Wind sucking

Question
We were recently given a paint gelding and Appaloosa mare. We don't know much about their pasts other than they were given to a friend of ours when their owner lost his job and was unable to care for them. We were told the horses have been together for three years and we know our friend had them for the past year. The horses are supposed to be around 10 to 12 years old. We've had the horses for three weeks and are noticing some issues. The gelding wind sucks a lot when ever we put him in the stall. We only put him up to feed and groom and then both horses have free range of 20 acres of nice grassy pasture. Other than this he's very calm and relaxed. I don't notice him doing this except in the stall. I've read about cribbing collars but want to know if you have any recommendations. He does not eat wood he just suck air. Is this harmful to him?  His weight is on the low side and I'm wondering if this could be a contributor. Also can this damage his teeth?  His two middle front top teeth are very worn down or broken looking. He eats grain and hay fine and seems to graze ok

Answer
We have horses that do this from time to time, and have worked with TB's and one of those mares had no teeth left due to this.  

Some feel it is major deal, others don't.  Usually a collar works best, to me at least, if horse is stalled more than less, as too much chance of getting something caught in it in the pasture.  For that reason alone I would just let him be.

It might be a good idea though to have vet do dental work on both of them, due to age, and not being sure if they have had teeth floated lately.  And worming would help, especially if vet does fecal count, to see what worms are present.

He could have hooks that are making it harder for him to digest his food too, and also might need more feed/hay to get weight back up to where it should be.  Vet can also tell you age of horses, or should be able to.

I would not worry about the windsucking at this point.  There is a school of thought that it is a form of equine OCD and something they almost get addicted to?  Releases endorphins, or something like that, and may just be a habit horse has fallen into.  

Being in a stall might make him more prone to do this, as he is anticipating feeding, but I would just let it be for time being, and enjoy both of them.