Sources of biological hazards include bacteria, viruses, insects, plants, birds, animals, and humans. These sources can cause a variety of health effects ranging from skin irritation and allergies to infections (e.g., tuberculosis, AIDS), cancer and so on.
If you started searching in the directory for the cause of a disease or injury, you would probably end up in the "Biological Hazards" section first. On the other hand, if you searched for the disease itself, the search engine would take you to the "Diseases, Disorders and Injuries" section.
This section will include information on animal bites, since they can cause certain infections or diseases. However, this section does not include information on the harm or injuries caused by the physical action of animals. For example, kicks from horses would be discussed in the "safety" section [not there yet].