Disease of the conchal bullae should be considered as a potential cause of chronic unilateral nasal discharge in horses. Clearance of empyema within these bullae is unlikely to occur through lavage of the paranasal sinuses alone. Where necessary, fenestration of the bulla allows physical removal of infected material.

Background: Equine maxillary cheek teeth infundibulae are frequently affected by developmental and acquired disorders, but the computed tomographic (CT) imaging features of normal and abnormal infundibulae remain incompletely understood. Objective: To examine infundibulae with various grades of occlusal caries and control teeth by standard CT in order to assess the prevalence, type and location of subocclusal infundibular lesions present. Study design: Ex vivo original study. Methods: One hundred maxillary cheek teeth, including 82 with, and 18 without infundibular occlusal caries, were extracted from horses of different ages and imaged by standard CT; 8 teeth were also imaged by MicroCT. Images were later assessed by Osirix® and the prevalence, characteristics and sites of infundibular lesions were assessed. Results: Teeth with shorter infundibulae (i.e., Triadan 09 position and older teeth) were more likely to have occlusal caries, as were the rostral infundibulae. Subocclusal developmental infundibular lesions, including cemental hypoplasia and caries, were present in 72% of infundibulae without occlusal caries. CT imaging confirmed two main patterns of developmental cemental hypoplasia, i.e., apical cemental hypoplasia usually involving the full width of the apical aspect of the infundibulum and central linear hypoplasia involving the central aspect of the infundibulum over most of its length, and combinations of these types. These developmental lesions could later be affected by (acquired) infundibular caries once occlusally exposed due to normal wear. Some “normal-sized” (i.e., circa 1 mm diameter) occlusal central vascular channels expanded subocclusally to the dimensions of central linear defects. Main Limitations: No clinical histories or accurate ages were available for these teeth. Conclusions: Hypoplastic cemental lesions, including at central linear, and apical sites, are common even in clinically normal maxillary cheek teeth infundibulae and caries can occur when these lesions contact the occlusal surface. Central linear defects are not always clearly distinguishable from “normal” central vascular channels.

Summary Due to their long hypsodont reserve crowns, extraction of equid cheek teeth can be difficult and result in more complications than the extraction of their shorter brachydont counterparts although the more recent resumption of oral extraction has greatly reduced such complications. The more common post‐extraction sequelae in equids include non‐healing alveoli due to retained dental or alveolar sequestrae which may lead to oromaxillary or oronasal fistula formation, chronic external sinus tract formation or osteomyelitis of the supporting bones. Collateral damage to adjacent teeth has also occasionally been reported during dental repulsion. Systemic complications following equine cheek tooth extraction have been infrequently described, including a small number of cases of exodontia‐related bacterial meningioencephalitis. This is surprising, as dental manipulation can lead to bacteraemia in many species, including horses. Infections at distant sites related to the spread of dental pathogens have been well described in humans and in small animals. This report describes deep abscessation of the masseter muscles followed by extensive thrombophlebitis of the jugular, facial and rostral cervical veins following oral cheek tooth extraction in a pony affected by pituitary pars intermedia dysfunction (PPID) that was successfully treated by abscess drainage and thrombectomy of the affected veins.