So my horse Gunner has recently lost a lot of weight so we de-wormed him, did fecal egg count etc, nothing. So we uped his feed, he is getting 6+ pounds a mean almost 15 pounds a day of sweet feed (with beet pulp), rice bran, and horse manna to try and make him less skin and bones, so far he hasn't put much weight on, did i mention he is also getting fed alfalfa hay and orchard grass? He has ulcer but is treated for those twice a day so 🤷‍♀️, yesterday his right front leg swelled up with out and signs of injury or heat. is was so swelled you couldn't see the splint bones on the side of the leg yet he wasn't lame. Today we investigated it more, found he had rain rot on that leg, hoof to knee, but we still don't know what caused the swelling, we have be washing/scrubing his leg to help the rain rot but not much we can do. I need to make up my mind with him because I have a competition on the 24th and need to know whether i need to pull out or take a different horse, sigh, its been a heck of a week.

I would definitely be bringing a different horse to the show. Yours doesn't sound ready at all.

Has he maybe been tested for an infection or possibly lyme? That might explain the weird weight loss/swelling. I'd also test for sand, even though you said it's not likely in your area, it's still worth looking into.

Im considering it though, this morning swelling was significantly lower, im starting to see splint bones again.

I would count on your horse being out for the show. Your horse is a reflection of you, and even if you are putting a ton of feed into him, others might just see an underweight horse.

Hopefully he gets better soon!

If he's being fed that much and isn't gaining weight, I'd consult a vet. There's something else going on.