Introduction
- Persistently raised serum calcium.
- Cause : multiple causes including neoplasia, renal failure, granulomatous disease, hypoadrenocorticism, hypervitaminosis D and others.
- Diagnosis : serum biochemistry defines the syndrome, but other tests may be required to identify the underlying cause.
- Signs : may include anorexia, lethargy, weight loss, sometimes polyuria/polydipsia, and other signs dependant upon cause.
- Treatment : fluid therapy, frusemide diuresis, glucocorticoids, or surgery (e.g. for parathyroid neoplasms).
- Prognosis : variable according to cause, but persistent untreated hypercalcemia may lead to renal failure and organ mineralization.
Diagnosis
Clinical signs
- Hypercalcemia itself causes various signs:
- Polyuria/polydipsia, +/- dehydration (from direct effects of calcium on renal function of from renal mineralization).
- Weakness, lethargy, cardiac dysrhythmias (from reduced membrane excitability).
- Also gastrointestinal signs such as vomition and/or constipation.
- Underlying diseases may be associated with other signs such as:
Diagnosis
Differential diagnosis
Other causes of polyuria/polydipsia.
Other causes of weakness/lethargy
Sequelae
Prognosis
- Varies according to underlying disease.
- Paraneoplastic hypercalcemia has poorer prognosis.
- Surgical removal of parathyroid tumors has shown an excellent prognosis.
- Rodenticide intoxication has variable prognosis dependant upon dose absorbed and delay before therapy.
- Prognosis may be poor if hypercalcemia has resulted in soft tissue mineralization of lungs and/or kidneys.
Expected response to treatment
- Correction of hypercalcemia should result in improvement of directly related signs such as dehydration, azotemia, cardiac arrhythmia, and weakness.
- Other responses depend upon the underlying cause and the specific therapy initiated.
Reasons for treatment failure
- Non-resolvable neoplasia (in humoral hypercalcemia of malignancy).
- Soft-tissue mineralization in lungs and kidney causing respiratory failure or renal failure.
Sources
Publications
Refereed papers
- Bolliger APet al(2002)Detection of parathyroid hormone-related protein in cats with humoral hypercalcemia of malignancy.Vet Clin Pathol31(1), 3-8.PubMed
- Smith SA, Freeman LC, & Bagladi-Swanson M (2002)Hypercalcemia due to latrogenic secondary hypoadrenocorticism and diabetes mellitus in a cat.J Am Anim Hosp Assoc.38(1), 41-44.PubMed
- Midkiff AMet al(2000)Idiopathic hypercalcemia in cats.J Vet Intern Med14(6) 619-626.PubMed
- Sueda MT & Stefanacci JD (2000)Ultrasound evaluation of the parathyroid glands in two hypercalcemic cats.Vet Radiol Ultrasound41(5) 448-451.PubMed
- Savary KC, Price GS & Vaden SL (2000)Hypercalcemia in cats: a retrospective study of 71 cases (1991-1997).J Vet Intern Med14(2) 184-189.PubMed
- Anderson TE, Legendre AM & McEntree MM (2000)Probable hypercalcemia of malignancy in a cat with bronchogenic adenocarcinoma. J Am Anim Hosp Assoc36(1) 52-5.
- Mealey KL et al(1999)Hypercalcemia associated with granulomatous disease in a cat.J Am Vet Med Assoc215(7) 959-962.PubMed
- McClain HM, Barsanti JA & Bartges JW (1999)Hypercalcemia and calcium oxalate urolithiasis in cats: a report of five cases.J Am Anim Hosp Assoc35(4), 297-301.PubMed
- Kallet AJet al(1991)Primary hyperparathyroidism in cats: seven cases (1984-1989).J Am Vet Med Assoc199(12), 1767-1771.PubMed




