Yes -
My 20 yr old mare last year chocked soon after foaling. I usually don't feed my mares that foal grain for at least several hours after foaling, well she foaled at 3pm and feeding was at 4 usually, so she was nickering and I gave just a Handful litterally..............she was excitiing and next I knew nastly slime coming out of her nose and coughing ext........
I at first tried to flush the mouth with water from a 60cc syringe, with really no progression - of course she had already had some banamine after foaling, but in a few hours gave her another shot of it. During this time I was also massaging the neck to - thinking I might could break it up. She wasn't in dire stress, choking looks horrible, slime dripping down from the mouth and even out the nose, and you can tell when they cough they are trying to cough something up.
With horses the airway is not blocked when choking, so I watched her for a while, (on camera at the house and up with her both) she seemed to be progressing.........but then not really, so I ended up loading her up in the trailer over to my vets late late that night. Sedated her mildy, passed the tube down and it just so happened she tried to gag and let the tube pass very easily to where it needed to be - she passed the lodge of stuff and was fine. The problem with chocking is they can aspirate and cause pnemonia if let untreated too long.
Now she was SORE for a while..........I even soaked her Equine Sr. (which she didn't like) and soaked alfafa processed and beet pulp. She didn't eat "good" for a while..........but I think once the soreness got over with she started back fine and dandy. She also had a sort of "rattle" to her in breathing/coughing ext......just from all the fluid for a while.
All that said she is wonderful now - and is due to foal May of this year. She hasn't had any choking experiences so to speak, she of course due to her age is on lots of Equine Sr - so I am not sure just how much hay she really eats (she has a round bale out 24/7).
There were two times, this winter, when I went up to the barn LATE, and she was down eating hay with the other mares, and instead of running up to me like normal she just stood there and was staggering when trying to walk, almost like drunk. I had to push her up to the barn to check on her, put in a stall, no eating of feed ext.......yet no colic signs, but I still gave Banamine to her, she was passing poop ext. I put her under camera both times and by next morning it was if nothing had happened.
The second time this happened I called my vet and he said she probably got excitied or startled down at the hay bale and in the excitied almost "mimicked" her choking, thinking herself that she might have - that several horses that have chocked do that too.
But she is a fat, healthy, happy, 21 year old mare who is big as a barrel and a wonderful mother.