© 2017 British Veterinary Association. A six-month-old male entire golden retriever was presented with an umbilical mass noted by the owners four days before. Clinical examination revealed fever (39.7°C) and an umbilical fistulised abscess. Abdominal palpation revealed a solid mass in the caudal abdomen. The ultrasonographic study confirmed the presence of an abdominal mass (7 cm in diameter) adhered to several abdominal organs, mild localised peritonitis and an umbilical defect. The mass was compatible with an abscess or a granuloma potentially associated with an urachal remnant. An exploratory laparotomy confirmed the suspicion. The mass was removed and the urachal remnant corrected. Histopathology revealed the presence of a granuloma with multiple necrotic areas and basophilic structures suggestive of bacterial infection. Few days after surgery, all clinical signs resolved completely. Urachal remnants are rarely reported in small animals. To the authors' knowledge, this is the first report describing such a severe presentation with complete resolution.