Trypanosomiasis has been reported in dogs from Texas, Oklahoma, Louisi
ana, and South Carolina. We describe the first isolation and character
ization of Trypanosoma cruzi from a Walker Hound pup in Virginia that
also had postvaccinal distemper. The mother of the pup and 7 of its 8
siblings also were found to be infected with T cruzi, suggesting that
the parasite had been transmitted transplacentally or through lactatio
n. Parasitologic, serologic, histologic, and molecular methods were us
ed to establish the diagnosis of T cruzi infection in these dogs. In a
serologic survey of 12 dogs (including the sire of the pups) from the
area in which the index case occurred, none were found to have antibo
dies to T cruzi. However, 2 of a further 52 dogs from different areas
(to the index case), but in the same county, were seropositive to T cr
uzi. These findings indicate that canine trypanosomiasis is present in
an area of the United States not previously known to be enzootic.