Age to aquire a service dog?

All I know is, "soldiers" are in the army; servicemen/women are in any branch of the military.

I think it's kind of disrespectful because it implies that well. The EX part is usually something negative attached to something else. EX wife, EX smoker, EX boyfriend, etc.

None of those things are positively viewed, and veteran is more respectful of the people who have served their country. At least, that's my opinion.

This. Exactly.

Maybe this puts it in perspective. When you say "ex-soldier" you are lumping in those that have been dishonorably discharged with those who have faithfully served our country. Former-soldier is much more respectable in general, and veteran should be reserved for those who have served honorably.

So basically, Joe Schmoe that served in the military and was kicked out for bad behavior or drug use fits the "ex-soldier" name, whereas say, my ex-husband who is an OIF/OEF veteran it would be derrogatory to call him an "ex soldier" when he retires, because obviously those two people are a class apart in their actions and honor and duty.

quick break-down for Lizzy

Soldier = Army
Airman - Air Force
Seaman - Navy
Marine/Corpsman - Marines
Guardsman - National Guard
Reservist - a reserve service member of any branch.

The proper term is "service member" if you don't know the branch, so you're good there.