7 CASES OF HEARTWORM-DISEASE (DIROFILARIASIS) IN DOGS IN THE NETHERLANDS

We present here the clinical history, diagnosis, and treatment of seve n dogs with dirofilariosis. All dogs were imported into the Netherland s after residing in an area in which dirofilariosis is endemic. In thr ee of these dogs the infection was occult, for the serological test wa s positive but there was no microfilaraemia. Weight loss, coughing, dy spnoea, and decreased exercise tolerance were the most prominent clini cal signs. Two of the dogs had the characteristic electrocardiographic and radiographic signs of enlargement of the right heart. Treatment w ith thiacetarsamide and ivermectin resulted in complete remission in s ix dogs. One dog died, presumably as a result of acute renal failure. In the past year (1992-1993) seven cases of canine dirofilariosis were diagnosed, nearly equal to the number in the preceding 10 years (n=9) . This most probably reflects the greater sensitivity of the serologic al diagnosis of dirofilariosis in comparison with identification of mi crofilariae in the circulation, but a real increase in the number of d ogs with dirofilariosis as a result of growing international traffic o f tourists accompanied by pets cannot be excluded.