Hello, We have a Belgian Draft horse that keeps growing, so we went with the

Featherlite Big Horse Trailer, model 8549, (3 horse gooseneck) it has the 50 inch wide stalls, 7 1/2 interior height, and 8 ft wide,  and extra  tall front stall escape door, and now our draft has the perfect amount of room.  After a lot of research,  I found that most trailer manufacturers would make the stalls this wide, it just had to be a custom order trailer, whereas the Featherlite dealer in my area, has them in stock.  Just because a trailer salesman tells you your horse will fit, it's the "biggest they make", be wary...until they know it's a draft horse, they all wanna sell you their big trailer.

We absolutely love our Model 8549. Good Luck.

make sure it's 7"6" or taller, check the length of the stall as that will vary quite a bit besides the width.  The higher quality trailers tend to make larger & longer stalls, hence the higher price tag besides the quality.

I have a 4 year Percheron Mare near 17h and 1500lbs(she uses and 87" balnket) and the other horse is a 16.2h NSH: we got a 4h BP Circle J Lighting Deluxe and basically made it into a very big 2horse slant stall (7'4" H and 6'6" works fine since the perch has a short neck). Occasionally, for short trip, we can put the NSH and our third horse (a littel shy of 16h) int he last two slant slots.

i would recomend getting a 5 horse if you are going to move 4 horse. Othereise since i assume the donkey is relatively small you could load the draft and the donkey next to each other(in different stalls) and maybe enlarge the draft horse slant while making the donkey's smaller by redrilling the side of the trailer and moutning the divider further back/fwd depending on you loading configuration