FIGURE 1.

Initial ancillary diagnostic examinations of a 13-year-old Thoroughbred gelding presented with a bilateral nasal discharge. (a) Lateral head radiographs. Note the well-circumscribed soft tissue masses situated in the dorsal conchal sinuses and the fluid lines present within the caudal maxillary sinuses. Additional soft tissue opacities are visible in the ethmoidal region. (b) Endoscopic view of the left middle meatus. Note the red round mass extending from the left ethmoid region rostrally into the nasal cavity.