Biological Characteristics
Ongoing studies are being conducted to determine distinguishable characteristics between domestic, feral, Russian and feral/Russian crosses through DNA testing, skull measurements, external body measurements, coat coloration patterns, bristles and other criteria. Much has been learned but definite determinants have not yet been developed. Therefore, it should be pointed out that the following descriptions are general and relative in nature.

Tusks which are found on the lower jaw, or mandible, can be extremely dangerous when put to use by a mature boar. The upper tusks, or witters, help keep the lower tusk razor sharp.

Description
In general, a feral hog looks like its domestic counterpart. Coat coloration patterns can vary from solid black, brown, blond, white, or red to spotted (various combinations of black, white, red, and brown) or belted. A belted hog has a white band across the shoulder and forelimbs. Feral hog bristle length is generally longer than a domestic hog but shorter than the hybrid or pure Russian. A feral hog can reach three feet in height and over 300 pounds in weight; however, the average sow weighs approximately 110 pounds and the average boar weighs 130 pounds.

A boar has four continually growing tusks that can be extremely sharp and may reach five inches before they are broken or worn from use. Tusks are used for defense and to establish dominance during breeding. A male feral hog also develops a thick, tough skin composed of cartilage and scar tissue on the shoulder area which is sometimes referred to as a shield. The shield develops continually as the hog ages and through fighting.

The pure Russian boar is generally light brown or black with a cream or tan color on the tips of the bristles. Its underside is lighter in color and its legs, ears and tail are darker than the rest of the coat. Its bristles are the longest of the three types of wild hogs. Pure Russian boars have longer legs and snouts and their head to body ratio is much greater than a feral hog. They also tend to have shorter, straighter tails.

Feral/Russian crosses exhibit combinations of features from both the feral and the Russian hogs. Bristle length in the hybrid is longer than the feral but shorter than the Russian. Hybrids exhibit the smallest bristle shaft diameters. Striped patterns on the young are sometimes thought to be an indicator of pure Russian or feral/Russian crosses; however, this pattern has also been found in feral piglets and therefore is not a reliable method of identification.

Depending on ancestry, the physical characteristics of wild swine can vary greatly.Size, shape and color can all fluctuate. And all types of wild swine can raise their hair on the back of their necks, as shown in the right photo, giving them the look of a razorback.