Dental Malocclusions – Definition

Mandibular brachygnathism (“parrot mouth” or MAL2) is the condition in which the upper incisors protrude more rostrally than the lower incisors, resulting in no occlusal contact between upper and lower central incisor teeth. Mandibular prognathism (“sow mouth,” “monkey mouth” or MAL3) is the condition in which the lower incisors protrude more rostrally than the upper incisors, resulting in no occlusal contact between upper and lower central incisor teeth. The AAEP (and many breed organizations) consider these conditions undesirable heritable traits, which should be considered before breeding individual horses with these malocclusions.   

Revised by AAEP board of directors in 2024.