I don't think you'll find a similar program for OS X. A .dwg file is a CAD drawing file. As I said there are some utilities that may read the file, but I doubt there's anything like the Window's application.
You cannot run Window's applications on a Mac unless you use virtualization software such as
Parallels Desktop for Mac or
VM Fusion. You can also dual-boot an Intel Mac using OS X or Windows by using the Boot Camp software (Utilities folder.) You need a legal copy of Windows XP with Service Pak 2.