I thought you was unable to carry a gun in a semi?I begged my husband for over a year to get dog and he said the thing you did,The 1st mistake was getting out and checking it.After begging him he did get a dog.My thought made is wrong.But i think if there going to try and jack your truck and there is a dog in there one.either going to shoot the dog and alert people or two the dog being mean enough will make them wish they chose another truck.And please understand i dont think a dog is less then human,just that it will make them think.Now my husband rides around with a boxer in his truck that he cant live without.Tried to get him to take are Mojo lol 150 Great Dane Puppy,but shoot last time he was home,we was playing around and he grab my head and she tried to bite him lol