little black biteing bugs HELP!

[westparc]

every year my mare gets bitten on her belly button and inside of her legs which make her swolen raw by little black bugs.
i have tryed different fly sprays and creams but i find this can burn her skin what can i use to stop them help please!

 

[sunshine19]

My Section D has sensitive skin and use to get eaten alive by biting bugs. I use a light coating of vaseline on his sheath and bellybutton. It creates a great defense barrier and lasts for up to 24 hours.

 

[Echo Bravo]

Get her a Boett rug, expensive to begin with but pays it's way and it sound like sweet itch