The prevalence of Dirofilaria immitis in cats in Japan has been examin
ed since 1957. Twenty surveys involving a total of 3775 cats, conducte
d in two islands of Japan (Honshu and Kyushu), were studied. The surve
ys evaluated both stray (3617) and house (158) cats. Presence of D. im
mitis was detected at necropsy. The results show a prevalence of D. im
mitis varying from 0.5 to 9.5% for stray cats and from 3.0 to 5.2% for
house cats on the two islands. (C) 1998 Elsevier Science B.V.