First suggestion is to check her out medically. Make sure you get a full blood panel to see if anything is out of the ordinary and ask your vet if he can evaluate her back and legs. Many arthritic dogs act the way that Nala is acting. Be sure to tell your vet Nala is starting to show some discomfort at being grabbed and you feel it may be medically related. This will give your vet a heads-up as to what to look for.

Second suggestion is to desensitize her to touch. Rather than grabbing her and forcing her out, try gentler persuasive methods like enticing her by throwing a treat outside, or clipping a leash onto her collar instead. Also, to desensitize her to touch, you want to associate touching her with good things. A general plan would be to poke her lightly, give a treat if she doesn't react, prod her a little, treat again, pat her, treat, grab a little fur, treat, etc.