Dogs that do not die develop ascites and hepatomegaly due to right side heart failure. Anorexia and diarrhea are also common. Neurologic signs including weakness and ataxia, suggesting distemper, are also common. ECG changes during the acute phase are variable. During the asymptomatic period between the acute and chronic phase of infection, ECG may be normal except for intermittent ventricular arrhythmia, often exacerbated by exercise.
Sudden death can occur due to fatal cardiac arrhythmia.
Trypanosomiasis should be considered in any dog with signs of myocarditis or cardiomyopathy. Felines are reported to be susceptible to infection but little is known of clinical disease in this species. Diagnosis is dependent on detecting trypomastigotes in peripheral blood films, lymph node aspiirates or impression smears, or isolation in susceptible laboratory animals or cell culture. Trypomastigotes are most common in peripheral blood during and just prior to the acute phase, being less common in the chronic phase. Treatment is effective with nifurtimox, although it is not approved in the U.S. Treatment with anti-inflammatory doses of glucocorticoids and other supportive measures are useful.