Never Trust a Pig

From the Wiki article:

Pigs are omnivores, which means that they consume both plants and small animals. Pigs will scavenge and have been known to eat any kind of food, including dead insects, worms, tree bark, rotting carcasses, excreta (including their own), garbage, and other pigs. In the wild, they are foraging animals, primarily eating leaves and grasses, roots, fruits and flowers. Occasionally, in captivity, pigs may eat their own young, often if they become severely stressed....

Pigs harbour a unique (when compared to other domestic animals) range of parasites and diseases that can be easily transmitted to humans. These include trichinosis, cysticercosis, and brucellosis. Very commonly, pigs are also known to host large concentrations of parasitic ascarid worms in their digestive tract. The presence of these diseases and parasites is one of the main reasons why pork meat should always be well cooked or cured before eating. Some religious groups that consider pork unclean refer to these issues as support for their views.

Pigs are extremely susceptible to pneumonia, usually caused by weather. Pigs have small lungs in relation to body size; for this reason, bronchitis or pneumonia can kill a pig quickly.

Pigs can be aggressive and pig-induced injuries are relatively common in areas where pigs are reared or where they form part of the wild or feral fauna.

Domestic pigs are often inbred, leading to the expression of recessive traits. Congenital malformations are common. One such malformation is the duplication of a pig's head.