CT Diagnosis of Equine Sinusitis: Revealing a Hidden Dental Abscess

A 10-year-old TB mare was referred for evaluation of persistent right‑sided purulent nasal discharge that failed to respond to antibiotics. Despite significant nasal drainage, upper airway endoscopy was unremarkable, leaving the underlying cause unclear.

A standing CT of the head was performed to further investigate.

CT imaging revealed:

  • Clear asymmetry between the sinus compartments

  • Air‑filled sinuses on the unaffected side

  • Fluid-filled, opaque sinuses on the right

  • Evidence of periodontal disease

  • Findings consistent with a periapical abscess causing secondary sinusitis

This case highlights:

  • The diagnostic value of CT when radiographs are difficult to interpret

  • The limitations of standard skull radiography in complex sinus and dental disease

  • How advanced imaging can rapidly localize pathology and guide treatment

david ergun