Because I'm a veteran, I usually come up with oddball support characters in T2K and let everyone else play the Rangers and Special Forces types.
One of my favorite concepts is a veterinary assistant /nurse who gets drafted. He's not much of a doctor, but he's all the doctor you got!
When I served in the US Army, there was a major push on to eliminate drug use and alcoholism in the barracks, along with all sorts of other crime. This was in the early '80s when the Army started getting a handle on itself after the Hollow Army of the 70s. After Vietnam and the shift to an all-volunteer force, the Army was just a shell of itself. There was a lot of coke and hashish on bases, a lot of our NCOs were 'Nam veterans and professional drunks... they were alright 26 days out of the month, but the two days after payday they were nowhere to be seen, drinking their pay. I joined just as this was being dealt with. So I saw a lot of the MP drug dogs.
But other all services used security dogs and there were quite a few bomb dogs... though not nearly as many as nowadays.