Not that I know of.
Transport Canada has a regulation regarding transport or carrier security measures; there are some articles in there on cargo that need to be applied by the carriers. The carriers need to abide by those measures, and Transport inspects those measures.
So it's not to say there is nothing being done about cargo, but cargo is not being screened with X-ray equipment right now. That is not to say there is absolutely no security on cargo right now, as the airlines have to abide by the Transport Canada security measures.
Could they be improved? Yes.