Although cardiac failure occurs frequently in thiamine-deficient human beings (beriberi1), it is rarely encountered in animals with experimental thiamine deficiency. MacCarrison2 and Findlay3 observed hydropericardium in an occasional pigeon allowed to eat a thiamine-deficient ration ad libitum. Other indications of cardiac failure were lacking, however, and these experiments were done so early that it was impossible to exclude other contributing nutritional causes. More recently, signs and symptoms of cardiac failure have been produced in thiamine-deficient dogs.4 Bradycardia has been noted in thiamine-deficient pigeons,5 with and without abnormal electrocardiograms, whereas tachycardia has been observed in thiamine-deficient dogs.6 In rats bradycardia has been observed by some investigators,7 but others8 have expressed the opinion that this might be due to concomitant starvation.
In a recent paper9 we have pointed out that the symptoms of experimental thiamine-deficiency in pigeons vary greatly depending on the form of the deficiency. In pigeons that are