Introduction: Dirofilaria immitis is a nematode that lives in right atrium and pulmonary vessels of dogs, cats and occasionally in humans as a zoonosis. There were a few reports about frequency of this parasite before 1985 in Iran. But further studies showed that this parasite had a high incidence in Eastern Azarbayjan, Ardebil and Fars states.

Material and Methods: These findings resulted from autopsy examinations. After inducing veterinary clinics associated to Azad University in Tabriz and Basmenj (a town near Tabriz) we encountered with more cases of Dirofilaria immitis in dogs. This information obtained from two separate studies. The most part of these findings obtained from autopsy of vagrant dogs during experimental courses and another finding obtained from domestic dogs that suffer from heart diseases. Diagnosis of Dirofilaria immitis infestation in second group was based on clinical examinations of heart and lungs, thorax radiographs, electrocardiography, blood examination and observing of microfilaria.

Results: Final results include 42 positive case in 224 autopsy (18.6%) and 6 cases of Dirofilaria immitis within 21 dogs with heart patients (28.5%). Four cases were sheepdog and two of them were kept in city.

Conclusions: Heartworm infection is spread by many different species of mosquitoes and the geographic extent of the disease is probably directly related to that of the susceptible mosquitoes. Since these states are near to jungle area and mosquitoes are not under control conditions, prevalence of disease is increasing. Infection in urban dogs shows that heartworm disease has extended to homes.

References

1.  Clarence AR. et al.(1989): Heartworm disease. in Textbook of veterinary internal medicine, Philadelphia, W.B.Saunders, p: 1163-1167

2.  Calvert CA. et al.(1983): Canine heartworm disease. in Current veterinary therapy VIII. Philadelphia, W.B.Saunders, p: 348-352

3.  Rawling CA.et al (1981): Development and resolution of pulmonary disease in heartworm infection. JAVMA. 17, p: 711-715