Canine spirocercosis leading to fatal aortic rupture: A case report

Abstract

Spirocercosis, caused by the nematode Spirocerca lupi, is a prevalent and often insidious parasitic condition in canines in tropical and subtropical regions. This report details a fatal case of aortic aneurysm and rupture in a four year-old non-descript breed dog with a history of exercise intolerance. The disease, transmitted via intermediate coprophagous beetles and paratenic hosts, typically presents with varied clinical signs but can lead to life-threatening outcomes like aortic rupture. Post-mortem examination revealed severe hemothorax, pale mucous membranes, and characteristic aortic nodules (1-2 cm) with hemorrhage, necrosis, and coiled, reddish adult worms. This confirmed spirocercosis as the cause of death due to aortic aneurysm and rupture leading to hypovolemic shock. The literature review highlights the epidemiology, with a higher incidence in outdoor, large breed dogs, and diverse clinical manifestations ranging from subclinical esophageal dysphagia to neoplastic transformation and osteoproliferative abnormalities. Diagnosis often relies on fecal examination and advanced imaging. Treatment primarily involves avermectins, though early diagnosis remains challenging. This case underscores the critical importance of a high index of suspicion and multimodal diagnostic approach for spirocercosis in endemic areas to prevent such catastrophic outcomes and improve canine welfare.