OBJECTIVES

The major features of the gross and microscopic pathology of the classical granulomas caused by Spirocerca lupi (Rudolphi, 1809) have long been described (1). In this study, 50 stray dogs (32 males and 18 females) have been examined for helminths at necropsy room and those infested with Spirocerca lupi were examined to determine the presence and prevalence of different pathological lesions.

MATERIALS

In this study, 50 stray dogs (32 males and 18 females) have been examined for helminths at necropsy room and those infested with Spirocerca lupi were examined to determine the presence and prevalence of different pathological lesions. After selecting those dogs infested with Spirocerca lupi, they were necropsied and, after collection, samples were fixed in 10% formalin and 5-6 microns microscopic sections were prepared and stained.

RESULTS

The prevalence of spirocercosis in this sample of stray dogs in Tabriz was 42 out of 50. Infection with Spirocerca lupi was confirmed at necropsy. There were different lesions associated with Spirocerca lupi in different organs such as oesophagus and aortic wall. Lesions in oesophagus were found as parasitic granulomas in the caudal part. We also found parasitic granulomas in the aortic wall as well as aortic aneurysm that might be caused by trauma to the wall by the granulomas. Other macroscopic findings of this study included hypertrophic pulmonary osteopathy (2,3,4,5). The microscopic findings in this study were the granulomatous lesions, which were highly cellular. Fibrocytes formed compact layers in the inner portions of the granulomas whereas they exhibited tendency to form whorls in the periphery. Many immature or embryonal cells with a syncytial appearance were often found in clumps. Mitotic figures were very common, and an abnormal type of cell division was observed.

CONCLUSION

Our results are similar to those arising from studies in other countries, particularly from the Republic of South Africa, China, France, Finland and Portugal (6,7). Infection with Spirocerca lupi is very common in tropical areas, where it is often found in 80 or even 100% of dogs. In the city of Tabriz, where we have studied the prevalence of canine spirocercosis, atmospheric conditions cause a prevalence of 84%. Lesions were often found in oesophagus and aorta. Infestation with Spirocerca lupi is an important problem that leads to neoplastic changes in oesophagus. It is thought that oesophageal neoplastic lesions may be caused by different growth factors such as FGF, PDGF (8,9). These growth factors maybe induce production of cell growth signals (FGF, PDGF) in the cells of granulomatous lesion due to Spirocerca lupi (9).