However, animals can sometimes bear harmful germs that can spread to people and cause illness – these are known as zoonotic diseases or zoonoses. Zoonotic diseases are generated by harmful germs like viruses, bacterial, parasites, and fungi. These germs can cause many different categorize of illnesses in people and animals, ranging from mild to serious illness and even death. Animals can consistently appear healthy even when they are carrying germs that can make people sick, depending on the zoonotic disease.