This study was carried out since summer 1988, to investigate the filarial parasites of dog of around Tehran. The blood samples of 138 sheep dogs from south, south west, south east, north west and north east of Tehran were examined for the presence of microfilaria using modified knott method. The age and the sex of examined dogs were recorded. To identify microfilaria of Dirofilaria iminitis from that of Depetalonema reconditum different keys (Eslami, 1987, other, table 1) were used. Our findings revealed that 1.4% and 8.7% of the dogs harbored Dirofilaria immitis and Dipetalonema reconditum respectively. Low number of dogs infected with Dirofilaria immitis (2)did not allow us to evaluate the role of age and sex on this infection, whereas there was a significant relation between age and infection with D. reconditum but not with sex using Chi2 test and fisher test respectively.
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