Evaluation of total and ionized calcium status in dogs with blastomycosis: 38 cases (1997-2006)

• Published in: Journal of the American Veterinary Medical Association Vol. 231; no. 10; pp. 1545 - 1549
• Main Authors: Crews, L.J, Sharkey, L.C, Feeney, D.A, Jessen, C.R, Ruska, T
• Format: Journal Article
• Language: English
• Published: United States 15-11-2007
• Subjects: Animals; Blastomyces dermatitidis; blastomycosis; Blastomycosis - blood; Blastomycosis - diagnosis; Blastomycosis - veterinary; blood chemistry; Blood Proteins - physiology; blood serum; calcium; Calcium - blood; Diagnosis, Differential; disease diagnosis; dog diseases; Dog Diseases - blood; Dog Diseases - diagnosis; Dogs; Female; hematologic tests; hypercalcemia; Hypercalcemia - blood; Hypercalcemia - diagnosis; Hypercalcemia - veterinary; hypocalcemia; Hypocalcemia - blood; Hypocalcemia - diagnosis; Hypocalcemia - veterinary; Ions; Male; Predictive Value of Tests; Reference Values; Retrospective Studies
• ISSN: 0003-1488; 1943-569X
• DOI: 10.2460/javma.231.10.1545

To determine blood ionized calcium (iCa) and serum total calcium (tCa) concentrations in dogs with blastomycosis and to evaluate whether serum tCa concentration, albumin-adjusted serum calcium concentration (AdjCa-Alb), and total protein-adjusted serum calcium concentration (AdjCa-TP) accurately predict iCa status.
Retrospective case series.
38 client-owned dogs with a cytologic diagnosis of blastomycosis.
Dogs were classified as hypocalcemic, normocalcemic, or hypercalcemic on the basis of blood iCa concentration, serum tCa concentration, AdjCa-Alb, and AdjCa-TP; classification on the basis of serum tCa concentration, AdjCa-Alb, and AdjCa-TP was compared with blood iCa concentration.
Except for 2 hypercalcemic dogs, all dogs had blood iCa concentrations within the reference interval. Use of serum tCa concentration overestimated hypocalcemia in 57.9% (22/38) of dogs and underestimated hypercalcemia in 1 dog. Use of AdjCa-Alb correctly reclassified all dogs as normocalcemic that were classified as hypocalcemic on the basis of serum tCa concentration, but failed to predict hypercalcemia in 1 dog. Use of AdjCa-TP correctly reclassified all but 2 dogs as normocalcemic that were classified as hypocalcemic on the basis of serum tCa concentration, and failed to predict hypercalcemia in 1 dog. No correlation was found between blood iCa concentration and serum concentrations of tCa, total protein, and albumin; AdjCa-Alb; or AdjCa-TP.
High blood iCa concentration was uncommon in dogs with blastomycosis. Hypoalbuminemia contributed to a low serum tCa concentration despite a blood iCa concentration within reference limits. The use of serum tCa concentration, AdjCa-Alb, and AdjCa-TP may fail to identify a small number of dogs with high blood iCa concentrations.