Looking for equestrian photography resources

I’ve got a cousin with a quarterhorse and I’m a photographer. Still in experimental stages for subjects and such. She’s been entertaining the idea of me getting some professional pics of her horse.

I also have a school friend who has a horse and does some cosplay, so I’ve been curious about some creative options.

Anyone have some links to their favorite “horse portrait” photographers or maybe some resources for photographers?

I’d really like to keep the horses comfortable as possible.

I hope I flaired this correctly.