New Facial Glands in Domestic Pig and Warthog

Sebaceous scent glands, located in the upper lip beside the tusks, are reported in two species of suids. A preorbital gland similar to the tusk gland is also described in the warthog. Tusk-gland secretion is employed for scent-marking objects and could contribute to salivary pheromones emitted during sexual and agonistic encounters when boars champ and gnash their tusks.