Spirocercosis and its complications in stray dogs in Shiraz, southern Iran

Spirocerca lupi is accepted in Veterinary Medicine as the cause of true malignancies in dogs. Aortic lesions and esophageal nodular granulomas are pathological lesions of spirocercosis that are considered to be pathognomic for this disease. Post mortem and histopathological studies of 105 stray dogs both male and female of different age groups from various residential areas were performed and their esophagus were examined for any lesions and helminthic parasites. Twenty dogs (19.04%) were infected with S. lupi. The infection rate was significantly higher in dogs greater than one year old (23.5%) and in western areas (36.4%) with similar prevalence rate in males and females. At histopathologic level, two isolate but closely related fibrosarcoma masses were situated at the distal portion of the thoracic esophagus of one dog and in the site of junction of esophagus and stomach of another one. Metastasis were observed in the lung and mediastinal lymph nodes of one of the dogs. Despite presence of large population of stray dogs little information is available about S. lupi in this country, so this study was undertaken to obtain an overall picture of this infection in stray dogs of Shiraz area, southern Iran.