In the course of routine postmortem examinations of rabbits infected with Treponema pallidum, six cases of pronounced granulomatous myocarditis were encountered. Treponemata were not demonstrated in the lesions, but the clinical history, and the gross and microscopic appearance of the lesions seemed to warrant a diagnosis of syphilitic myocarditis. The lesions measured 1.0 cm. or more in diameter and histologically were practically identical with those described by Warthin in cases of syphilitic myocarditis in man.
These are the first cases of syphilitic myocarditis or of visceral syphilis in the rabbit that have been reported.