The answer is both yes & no, depending on the severity of the galls. If
it is chaffing or minor irritation, it should heal well. Further
galling should be prevented by choosing different tack, tack
positioning, etc.
If galls become sores that form scar tissue, the scars are more prone to
reinjury. There aren't usually nerves in scar tissue & it is often
poorly supplied with blood. Few nerves = more damage before the horse
notices to complain. Less blood supply = slower healing.
Girth irritation can be a problem. I use a neoprene girth by OF, set
the saddle slightly back, stretch the legs out before riding, and keep
the girth & horse clean in that area. I <still> get occasional
irritation at longer distances. My husband has a saddle (Hook
endurance) which has a "V" rigging that he moves to a center fire
position and uses a mohair string girth. He's yet to ever have a girth
sore but the same rig rubs Rocket raw.
You'll have to experiment with what works for you. What works for my
gelding didn't work for the mare & irritates my husband's gelding.
Linda Flemmer
Blue WOlf Ranch
Bruceton Mills, WV