THE PREVALENCE OF DIROFILARIA-IMMITIS IN DOGS IN SYDNEY

Four hundred and four dogs from 9 pounds in Sydney were examined for c irculating microfilariae and antigens of Dirofilaria immitis. One hund red of these were also examined post mortem for adult heartworms. The prevalence of infection in the 404 dogs as shown by serology was 11.4% , and 5.9% had circulating microfilariae of D immitis. Adult heartworm s were present in 15 of 100 dogs. Dipetalonema reconditum microfilaria e were present in 3.7% of dogs. Dirofilariosis is still a common and i mportant parasite of dogs in the Sydney region and chemoprophylaxis is recommended.