I don’t remember much else about this movie, saw this scene when my parents were watching it several years ago. Probably late 90s very early 2000s, in color, and English.

The horse was sliced in half from front to back down the spine basically, and set up like a lab slide, in a huge white room. There was a bunch of other things set up like that I believe but I only really remember the horse. There was a woman in the room but I can’t remember what she looked like, thanks!