Part II. Modes of Introduction of Exotic Diseases of Animals
Now that you have reviewed the introductory material, we are going to investigate actual modes of introduction of exotic diseases of animals. Diseases are introduced in one of two ways: unintentionally or intentionally.

Unintentional Introduction of Exotic Diseases of Animals
Unintentional or accidental introduction occurs when disease agents are brought to new areas via the movement of fomites, vectors, infected animals, animal products, or by the emergence of new diseases or new variants. The likelihood of these introduction events can be decreased through strict surveillance, precautionary practices, and improved biosecurity. In order to enhance your understanding of modes of accidental introduction, we will present examples of each of these potential routes for you to review. As you work through the examples you may wish to review the definitions and examples presented in the first half of this module or explore the expanded information on specific diseases provided in the outline section.

Intentional Introduction of exotic diseases of animals
Bioterrorism, or biological warfare, is defined as the intentional use of microorganisms or toxins derived from living organisms or viruses to cause death or disease in humans, other animals, or plants in civilian settings. Bioterrorism can occur by any of the previously described routes: fomites, vectors, infected animals, animal products, or emerging diseases.  In veterinary medicine, we are also concerned about agroterrorism, which is a specific form of bioterrorism in which the biological weapons target animal or crop agriculture to cause economic damage and instability.