Comparison of urine dipstick, sulfosalicylic acid, urine protein-to-creatinine ratio and a feline-specific immunoassay for detection of albuminuria in cats with chronic kidney disease.

The performance of the urine dipstick, sulfosalicylic acid (SSA), and urine protein-to-creatinine (UPC) tests for the detection of albuminuria was assessed in cats with chronic kidney disease (CKD). Two hundred and thirty-nine urine samples from 37 cats with CKD were used. Test results were dichotomized as either positive or negative, compared with those for the feline-specific rapid urine albumin immunoassay and test performance variables calculated for each test. A positive urine dipstick (≥ trace) and positive SSA (≥ 5 mg/dl), positive SSA alone or ≥ 2+ urine dipstick alone were indicative of albuminuria. In these cases, protein quantification would be warranted if proteinuria/albuminuria is persistent. In the case of a negative urine dipstick result the addition of the SSA added little diagnostic value. Of the tests investigated, the single best test for the detection of albuminuria was the UP/C (≥ 0.2) in which either a negative or positive test result provided useful information.