We all know that a dog with rabies can be dangerous. Even friendly dogs can turn mean. But how does this happen?
There's actually a fascinating piece of biology at work there. Once the rabies virus gets into a dog's bloodstream, it goes directly to the limbic system of the brain. That's where the control center is for aggressive behavior.
It puts the dog into an artificial rage. The virus also incapacitates the nerves used for swallowing, and makes the saliva production go up. That's why rabid dogs foam at the mouth. The rabies viruses now fill up the saliva, and just wait there until the dog bites someone. Bang they've made their way into a new host.
