Clinical value of amylase and its prognostic accuracy in guinea pigs (Cavia porcellus)

Abstract

Objectives: To retrospectively evaluate plasma amylase concentrations in client-owned guinea pigs (Cavia porcellus) and determine a possible association with mortality. Materials and Methods: Medical records of guinea pigs that had a biochemistry panel from four institutions were retrospectively reviewed. Guinea pigs were excluded from the study if plasma amylase concentrations were not measured or there was no follow-up 30 days after the initial biochemistry panel. Results: Two hundred seventy-eight guinea pigs were included. Odds of mortality were not linearly associated with increasing amylase concentrations, but higher mortality was seen with markedly elevated plasma amylase (1910 to 3985 U/L; 65.2% death). After multivariable adjustment, guinea pigs with markedly elevated plasma amylase concentrations were seven times more likely to die within 30 days compared to those with a concentration within the reference interval (1339 to 1573 U/L) (aOR: 7.98; adj. 95% CI: 3.29 to 19.35). In addition, BUN concentration higher than 62 mg/dL had a 29.97 times greater odds of 30-day mortality than those with a BUN concentration lower than 62 mg/dL (aOR: 29.97, adj. 95% CI: 3.78 to 237.65). The AUC of the ROC curve of amylase concentrations to predict 30-day mortality was 72.7% (95% CI: 65% to 79.9%). Clinical Significance: While the exact pathophysiology of changes in plasma amylase concentrations in guinea pigs is unknown, this enzyme has clinical significance, considering that markedly elevated plasma amylase concentrations were associated with a higher risk of mortality. The actual prognostic capacity of the enzyme alone is limited and should be evaluated as part of a full clinical picture.