Some animals will have diarrhea. In animals surviving 4-5 hours or more, blood can be present in feces and is usually dark in color. As the disease progresses, depression is more pronounced and nervous signs, including convulsions, muscle rigidity, and arching of the back are common. An accurate diagnosis is important when considering losses due to Type C enterotoxemia. Assessment of signs of the disease in conjunction with post mortem examinations and laboratory findings are all important.
Blood frequently is present in the intestine.
Gas bubbles may or may not be present in the wall of the intestine. This condition can be confused with hemolytic E. coli infections, intestinal twists, such as torsions or volvulus, and intestinal congestion with blood accumulation occurring near death due to other reasons. Other causes showing similar signs also may be mistaken for this disease. Quality post mortem examinations and appropriate laboratory tests are critical. In the laboratory, stains of intestinal smears show large numbers of clostridial organisms and laboratory cultures reveal large numbers of Clostridium perfringens bacteria.