What is disease? A disease is a disturbance in the normal structure or function of an organism, group of organisms or the entire body. Diseases affect different organisms in different ways, they may be temporary, they may be chronic, or they may be terminal. They may even be localized or widespread through an entire body. Many diseases have been eradicated, but, some have no cure. Humans and other vertebrates have a system of specific immunity to combat disease. Some disease causing organisms invade body tissues and then destroy them, while others setup a symbiotic relationship with the cells. Most communicable...
plants. They live in and cause damage to the roots, stems, leaves, and bulbs of plants. Non parasitic diseases are attributed to weather conditions.

What are some disease causing organisms that affect animals? These diseases are of great importance to humans, they could affect animals that are used for, or produce food. Some of these diseases may even be transmitted to humans. Many microorganisms exist peacefully inside animals, some of the symbiots are even benificial to the animals that they live inside. Other microorganisms, pathogens, cause disease in animals. These pathogens include bacteria, viruses, fungi, prions, and other parasites.