This study aimed to evaluate the diagnostic value of Doppler ultrasound parameters of the hepatic artery, portal vein, and interlobar artery as well as the potential use of miRNA-122 for the diagnosis of acetaminophen-induced acute hepatic injury in dogs. Ten healthy mongrel dogs were orally administered 200 mg/kg body weight of acetaminophen daily for ten days. Clinical, Biochemical, Ultrasonographic, and Doppler ultrasonographic examinations were performed for all dogs on zero day before induction, 3^rd day, and the 10^th day of induction. The results of the current study showed that depression, dullness, and jaundice signs appeared in dogs on the 10^th day of induction. Significant increase (P<0.05) in the level of ALT, AST, ALP, BUN, Creatinine Cholesterol, triglycerides, and total bilirubin coincident with a significant decrease in levels of total protein, and albumin at the same time. The measurement of miRNA-122 showed its elevation at 6.34-fold on the 3^rd day, and 9.64-fold on the 10^th day of induction. Ultrasonographic findings revealed increased echogenicity of liver parenchyma on the 3^rd day and 10^th day of induction. The resistive index value of the portal vein, hepatic artery, and renal interlobar artery showed a significant increase(P<0.05) on the 3^rd day, and 10^th day of induction. The results of the current study revealed that Doppler ultrasonography is a useful diagnostic tool for early diagnosis of acute liver injury in dogs, and miRNA-122 could be used as a biomarker for early diagnosis of drug-induced acute liver injury in dogs.