The signs of esophagostomosis are anorexia, loss of body weight, diarrhea, and sometimes edema. A moderately severe normocytic, normochromic anemia appears, together with a decrease in plasma protein, mainly albumin. Considerable exudation of tissue fluids and plasma proteins from the intestinal lesions and hemorrhages caused by larval emergence contributes to the hypoproteinemia and anemia. This is exacerbated by impaired coagulation. Reduced growth or loss in condition is mainly the result of the interaction between protein effusion into the gut and loss of appetite. Diarrhea presumably results from the loss of absorption capacity of the colon. It would appear that secondary complications and bacterial migration play important parts in the disease.
The two common species found in pigs are O. quadrispinulatum and O. dentatum. Though the parasites themselves are generally highly prevalent, clinical esophagostomosis is not common in pigs.