Objective: To evaluate the utility of commercially available reagent test strips for estimation of BUN concentration and detection of azotemia in pet rabbits (Oryctolagus cuniculus) and ferrets (Mustela putorius furo).
Sample: 65 blood samples from 53 rabbits and 71 blood samples from 50 ferrets of various health statuses.
Procedures: BUN concentrations were measured with a clinical laboratory biochemical analyzer and estimated with a reagent test strip. Results obtained with both methods were assigned to a BUN category (range, 1 to 4; higher categories corresponded to higher BUN concentrations). Samples with a biochemical analyzer BUN concentration ≥ 27 mg/dL (rabbits) or ≥ 41 mg/dL (ferrets) were considered azotemic. A test strip BUN category of 3 or 4 (rabbits) or 4 (ferrets) was considered positive for azotemia.
Results: Test strip and biochemical analyzer BUN categories were concordant for 46 of 65 (71%) rabbit blood samples and 58 of 71 (82%) ferret blood samples. Sensitivity, specificity, and accuracy of the test strips for detection of azotemia were 92%, 79%, and 82%, respectively, for rabbit blood samples and 80%, 100%, and 96%, respectively, for ferret blood samples.
Conclusions and clinical relevance: Test strips provided reasonable estimates of BUN concentration but, for rabbits, were more appropriate for ruling out than for ruling in azotemia because of false-positive test strip results. False-negative test strip results for azotemia were more of a concern for ferrets than rabbits. Testing with a biochemical analyzer remains the gold standard for measurement of BUN concentration and detection of azotemia in rabbits and ferrets.