If a dog
A lot of severe injuries occur by dogs getting hit by vehicles. You will need to try to take the dog away from traffic or if it is walking or running, you might need to try to slow or stop traffic to keep the dog from becoming reinjured by a vehicle. Also, keep in mind an injured animal may bite so take precautions to prevent injury to yourself or others. A towel loosely wrapped around the muzzle, or even a shoestring will help keep the mouth closed.
Spinal and Head Trauma
A dog with a possible spinal injury or head trauma will exhibit the following signs: unconsciousness, different sized pupils, shock, blood in the ear, nose, mouth, or anus, and/or paralysis. If you suspect these types of injuries you will need to find an object with a solid, flat surface (such as plywood, a sled, or a stiff piece of cardboard) that is large enough that the entire animal can comfortably fit.
Pelvic and Leg Injuries
A dog with a fractured pelvis or one which is unable to stand should be transported as with a spinal or head trauma. Be extremely careful when trying to ease your dog onto your transport device as he may be extremely painful and try to bite or escape due to pain.
Safety on the Ride to the Veterinarian
Your dog will need to be restrained in your vehicle once you are able to get him inside. Large dogs should have someone sit near them, to protect them from any sudden turns and to keep them still. Small dogs should be placed in a kennel which is securely fastened in your vehicle. Keeping the animal still at all times is paramount to prevent any further injury, and to keep both you and the dog safe.