I headcanon that in Winkie Country, all royal family members are assigned a Steed to acompany them wherever they go when they leave the castle or attend formal events. It’s indicative of their (in my headcanon) respect and bond with Animals and Horses hold a high position in society and court. They’re assigned to their master/mistress when they are preteen-ish, so Fiyero was assigned Feldspur when he was maybe 12 or 13 and Feldspur was a yearling. The two bonded instantly and the rest is history 😝
I don't know if the movie is even thinking this deep but, hey, everyone, what are our headcanons/theories on who Feldspur is to Fiyero?
My thoughts are that he's probably Fiyero's valet or something similar, and they're genuine friends beyond that.