I am so soft hearted toward animals; will this movie upset me

There are some upsetting parts.

The accident at the beginning which drives the entire story. It is done tastefully and does not sensationalize the situation.

There is a minor part at the end where the horse is hobbled, but all ends well.

I think the movie is worth some temporary and fleeting discomfort.

BTW I don't watch movies where the dog dies, if that helps.