Abstract
Pronounced rhonchi were observed in a 7.5-year-old Holstein cow. A large mass with fluctuations was also
noted in the buccal region by palpation. An X-ray examination of the head revealed liquid retention in the
maxillary sinus and osteolysis around the root of the upper third molar. These findings suggested that the
mass might be a secondary abscess followed by odontogenic maxillary sinusitis. A necropsy revealed that the
mass was a maxillary sinus abscess. The X-ray examination of the head was useful for the diagnosis of
maxillary sinus abscess.
