The epidemiology of Dirofilaria immitis infection in outpatient dogs at Chiang Mai University Small Animal Hospital, Thailand.

Five hundred eighty-nine dog blood samples from the small animal hospital of Chiang Mai University were examined for Dirofilaria immitis prevalence using a microhematocrit tube technique for microfilaria detection. In parallel, a once a month follow-up study on 36 D. immitis negative dogs was conducted to detect the time of acquiring infection in each animal.