Definition for Zoonosis
From Biology Forums Dictionary
1. An infectious disease in animals that can be transmitted to people. The natural reservoir for the infectious agent is a animal.
Examples of zoonoses include rabies (a viral disease that can be transmitted to humans through an infected animal's bite) and psittacosis (a chlamydial infection resembling influenza that is spread to humans by the droppings of infected birds).
Anthrax is a zoonosis. It normally affects animals, especially ruminants (such as goats, cattle, sheep, and horses), but can be transmitted to humans by contact with infected animals or their products or by biological warfare.
2. Diseases that are naturally transmissible from animals to humans and from humans to animals.