How to create profile for path that is not closed loop

I have a drawing of the outline of a dog (our Rodesian Ridgeback Koa) great dog.  I first used Inkscape and did a trace bitmap to outline the edges.  Then it suggested grouping the separate edges that were not and shouldn't be connected to make it one group of nodes.  I then imported it and was able to extrude it to give it some shape.
then the fun begins.  Every time I try to combine the segments (node to node) all I get is "not a closed loop"  some are and some are not and shouldn't be.  
I think I am missing some understanding of just how Freecad looks and treats some of these segments.  I like to create drawings and be able to import them into engravable or cut out objects.  I work with a lot of artists who look for this sort of capability.

Would greatly appreciate some insight as to what is going on and what I am not understanding.

Many thanks
Routerworks

Thank you. I used that however when I get to freecad it doesn't want to engrave all the edges that don't form a closed loop. Even if I separate the groups it soems it still doesn't see closed loops as closed.

I'm missing something.

Thanks again

To be honest I had no idea linuxcnc had software that would generate g code. When I started with this a few years ago I have been using Freecad to design different mechanical parts, some of which would be cut out of wood. I just continued with this. Inkscape is commonly used to generate svg files that can be used in Freecad. I also use Blender to create bas-reliefs to do what I think you are talking about. Blendercam also generates surface milling g codes that Freecad has some difficulty with.

Not to get too long winded, I simply want to be able to draw something in Inkscape, some closed loop and some curved lines that are not connected beginning to end, export it as a svg, import it into something and generate a g code.

I should probably look to the Freecad community for the answer to this. I will definitely look into what CAD CAM capabilities are available from linuxcnc.

Thanks for all you help

Thanks a lot. Been using the same old things for too long. I'll have to look into this.
Thanks again

For what it is worth, I have been working with Inkscape and find it is excellent for creating engraving paths and generating g code. Much easier than using Freecad. However Blender still seems the best for bas reliefs and generating their g code. Freecad has is best for CAD drawings and generating milling g code. Image2gcode may be on option however I use a windows computer for developing my g code and linuxcnc strictly for operating my router.

Your seggestion of using inkscape for carvings or engraving makes life much much easier than the other routes. These softwares seem to be the big three for coverng 2D to 3D g code with free software.
Thanks again for your advise as it is saving me tons of time generating engraving paths from curved drawings or text.

Thanks again

Interesting conversion synching to an analog signal have never done that. Very nice build. I've attached a picture of my monster build 4' x 4' 6 inch Z.