It's normal to question your horsekeeping chops at a time like this, but as many others have pointed out, there's no foolproof way to prevent injuries. Accidents happen even in the most perfect of pastures. And stalling is no guarantee, either. I'm sure I'm not the only one with a story about a horse they once knew that broke its leg in a stall.
Most anyone would agree that quality of life trumps length of life every time.
Dreadful Acres: the chronicle of my extraordinary unsuitability to country life
I am so sorry that you had to go through this. You did absolutely nothing wrong. You were providing the best life you could for your mare. Who knows, maybe this was actually an easier way for her to go than what may had been in store for her if she died of her medical issues. I think of that when I think of my mother who died from injuries sustained in an auto accident when she was in the last stage of Alzheimers disease.
It is true that these horrible accidents happen regardless of how carefully we look after our horses. In 2010, Blue Hors Matine died when she broke her leg in a freak paddock accident. I can't imagine that there was a horse anywhere who was being more carefully cared for. She had retired from a spectacularly successful dressage career and was in foal with her first foal. I'm sure that nothing was left to chance in her care, yet the unthinkable happened. Think of what you gave your mare and what the two of you shared. She was a lucky girl.
"The captive bolt is not a proper tool for slaughter of equids they regain consciousness 30 seconds after being struck fully aware they are being vivisected." Dr Friedlander DVM & frmr Chief USDA Insp
I'm so very sorry... And yes, please do NOT feel guilty. You did nothing wrong, and accidents can happen anywhere, anytime. My horses live outside together, too. They're all teenaged and older, and it's better for them to be able to move around 24/7 and be able to run and play, roll, sleep, walk around, etc. Just owning these wonderful animals is a risk we're willing to take for what we get back from them in return. Sorry again for your loss!
My heart aches for you. I lost my 22 year old heart horse to a pasture accident last night. I found him with a broken shoulder. My heart is broken and I can't breathe. I feel guilty, angry. I understand. Big hugs to you.
So sorry. My guy moved to pasture board this year, and is exceedingly much happier. You do what you think is best for them, and without a crystal ball, you can never know what will happen day to day. Am sure she appreciated your care.
Being right half the time beats being half-right all the time. Malcolm Forbes