It depends on how fast you act in getting the dog treatment after he gets injured. Did a vet tell you that your Chi has a concussion, or are you assuming that your Chi has a concussion. Chihuahuas are very tiny dogs and it doesn't take much to injure them. If they get hit in the head, the blow can kill them. When it comes to head injuries, you need to ask fast, because major damage and possible death can occur, if you don't get your dog to a vet FAST! When did this happen to your Chihuahua and what happened that you think he or she has a concussion? How is he or she acting? If you have not already taken your Chi to the vet for this, then please get off the computer and take him or her to an Emergency Vet Now! They are open 24/7 and your Chihuahua really needs to be seen. I really hope that everything turns out ok!
Yes, but it needs to go to a vet, and its according to how bad the concussion is.