Mare kicking and biting stomach?

Hi! So I've recently purchased a mare who has been living outside year round and supposedly has this "iron stomach". She's been at my house for about 7 or 8 days now, and I've noticed that she has this very annoying habit of kicking and biting her stomach all the time. I know, I know, my first thought was colic too, but I don't think that's it. She shows no other symptoms because she isn't rolling or laying down a lot, she has normal gut sounds and a very good appetite. I've very slowly put her out to the full pasture by keeping her in my pasture and letting her graze for a few hours a day and then putting her in a paddock with much less grass and slowly building up her pasture time. There are a lot of bugs and flies out, but when I put fly spray on her it doesn't seem to have much effect. Could this habit be because she is in heat? Bugs are bothering her? Burs are on her stomach? She kicks herself with her front hooves and her back, and she also stretches around to nibble herself on her stomach. Anyone have any ideas of what's bugging her?

Thanks so much!

It could be any number of things. You say the horse has been there for about a week, was a pre-purchase or new arrival exam done by a veterinarian??

Yes, the vet did a pre-purchase exam and she said everything looked fine, even calling her a "diamond in the rough" and a "nice athlete".

If it's bugs, then a simple coating of flyspray should help get rid of them (or at least temporarily)

Has her diet changed since you brought her home? What kind of tests did the vet do on her?

What is her breed, age and current diet?

I'm thinking maybe gastric ulcers?

The grass is a lot longer than her old home, but her old owner said that she's brought her to new places with grass as long as mine, thrown her out there and she's done fine. I'm kind of skeptical about that... maybe it's true! Who knows! I've cut back on her grain a bit because she used to be getting a heaping scoop full. Other than that, no, she's just been living outside and eating grass.
The vet listened to her vitals and her barrel, did some flexibility and strength tests on her legs (she has weak stifles, but those can be improved with hill work), tested her hooves and looked at her gaits.

I was thinking ulcers were a possibility too! Do you know if there are any other symptoms to look for? Or should I call the vet out?

She's a Paint/Thoroughbred cross, turning 7 in a few months and she has a grass diet with free choice hay and salt and she gets a half scoop of grain with Mare Magic in the morning.

Symptoms can include, but are not limited to...

In adult horses, signs of gastric ulcers include:

~ Poor appetite
~ Weight loss and poor body condition
~ Poor hair coat
~ Mild colic
~ Mental dullness or attitude changes
~ Poor performance
~ Lying down more than normal
~ "Cinchiness" - pinning ears and being irritable while tacking up
~ Grinding of the teeth.
~ Belching noises.
~ Slow eating, often walking away without finishing meals all at once.
~ Picky appetite that includes the horse refusing foods or supplements that were consumed readily before.
~ Sensitivity to touch around the horse's lower belly/sternum area.

Horses with ulcers will often do better on fresh grass as opposed to rich hay. (alfalfa)

You can try adding tums to the horse's diet and see that that improved it after the horse ingests them. The Calcium in tums will help neutralize the stomach acid and make them feel better. Maybe try 15-20 tums depending on the size of the horse.

Unfortunately, it might not be ulcer either but I'd talk to your vet and get their opinion. She is obviously uncomfortable. It's just a matter of figuring out what's going on.

My STB mare does the same thing.
IT's just the flies in my case.
I've seen two horses with ulcers, and they didn't do that
I dunno, I hope you figure out what it is!