Is my horse sick? :(

My mare Annie was laying out in the pasture this morning when I went to feed, she got up and came to the barn and got in her stall and took maybe two bites of her grain. I ended up leaving her in her stall instead of letting her out with the other horses. I came in and an hour later I went out there to check on her. She was now laying down in her stall and still hadn't touched her grain, or water. I got her up and walked her around a little outside the barn and she tried laying down out there. I took her back into her stall and as soon as she got in there she layed back down.
She isn't rolling, or biting at her stomach and her breathing seems fine.
Could it be the heat? Its about 100 degrees outside today here and has been like this all week.

I won't be able to get the vet to come out until wednesday if I needed one.

I will continue to keep checking on her every 30 minutes to an hour. But I can stay out there with her if I need to.

Is she dehydrated? Pinch her skin and see if it stays up a little while, in this heat I would be worried about that. If I were in your shoes I would get a vet, if your vet doesn't come call and call until you find one that will. Anytime a horse doesn't eat is a cause for concern, because their systems are designed for constant grazing, so they are normally hungry all the time.

Is she drinking? Is there fresh poop in the pen? Check for these things, but I still would get the vet out sooner rather than later. If my horses aren't eating, it's major. They never turned down food.

She isn't dehydrated and yes there is fresh poop in her stall. I wet her grain a little and she ate a little out of my hand. She has never turned down food before, I will try getting the vet out sooner, but it would probably be tomorrow.

And she isn't drinking either.

Wetting the food is a good idea. Make sure you tell the vet she isn't drinking.

A horse in 100 degree heat that isn't drinking sends off warning signs for me. She may not be dehydrated yet, but if she doesn't drink, she will be.

How is she this morning?...

She may be in heat stress. They will lie down because the ground and stall floor are cooler. If it were my horse I'd be hosing it down. I have a large fan blowing in the barn and the two horses stand so it blows on them. I have been known to flood an area with little grass in which the horses love to roll. It not only cools them but the soupy mud offers protection from the bugs.

As Saddlebag said cold hose her in case it is heat stress. It can't harm her and if it helps her feel a bit better it is a good thing.

How is Annie this afternoon?