mild agression and limp

Question
I have  2 yr old english bulldog..recently he seems to have a limp that comes and goes..he doesn't seem to be in pain..but it is noticeable..2nd question regards recent mild agression..he is a loveble dog..that never has shown any agression..I have made him have a bad habit of getting food fromme when I eat..two times in a row while watching me eat..my kids went to pull him a way and he snapped at them..this has never happened before..last time it hapopened I scolded him and let him know tht what he did was wrong..he seeme dcontrite nd it hasn't happened again..your help onn both questions is greatly appreciated..I am not sure if this matters but both incidents seemed to have started after being treated with steroids after a very bad allergic reaction to possibly some first time served table food.  

Answer
YOu didn't mention if the limp is in the front or the rear. If it comes and goes, chances are he's doing something to cause it, perhaps jumping down from a car, or porch, or even a couch. If it's in the front, maybe he's going down stairs for playing rough. This is something you'll have to watch closely and see if you can figure out what he's doing just before the limp appears.

As for the snapping, that's your fault. Don't even let him near the table from now on. The scolding may have done the trick on that occasion, but do not let him think he can pull this one again.  I doubt the steroids had anything to do with it. Dogs need to earn rewards even for the simplest of things. Random treats are a setup for problems to come.