Spirocerca lupi esophageal granulomas in 7 dogs: Resolution after treatment with doramectin

Seven dogs with Spirocerca lupi esophageal granulomas were identified based on the site of involvement (ie, distal esophagus) and characteristic endos copic appearance. Six dogs presented with signs of esophageal disease and 1 dog was asymptomatic. Ova were only identified in the feces of 2 dogs. On thoracic radiographs, 4 dogs had evidence of a caudodorsal mediastinal mass , and 2 of these dogs had spandylitis of midthoracic vertebrae. On endoscop y, single esophageal nodules were observed in 5 dogs, 1 dog had 3 nodules, and 1 dog had 6 nodules. All 7 dogs were treated with doramectin at a dosag e of 200 mug/kg SC at 14-day intervals for 3 treatments. Dogs had physical and endoscopic examinations at 2, 4, and 6 weeks after treatment. By 6 week s, clinical signs had resolved in 6 dogs (1 dog was asymptomatic), and the esophageal nodules had completely resolved in 4 dogs, and incompletely reso lved in 3 dogs. Two dogs with incomplete resolution were treated again with doramectin at 500 mug/kg PO daily for an additional 6 weeks. Complete reso lution of the esophageal nodules was confirmed by endoscopy in all dogs. No dules had resolved in 4 dogs by 6 weeks, in 2 dogs by 12 weeks (after 6 wee ks additional daily oral therapy), and in 1 dog 22 months after the initial 200 mug/kg treatment regimen. No dog experienced adverse effects to the dr ug, and all symptomatic dogs have been free of disease for periods ranging from 3 to 4 years.