Sinus tract, dog
Sinus tract, dog
Sinus tract, dog

    A fractured deciduous left maxillary canine tooth in a puppy has resulted in endodontic disease, periapical disease, and formation of a sinus tract. Note the proliferative, friable circular lesion with a central draining opening above the permanent left maxillary first premolar.

Courtesy of Dr. Gregg A. DuPont.