Evaluation of the Pre-Renal Azotemia and Acute Tubular Necrosis in Puppies by Doppler Ultrasonography

The diagnosis of pre-renal azotemia from acute tubular necrosis (ATN) is very important in order to choose the appropriate treatment method. Considering that urinary diagnostic indices are usually not very reliable due to the use of crystalloids and diuretics, a fast and accurate diagnostic method can significantly help the treatment of these patients. This study was designed and implemented in order to investigate the diagnostic value of Doppler ultrasound in differentiating pre-renal azotemia from ATN.

Fourteen puppies of different breeds that did not receive any fluids and were referred to the specialized small animal clinic of the Faculty of Veterinary Medicine of the Islamic Azad University, Urmia Branch due to oliguria or anuria were evaluated. In the first 24 hours after admission and in the recovery phase of acute kidney failure, ultrasound was performed and resistance index (RI) was measured in them. Based on history, clinical course and laboratory findings, acute renal failure (AFR) was divided into two categories: pre-renal azotemia and ATN, and appropriate treatment were given.

The sensitivity and specificity of the RI in differentiating these two conditions were calculated. At the RI cutoff point of 0.75, the sensitivity and specificity of ultrasound were calculated as 92.1% and 86.5%, respectively.

According to the obtained results, Doppler ultrasound can be helpful in differentiating pre-renal azotemia from ATN in puppies. At the cutoff point equal to 0.75, RI has the highest diagnostic accuracy.