The UCCR is a useful screening test for canine hyperadrenocorticism as a low (normal) result makes Cushing's unlikely (approximately 90% sensitivity). It is useful in those cases where hyperadrenocorticism is unlikely but needs to be definitely excluded. The test has low specificity (there are a lot of false positives). Further tests are needed to confirm that a high result is due to hyperadrenocorticism. It is thought that the test has similar sensitivity and specificity in cats but there are few published reports.
The urinary cortisol:creatinine ratio may be used as a screening test on urinary samples collected at home by the owners. Patients with suspicious results may then be tested with the low dose dexamethasone test.
- Ratio < 10 x 106 Cushings ruled out
- Ratio 10 – 15 x 106 Equivocal result, retest
- Ratio > 10 x 106 Cushings may be present
Canine and feline
- Collect a morning urine sample
- Submit sample with a request for urinary cortisol and creatinine concentrations.