Diagnostic Studies on Acetaminophen Toxicosis in Dogs

Seventeen apparently healthy mongrel dogs aged from 1-2 years were used in this study. Ultrasonographic, clinicopathological, cytological and histopathological changes associated with the uses of acetaminophen as maximum therapeutic and toxic doses were studied. The dogs were divided into three groups as follow; first group without receiving any treatment as a control group, second and third group was orally received 128 and 200 mg kg-1 B.W as a maximum therapeutic and toxic dose of acetaminophen, respectively. The experiment continued for 10 days, through which collection of samples from all groups of dogs was performed on the 3rd and the 10th day post treatment (p.t). Ultrasonographic examination revealed hyperechodensity of liver parenchyma at 3rd day in some dogs. The ultrasonographic changes became more pronounced in the third group at the 10th day (p.t) in liver parenchyma and renal cortex expressed by hyperechogenicity and disappearance of echogenic portal vein walls, especially in toxic dose of acetaminophen. The clinicopathological changes revealed the presence of hemolytic anemia. Increases activities of liver enzymes as well as serum bilirubin, blood glucose, blood urea nitrogen (BUN) and serum creatinine concentrations in all experimental dogs were observed. The cytological examination showed the presence of hepatic toxicity, hyperplasia of splenic tissue, vacuolation and degeneration of renal tubular epithelial cells and different degrees of bone marrow (B.M) hypocellularity. All the above mentioned changes were more pronounced in the toxic dosed group than in the maximum therapeutic dosed group in comparison to the control one. These results were correlated with ultrasonographic and histopathological findings.It was concluded that, acetaminophen should be used only in limited amounts for limited periods as its signs of toxicity appeared even with its therapeutic dose.