The use of alpha blockade in the treatment of congestive heart failure associated with dirofilariasis and mitral valvular incompetence.

Four dogs with congestive heart failure associated with dirofilariasis and mitral valvular incompetence initially responded to treatment with digoxin or etamiphylline camsylate, and frusemide but became refractory to this therapy and were in cardiac decompensation. Frusemide dosage was increased and the alpha adrenoreceptor blocking drug prazosin hydrochloride was added to the therapeutic regime. Six weeks later all dogs were stabilized and their clinical condition was markedly improved.