Pigs do not possess horns, which are a feature found on a distinct group of mammals. The structures often mistaken for horns are actually specialized teeth, a confusion that stems from their prominent size in certain pig species.
The Definitive Answer: Horns vs. Tusks
True horns are permanent structures composed of a bony core arising from the skull, covered by a sheath made of keratin (the protein found in human fingernails and hair). These appendages are found on ruminant artiodactyls, such as cattle, goats, and antelopes. Horns grow continuously throughout the animal’s life and are never shed, distinguishing them from temporary antlers.
Pigs (family Suidae) do not develop keratin-sheathed bony projections. The prominent structures seen on many pigs are tusks, which are elongated canine teeth that protrude outside the mouth. Tusks are made of dentin and enamel, and they grow from the jawbone, not the skull. This fundamental difference in origin means horns are modified skull projections, while tusks are modified teeth.
Anatomy and Function of Pig Tusks
A pig’s tusks are their permanent canine teeth, which grow continuously, particularly in males, or boars, due to an open root. Both upper and lower canines develop into tusks, with the lower set often growing larger and sharper. In wild boars, the lower tusks are sometimes called “cutters” because they develop a razor-sharp edge from constant friction against the shorter upper tusks, known as “whetters”.
These specialized teeth serve multiple functions for survival and social structure. Tusks are used as tools for rooting, allowing pigs to dig into the soil to find underground food sources like roots and invertebrates. They are also used for defense against predators and for establishing social hierarchy. During the mating season, boars use their tusks to fight rivals and assert dominance over breeding rights.
Wild Relatives and Misidentification
The perception that pigs have horns often comes from observing certain wild relatives whose tusks are highly visible and bizarrely shaped. Wild boars, warthogs, and babirusas all possess pronounced tusks that can appear horn-like from a distance. Warthogs, for example, have two pairs of tusks that curve outward dramatically and are often viewed alongside their large facial warts, leading to confusion.
The most unusual example is the Babirusa, or “deer-pig,” found in Indonesia. The male’s upper canine tusks grow upward, piercing the skin of the snout and curving back toward the forehead. These remarkable, spiraling teeth can look like a set of horns growing from the face, which is the source of the species’ Indonesian name.