Viruses are particulate agents of nucleic acid and protein that can infect all living organisms, including animals, plants, humans, bacteria, and archaea. Plant viruses particularly infect plants and spread disease throughout them, causing yield loss. These viruses spread from plant to plant through vectors, which include insects, some fungi, worms, and eukaryotic organisms. The genetic material of plant viruses consists mainly of RNA. The first plant virus discovered was the Tobacco Mosaic Virus (TMV).
Animal viruses, on the other hand, infect animals. Their genetic material consists of either RNA or DNA. Farm animals and pets are susceptible to deadly viral infections if not vaccinated. For example, Canine parvovirus, a virus containing DNA as its genetic material, can cause the death of puppies.