The esophageal worm of dogs and other carnivores, a red spiruroid nematode that occurs in nodules in the wall of the esophagus, stomach, and aorta of dogs, foxes, and wolves; intermediate hosts are various coprophagic beetles. Clinical symptoms occur only in very heavy infections, which are associated with esophageal carcinomata in dogs and with hypertrophic pulmonary osteoarthropathy. [L., fr. G. speira, coil, + G. kerkos, tail; L. lupus, wolf]