In order to investigate the value of the rabbit as an
experimental model for Chagas' disease, seventy one animals
were inoculated with different Trypanosoma cruzi strains and
routes. The rabbits were submitted to necropsy in acute
(earlier than three months of infection), recent chronic
(three to six months) and late chronic (later than six months)
Myocarditis, generally focal and endomysial, occurred in
94.1%, 66.7% and 70.8% of the infected rabbits respectively in
the acute, recent chronic and late chronic phases. The
myocardial inflammatory exudate was composed by mononuclear
cells, and also polymorphonuclear cells in the acute phase. In
most cases of the late chronic phase, the myocarditis was
similar to that described in the indeterminate form of human
chagasic patients. Initial fibrosis occurred in the three
phases but was more severe and frequent in the early chronic.
Advanced fibrosis occurred only in the late chronic phase.
Tissue parasites occurred only in the acute phase. The
digestive tract and skeletal muscles showed mild and
Our data indicate that experimentally infected chagasic
rabbits repeat some lesions similar to that of humans chagasic
patients, specially that of the indeterminate form. So, it may
be a useful, however not an ideal, model.