Veterinarian, heel thyself

Today I heard a loud squealing sound from outside. It was horrible. It was a crying dog. Yelping with pain. It was a dog that was just hit by a car. The dog was alive and could walk but ran under the car and growled not letting anyone near him. He was soon taken to the vet but it was freaky. The sound was horrible. He's always been a very grumpy dog and is very territorial.