urinary excretion due to AKI in horses and CKD in dogs and horses?

Exogenous

What type of hypervitaminosis D is an acute cause of hypercalcemia?

Chronic

What causes of hypercalcemia include neoplasias like HHM, apocrine carcinomas, endogenous hypervitaminosis D, granulomatous inflammation, idiopathic causes in cats, and decreased urinary excretion due to CKD in horses and hypoadrenocorticism in dogs? Primary hyperparathyroidism can also be a cause although it is rare.

Endogenous

What type of hypervitaminosis D is a chronic cause of hypercalcemia?

Pseudohypercalcemia

What blood ion condition is an artefact of lipemia?

Xylitol

What sugar substitute can cause acute toxic hypercalcemia in dogs? It causes potent release of insulin from the pancreas and profound hypoglycemia.

Thiazide

What group of diuretics cause hypercalcemia by direct absorption of Ca through the distal tubules?

Addison’s

What disease is a chronic cause of hypercalcemia and acts by decreasing renal excretion of Ca? It may also increase Ca resorption from the gut.

Osteolytic, Granulomatous

What two diseases/types are chronic causes of hypercalcemia, along with schistosomiasis, blastomycosis, histoplasmosis, and coccidioidomycosis?

Pseudohyperparathyroidism

What cause of hypercalcemia is one of the most common and involves HHM in canines and feline humoral hypercalcemia of malignancy? Neoplastic cells produce this condition/signal causing increase in total Ca. It is caused by a molecule called PTHrP (parathyroid hormone related-protein.

HHM

What tumor (three letters) in dogs is most often seen as lymphomas, apocrine gland adenocarcinomas, and multiple myelomas, along with carcinomas originating in various tissues and primary/metastatic bone tumors? It is a chronic cause of hypercalcemia. In horses it is seen as a lymphoma, ameloblastoma, gastric/ocular SCC, or adrenal cortical carcinoma.

Low

In HHM tumors causing hypercalcemia, will PTH be low or high? P will be low and PTHrP will be high.

Primary

What type of hyperparathyroidism is seen as increased fCa, decreased P, increased PTH, and decreased PTHrP?

HHM

What cause of hypercalcemia is seen as increased fCa, decreased P and PTH, and increased PTHrP?

Renal

Which type of hyperparathyroidism is shown as decreased fCa, increased or normal P, increased PTH, and decreased PTHrP?

Developmental

What causes of hypocalcemia include hypoalbuminemia, rumen overload, increased renal excretion, and urinary tract obstruction?

Metabolic

What causes of hypocalcemia include decreased Mg, lactation, pregnancy, eclampsia, and parturient causes?

Nutritional

What causes of hypocalcemia include hypovitamin D, causing rickets?

Toxic

What causes of hypocalcemia include blister beetles, and ethylene glycol?

Milk Fever

The clinical signs of hypocalcemia in cows are collectively called what condition?

Horses

In what animals will hypocalcemia appear as synchronous diaphragmatic flutter, tetany, and lactation tetany?

Eclampsia

What condition is caused by hypocalcemia and can occur in dogs, cats, ewes, sows, mares, and goats? It is the same as milk fever in cattle and is most common in small breed dogs.

Alfalfa

Hay made from what, when fed to horses, cattle, and sheep, can cause toxic hypocalcemia?

Oxalate

Plants rich in what, such as sorrel, oxalis, rhubarb, spinach, beets, cocoa, nuts, and berries can cause toxic hypocalcemia?

Hypoparathyroidism

What hormonal condition can cause hypocalcemia, although uncommonly?

Anions

Renal excretion of what, as well as renal excretion of Ca, and the use of Furosemide can cause hypocalcemia?

Hypocalcemia

Does pancreatitis cause hyper or hypo calcemia? It causes precipitation of Ca by forming salts with fatty acids released from peripancreatic fat by the action of lipase. Resistance to PTH can also occur along with it.

No

Does CKD in horses cause hypocalcemia?

Pseudohypovitaminosis D

What hormonal condition is a cause of hypocalcemia as it involves a congenital defect in the Vit D receptor gene even when Vitamin D is present?

Horse

What animal can have nutritional secondary hyperparathyroidism in a condition also known as bran disease as this feed is high in oxalates?

Yorkshire

What terriers are prone to hypocalcemia due to intestinal malabsorption?