Background: Toxocara is mainly a parasite of animals. The disease is caused mainly due to accidental ingestion of Toxocara canis embryonated eggs and to a lesser extent T.cati eggs. Till now, there is no marker of severity of infection or treatment in toxocariasis. Aim of the study: The current work aimed at studying the role of liver enzyme aspartate transaminase (AST) and cardiac enzyme creatine kinase-MB isoenzyme (CK-MB) as markers of severity infection and treatment of toxocariasis in correspondence to serum immunoglobulin with study of histological cardiac effects of toxocariasis. Materials and Methods: Laboratory mice were divided into groups infected with different doses of Toxocara eggs. Sera were collected from each group before and after treatment for measurement of AST and CK-MB, as well as ELISA for anti-Toxocara immunoglobulin IgG. T test, ANOVA test and Pearson correlation tests were used to assess the results. Results: CK-MB was elevated significantly with infection and reduced significantly after treatment. The serum level of CK-MB also correlated significantly and positively with parasite load. Conclusion: CK-MB can be used together with anti-Toxocara IgG in diagnosis and CK-MB can be a  good markers of treatment and parasite load in toxocariasis.