Porcine vomeronasal system: anatomy, development, receptor repertoire, and inflammatory change

The vomeronasal organ (VNO), a component of the accessory olfactory system, plays a critical role in pheromone detection in mammals and contributes to a wide range of behaviors, including reproduction and social communication. Pigs have emerged as an important species both in industry and research. To elucidate the VNO in domestic animals, this review summarizes the anatomical, histological, developmental, and pathological characteristics of the porcine vomeronasal system, with particular attention to its role during development and under inflammatory conditions.

The literature indicates that the porcine VNO, encased by vomeronasal cartilages, is located at the base of the nasal septum in the form of blind-ended tubes. Olfactory marker protein is clearly detected in receptor cells at the fetal stage, indicating that the VNO is functional. The morphological features of the pig VNO are like those of other ungulates, such as goats. Notably, molecular findings imply that the pheromone receptor repertoire is less extensive in pigs than in rodents. In addition, under certain environmental conditions and with aging, inflammatory responses may occur in the porcine VNO, potentially leading to pheromone perception dysfunction.

Collectively, these observations underscore the importance of the VNO, not merely as an accessory olfactory system but as a central organ that links environmental conditions, endocrine regulation, and reproductive performance. This highlights its relevance in clinical diagnostics and welfare-oriented livestock management.