A pack of dogs? Do you live where there are wild dogs? If so, then trying to capture it to take it to get treatment could be potentially dangerous. Dont get me wrong, it was awful that this happened and you did try to catch it, but if it was wild theres a chance that the dog in question could have had diseases like rabies. In that kind of situation its definitely better to call local animal welfare or animal control to come and check it out as they have the equipment to check on a wild animal. If it was a pet then well, I just hope that its found and sees a vet soon.