Definition & Bedeutung von "foam at the mouth"

What is the origin of the idiom "foam at the mouth" and when to use it?

The phrase "foam at the mouth" has its origins in the physical symptom associated with rabies, a viral disease that affects mammals. When an animal such as a dog contracts rabies, the virus affects the central nervous system, leading to erratic behavior. This idiom is commonly used in discussions of heated arguments, intense confrontations, or instances of extreme frustration.