Wry neck (torticolis) is a common neurological symptom when there is a neck or head injury. Separate him so he doesn’t get picked on close to food and water, and feed him both every 2 hours. Sugar water 1 tsp per cup or electrolytes would be good while he is in shock. I would get some human vitamin E softgels 400 IU and give 1 orally daily, along with human vitamin B complex which includes all b vitamins, and give him 1/2 tablet daily. Let us know how he gets along.