The oxidation of meat-and-bone meal (MBM) and two different raw animal byproducts (before and after rendering) has been studied by wet air oxidation (WAO) and catalytic wet air oxidation (CWAO), which represents an alternative way of animal byproduct disposal. The degradation of organic compounds was monitored by dissolved organic carbon (DOC) analysis following the subcritical conditions (230-280 degrees C, 9.9-18.6 MPa), which has led to the degradation of up to 90% of the initial total organic carbon (TOC) and reached 99% within the presence of platinum as a catalyst for the oxidation of a raw non-defatted sample. The oxidation of organic compounds has been studied as a function of pressure and temperature and showed that the TOC removal increased at higher temperature and higher pressure favoring the mass transfer of oxygen and organic compound into the liquid phase. The byproducts of the oxidation were identified; acetic acid was the main refractory organic compounds representing approximately 50% of the final residual TOC. The major inorganic byproduct was identified as ammonia, which was quantitatively removed (98.9%) in presence of platinum catalyst supported over alumina in basic medium.