Rabies is a viral disease spread through animal bites, usually via saliva. It affects both wild and domestic animals. People can contract rabies through bites or scratches from infected animals. There are two forms - furious rabies causes hyperactivity and agitation, while paralytic rabies slowly causes paralysis. Initial symptoms are flu-like. Rabies is diagnosed through tests on blood or tissues. Untreated rabies is fatal in humans. Prevention involves vaccinating animals and prompt treatment of bites.