Canine spirocercosis.

Spirocercosis (Spirocerca lupi) in dogs has been mostly associated with the presence of esophageal granulomas that may transform to sarcomas; aortic aneurysms; mid-thoracic spondylitis; hypertrophic osteopathy; salivary gland necrosis; and pyothorax. Although the disease is frequently subclinical, esophageal dysphagia manifested by regurgitation, odynophagia, and hypersalivation is considered the clinical hallmark. Diagnosis should combine fecal analysis, thoracic radiography, and esophagoscopy to look for parasite ova, spondylitis or posterior mediastinal masses, and parasite nodules or tumors, respectively. Two avermectins, doramectin and ivermectin, have been effective in the treatment of canine spirocercosis, resulting in clinical remission, regression, or elimination of esophageal granulomas and cessation of egg shedding.