I just bought back a mare that I sold in March 2017. The new owner (a young girl) ended up riding once after I sold her, then lost interest and let the mare sit in her pasture. She was ridden maybe 4 times by the neighbor kid since March 2017. 

She's a great body weight, super healthy looking. I had her teeth done, she's been dewormed, and her feet were trimmed (but they still need some work). I've ridden her twice, just light walk/trot stuff. What would your regimen be to bring this mare out of her "retirement" and back into working shape?

ETA: She was a solid 4D horse, and had really bad ulcers when I sold her the first time. She's now 12, no reaction when pressure is put on her ulcer points now.

I'm in the same boat. Bought a 17yo blown up horse thats been ran maybe 2-3x a year since 2014. He has been a pasture pet and he still had ongoing ulcers when I bought him, he was sitting for quite a few months. I put a treatment dose of Zesterra through him ($125 for the big treatment dose bottle) and then I just started slow. He was in a pasture, so he was in pretty decent shape compared to one being stuck in a stall. So with a pasture horse coming from a pasture pet, I always keep in mind it takes about 8 weeks to fully 'condition' a horse that's been off a few months. I give 10-11 weeks for one that's sat for longer than say winter (4ish months). I start with walk/trot for a week or two, then add in loping and some hills circles serpentines etc. Then I add some interval sprints about about 6ish weeks and really start riding them hard on hills, etc. Then at about 9 weeks I'll reintroduce the pattern and go from there, starting at walk and trot. I will haul them in the meantime if I'm going and just make them camp out in the alley or the trailer, just makes the race environment not 'awful' restarting them into it again :)

I agree, just slow and steady for a few weeks then reintroducing the pattern and heavier work and see how it goes. I'd rather have them tip top shape trotting the pattern than blowing and going after one high lope through. Eye roll, see it waay too often. 

Thanks, this was really helpful!

Won't be getting a new truck til the end of the year anyway, so I'm not in a rush to go back to races this summer or fall. I'll spread out her workload.