noun
mad dog; rabid dog
Refers to a dog infected with rabies or, figuratively, a violently uncontrollable person.
狂犬に噛まれたらすぐに病院へ行ってください。
If you are bitten by a rabid dog, go to the hospital immediately.
彼は怒ると狂犬のようになる。
When he gets angry, he becomes like a mad dog.