How old should you be to own a gun?
Federal law requires one to be 21 years old to purchase handguns from an FFL (licensed dealer) and 18 for the purchase of long guns. Federal law and most states allow 18 to 21 year olds to purchase handguns from individuals (but not dealers). A few states require all gun sales to be through licensed dealers.
In Texas parents can decide what age their child should be to own a gun as per Texas Penal Code.
It depends. All boys are different. If they have had problems before with being truthful and honest, then you should really consider everything before you buy anything, If your son is a well behaved boy, test him. See how much he wants it. Have him do some research on his own, or, if that is not your style, have him throw in some of his own money. There is no set answer to 'should you…
Your question is rather vague. If you mean what should a physician do if someone OWNS a gun- I would ask why they should do anything. Owning a gun is not an illness, and is a right guaranteed to Americans. About 1/3rd of he households in the US own at least one gun- and I know several doctors that own guns.