A 20-year old male castrated Welsh Pony was presented to Cornell University Equine and Farm Animal Hospital for evaluation of dental disease, dental fractures and intermittent mucopurulent drainage from the right nostril. The pony had been seen by multiple veterinarians over the previous year, and one of these had diagnosed fractures of cheek teeth and performed partial extractions of tooth fragments as well as an oral equilibration (“float”). Several courses of trimethoprim sulfadiazine were prescribed over a period of months, but the nasal discharge failed to resolve. The final, referring veterinarian attempted to pass an endoscope into the right nostril, but encountered an obstructive lesion in the right nasal passage. The pony was referred to Cornell for further diagnostics as well as advanced dental care. Extraction of two maxillary cheek teeth was performed by sinusotomy and repulsion, and large quantities of mucopurulent and caseous material were flushed from the right maxillary sinuses and right ventral conchal sinus. This paper presents an overview of an important disease process of the maxillary cheek teeth, the process of apical (“tooth root”) abscessation that can result in sinus infection, and the description of a dental extraction performed by punch repulsion and oral techniques.