Duplex Doppler measurements of renal blood flow in a dog with Addison's disease.

Abnormal intrarenal flow in a seven-year old female Tibetan terrier with Addison's disease was demonstrated by duplex Doppler examination. Abnormal flow may reflect renal vasoconstriction due to increased activity of the renin-angiotensin system. Although not pathognomonic, an increased resistive index (> 0.70) in an otherwise ultrasonographically normal kidney can be due to Addison's disease and the technique may prove valuable as a quick non-invasive tool in the management of this disease.