title: Association of Hypercalcemia Before Treatment With Hypocalcemia After Treatment in Dogs With Primary Hyperparathyroidism.
abstract: BACKGROUND
  Development of hypocalcemia after treatment of hyperparathyroidism results in increased costs and risk of poorer outcomes. Previous studies have shown conflicting data about predictors of hypocalcemia after these procedures.
  
  
  OBJECTIVE
  The objective of this study was to investigate whether ionized calcium (iCa) concentrations before treatment are predictive of hypocalcemia or its clinical signs after surgical removal or heat ablation in dogs with primary hyperparathyroidism.
  
  
  METHODS
  Fifty-four dogs with primary hyperparathyroidism (29 female, 25 male; 49 retrospective, 5 prospective).
  
  
  METHODS
  Dogs were enrolled if they met the inclusion criteria: persistent hypercalcemia (iCa >1.41 mmol/L) due to primary hyperparathyroidism and absence of preemptive calcitriol treatment. All dogs were treated with parathyroidectomy (n = 37) or percutaneous ultrasound-guided heat ablation (n = 17). After treatment, iCa was monitored twice daily until plateau or intervention.
  
  
  RESULTS
  There was a moderate correlation between before-treatment hypercalcemia and after-treatment hypocalcemia. The prospective study was terminated due to ethical concerns given findings in the retrospective section. All dogs were placed into groups according to their pretreatment iCa: 1.46-1.61 mmol/L, 1.62-1.71 mmol/L, iCa 1.72-1.81 mmol/L, or >1.81 mmol/L. After treatment, the mean lowest iCa for each group, respectively, was 1.19, 1.18, 1.13, and 1.01 mmol/L. There was a significant association between higher group and proportion of dogs with iCa <1.00 mmol/L (P = .014).
  
  
  CONCLUSIONS
  This study demonstrates a moderate correlation between iCa concentration before treatment and hypocalcemia after treatment. Dogs with higher initial iCa concentrations should be treated to prevent rapid decline and development of clinical hypocalcemia.
authors.affiliation: Department of Medicine and Epidemiology, University of California, Davis, CA.
authors.forename: J D
authors.initials: JD
authors.lastname: Dear
authors.affiliation: Department of Population Health and Reproduction, University of California, Davis, CA.
authors.forename: P H
authors.initials: PH
authors.lastname: Kass
authors.affiliation: Department of Medicine and Epidemiology, University of California, Davis, CA.
authors.forename: A M
authors.initials: AM
authors.lastname: Della Maggiore
authors.affiliation: Department of Medicine and Epidemiology, University of California, Davis, CA.
authors.forename: E C
authors.initials: EC
authors.lastname: Feldman
mesh_terms: D000818:Animals; D002118:Calcium / Q000097:blood; D017115:Catheter Ablation / Q000009:adverse effects / Q000662:veterinary; D002413:Cations, Divalent; D004283:Dog Diseases / Q000097:blood / Q000601:surgery*; D004285:Dogs; D005260:Female; D006934:Hypercalcemia / Q000662:veterinary*; D049950:Hyperparathyroidism, Primary / Q000601:surgery / Q000662:veterinary*; D006996:Hypocalcemia / Q000209:etiology / Q000662:veterinary*; D008297:Male; D016105:Parathyroidectomy / Q000009:adverse effects / Q000662:veterinary; D011446:Prospective Studies; D012189:Retrospective Studies
chemical_list: D002413:Cations, Divalent; D002118:Calcium
keywords: Ablation; Calcitriol; Endocrinology; Parathyroid glands; Parathyroidectomy