Objective—To identify the geographic distribution of
babesiosis among dogs in the United States and
determine, for dogs other than American Pit Bull
Terriers (APBTs), whether infection was associated
with a recent dog bite.
Procedure—Canine blood samples submitted to the
North Carolina State University Vector-Borne Disease
Diagnostic Laboratory between May 2000 and
October 2003 for which results of a Babesia-specific
polymerase chain reaction assay were positive were
identified, and breed and geographic origin of dogs
from which samples were obtained were recorded.
History and hematologic abnormalities for dogs that
were not APBTs were recorded, and possible associations
with a recent dog bite were examined.
Results—Dogs positive for Babesia DNA were located
in 29 states and 1 Canadian province (Ontario).
Babesia gibsoni was the most commonly detected
species, with B gibsoni DNA detected in blood samples
from 131 of 144 (91%) dogs. Of the 131 dogs
positive for B gibsoni DNA, 122 (93%) were APBTs.
Of the 10 dogs positive for Babesia canis vogeli DNA,
6 were Greyhounds. In dogs other than APBTs, there
was an association between having recently been bitten
by another dog, particularly an APBT, and infection
with B gibsoni.
Conclusions and Clinical Relevance—Results document
an expansion of the known geographic range for
babesiosis among dogs in the United States. Testing
for babesiosis should be pursued in dogs with clinicopathologic
abnormalities consistent with immunemediated
hemolytic anemia or thrombocytopenia,
particularly if there is a history of a recent dog bite.
(J Am Vet Med Assoc 2005;227:942–947)