Alright so yesterday I stupidly spooked my 9 mo old colt and he is a very good jumper to say the least and he ran and jumped the fence over into the neighbors pasture but he didnt clear it and gashed his chest on the fence post. What should I do about it? Leave it alone? I also read that it is helpful to spray a solution of salt and water on it daily.

"gashed" is by whose definition

To me that word indicates stitches might be required; therefore a tetanus shot and some antibiotics and that all means a vet should examine him.

If it' a pretty bad opening but looks like it will heal without stitches (or scarring/proudflesh), I would still want him to have a tetanus shot. That still means a vet and the vet could then suggest the best topicals to apply that will help heal yet won't burn the open flesh

Hi: Please clean the wound with a mixture of 1 tablespoon table salt to 1 gallon warm water (saline solution). This solution is PH balanced and is similar to that of the horse's own body thus it will not burn or sting. After cleansing the wound a dusting with Wonder Dust would help protect it and aid in healing. Because your horse is young have someone hold him while u work. The wound will heal slowly and as it progresses remember to prevent scaring by applying vitamin E. Good Luck

Thats not too bad of a gash I would clean it out with bedadine (iodine) and put furazone on it if its isnt too bad. I'm not a vet, this is just my opinion if it were my horse!