[Olefin]

The history re-enactors is probably exactly where you would get a lot of the cavalry units that MilGov and CivGov would be raising. There is an article in Challenge Magazine number 42 that has exactly that as the basis for a cav unit

"1st Cavalry Squadron, NJSM: Seventy-five horsemounted troopers armed with FN-FALs, four M79s, and two M60s. They also carry a miscellaneous collection of sabers looted from a local museum. This unit was initially formed around a cadre of a half-dozen civil war reenactment enthusiasts, and some of the troopers use their reenactment uniforms and equipment. "

Sounds like what you have is a unit that had some horses initially in it that were accustomed to the sounds of gunfire as part of the re-enactment and the re-enactors helped train the other horses afterward.

By the way its not just gunfire that makes horses skittish. Ever seen the Braveheart scene where Gibson is giving his freedom speech before the Battle of Stirling? If you notice every time he yells the horse gets skittish and starts moving. Him moving back and forth as he made the speech wasnt written into the movie, it was the horse reacting to the yelling.

By the way that canon article (A Rock in Troubled Waters) shows that horses are definitely still available in 2001 and that they are being bred for government use - from the article

"Port Elizabeth: The 150 people inhabiting Port Elizabeth make their living raising and selling horses. They live in a cluster of buildings near Route 47." and
"The survivors are relatively prosperous by Twilight: 2000 standards-they farm enough to eat well and even export a bit.
Dietary protein comes from fish and chicken. Goats, sheep,cattle and horses are raised primarily for government consumption.
Salvage and re-manufacturing are thriving cottage industries, and pay the taxes in the Milgov protected areas."