Slant Load Downside:
1.  Regular slant load stalls (48" offset, 40-42" width on wall) are not great for larger horses (anything over 16). 
2.  The conventional rear tack often provides limited space for the horse
3.  The conventional rear tack limits space for person loading horse, is a safety hazard

Check out the 3H Slant Gooseneck Safetack Trailer for an alternative to the conventional rear tack

Slant load Upside: 
1.  For hauling 3 horses, slant load trailers are shorter and use the space more efficiently vs a 2+1. 
2.  Slant load Living Quarter layouts use the space better (corner shower fits nicely in slant corner).
3.  Because of smaller horse trailer, you can use smaller tow vehicle

If it were me, and my tow vehicle (and wallet) could handle it, I would go with a gooseneck (2H or 3H) slant.  For a smaller tow vehicle and 2 horses, go with straight load bumperpull.  Anything with living quarters, go with a slant.....just my $0.02.

Bartley Heath
Bartley@DoubleDTrailers.com
Buy Factory Direct and $ave at DoubleDTrailers.com

Bart covered it pretty well.  Most straight load trailers will be 7'6" tall, and most of them will have an escape door on both the left and right side at the front of the stalls.  It is definitely a safer trailer for YOU. 

 For the horses safety though, I would choose the slant load.  When you think about it; in a sudden swerve situation, the horse(s) in a straight load will get thrown left to right pretty violently.  However, in the slant load in a swerve situation, that horse more or less rocks with the swerve.  If you are ever in a head on collision (God forbid); the straight load horses are going forward into the dress wall or front of the trailer; whereas the slant load horses body will push against the dividers or the slant wall. 

We had a customer that was in a headon with a horse in a 3H slant load in the first stall.  The truck and trailer were totaled, but the driver and the horse came out of it pretty much unscathed, due to the trailer being a slant load and the driver wearing a seat belt.  I'm not so sure the horse would have been so fortunate, had he been in a straight load trailer.

I went through the same triage earlier this year deciding what to get for my first trailer.

much of it depends on YOU. what does your trailer HAVE to have? and what limitations do you have re: towing power, horse size and loading ability, what do you use your trailer for?

I got to get hauled around in a friends straight load Gooseneck for a full year and it was very nice. worked great. we'd open the escape doors and tie the horses up on the side and they could munch out of the manger happily, AND see their buddy on the other side :). Even my old arthritic guy hauled just fine in the straight, tho after a super long ride the backing out to unload could be rather hard, even with the ramp. It was a very efficient use of space and all the surfaces (front, back, side) were padded so as the trailer moved about, the horses could lean comfortably.

that said, I ended up with a 2 horse slant load gooseneck. Even with a bigger dressing room, my net length is about the same as my friends straight load. I like that I can unload my old guy by backing him out OR by letting him turn around (we do both, just so that if we HAVE to do one, it wont be the first time :)). I do miss the "hi buddy!" see through of the straight load but sometimes ponies have to deal ;). I did spend extra for jail bar dividers so that my guy could see his buddy in the trailer but not be in the buddies face the whole trip (which made for VERY cranky buddy when they offloaded ;))

I will say that I am NOT a fan of the rear tack for all the safety reasons mentioned above and so chose my trailer specificially to NOT have one. I like that my horse has NOTHING in the horse compartment but horses, and that I can open the double doors WIDE for loading and unloading. Not all slant loads have rear tacks, so it wasnt too hard to find what I wanted.

short story? IMO for what I wanted, either straight or slant would have worked. I just ended up with a slant load cuz thats what had all the other features I wanted. I'm told that some horses wont do a straight load, but I'm also told that some horses wont do a slant. so again, its all about what YOU need and want :)

good luck!

Here's an aluminum slant load Exiss that wrecked. Both horses survived

http://www.myfox8.com/news/wghp-photos-biz-85-accident-090828,0,369045.photogallery.

My two horses scrambled less in the slant load.  Same two horses, when we got the slant load, I was able to discard the leg wraps.  Without the leg wraps in the straight load, there would be hoof & leg injuries from stepping on each other.

Your horses may be different...

For our long distance hauling, we use a 6 horse head to head.... You can get to each horses head to swap hay bags, feed, water, etc, walk any one of them off the trailer in any order. Walk them out and down the side ramp. May take a little more truck, because the trailer it a bit longer than a slant 6 horse. Our run around is a 2 horse straight load with a side unload, walk them in the rear and out the front... I call it our half a' head to head...  The three horse slant sits in the barn loaded with hay.... Nothing wrong with the slant load, it's just that the straight load trailers work better for our operation.

Horses seem less stressed when they've been riding backwards.... Maybe it's just seems that way, no scientific data.....

I had a 2H straight load with a dressing room, and now have a 3H slant with DR and rear tack. We haul two horses and both trailers are BP.  Our trips are usually 3-6 hours mostly flat to rolling, interstate and state highways with secondary roads in there too. My horses are good travelers and don't have problems with loading and unloading.

Both trailers are good towing, not a problem ever.

The straight load had escape doors in both stalls, and that made loading and access easy. Unloading wasn't bad, except sometimes they'd be kind of hesitant to back/step down, and that put some wear and tear on the lip. Also, the walls and divider showed that the guys did some scrambling in there sometimes. One time I had a horse freak in that trailer, he went down, and getting him unstuck and back up was quite a job.

I have no problems loading them in the slant, having the last stall empty. I've hauled a third horse a couple of times, and had to think ahead of who needed to come out first. If the 3rd horse doesn't like to back out, there are issues because of the wall of the rear tack.  With just two loaded, they turn around and walk out no problem, and one is pushing 16 hands. There is an escape door in the first stall, but I'd be reluctant to open it with a horse in the stall -  the little retaining strap will do nothing to restrain a would-be escapee and he'd surely get stuck in the doorway. As for hauling, I have only a few slight scuff marks on the lower wall of the butt side, and the dividers get a little smudgy so I know there's some leaning or rubbing going on.

I love the rear tack because it keeps the stinky horse stuff out of my dressing room. Having a spare stall gives me a ton of room for hay and other stuff. Up til now, the 'junk' needs to go in last and be unloaded first, but with careful packing, it's fast and easy. However, this year we have a big water tank we'll fill, so we'll try putting all the hay, water, pans, buckets, and some of the camping stuff in the first stall and move the horses back. If the trailer hauls well and tracks w/o sway, we'll stick with that plan because it'll be much more convenient.

Despite the inconveniences I prefer the slant because the horses seem more comfortable in it and I really like having somewhere to stow the smelly poop bucket, sweaty pads, etc away from my little area.

Here you go, get the gooseneck trailer and one of these.... http://www.mrtrailer.com/safetyhitch.htm  and you'll be able to pull it with almost anything.... Stopping it may be difficuklt with some smaller, lighter vehicles.!!!

http://safetyhitch.com/index.html

wow, what great engineering!

are those legal in places where you're not allowed to hitch a trailer to a trailer?

and how are they for backing up? does the trailer move like a bumper pull or gooseneck when in reverse?

 The late Dr. Rooney ( noted vet and equine pathologist) had an opinion on the matter. http://www.horseshoes.com/farrierssites/sites/rooney/trailering/tra...

Personally I've had both and can't tell the difference. 5+ hour trips in both and had to slam the brakes in both. Everyone stayed upright. Then again my horses will load and travel in a beer can if I tell them too.....

on larger horses in slant loads...depends on the trailer.

my friends with drafts haul in a warmblood sized Featherlight slant load no problemo. Their truck tops out on poundage before the trailer is physicially full :)

even my standard sized TrailsWest fits my friends giant fat thoroughbred just fine in the second stall.

measure the stall size INSIDE the trailer, and the stall height INSIDE the trailer, take into account mangers and wheel wells, etc and measure your pony. with careful shopping, you should be able to find one that works for you just fine :)

on the article on vector forces inside a horse trailer...

wow. that made my little scientist heart go all pitterpatt!

thanks for sharing that :)

now, do I get bonus points for using the word "yaw" today in a sentance? :)

If the trailer and horses are yawing while you're towing, you will be in dangerous territory. Yaw, pitch and roll are the three terms commonly used with aircraft, to describe its attitude in flight. I would not want to have a trailer's towing abilities, measured in how well it endured the three axis. If it were, it would be an indication of a very traumatic event.

As has been posted, many slant trailers' stalls differ in size from manufacturer to manufacturer. Many offer various sizes, divider angles and box lengths to custom fit most any horse. If you are purchasing used, a tape measure is a useful tool. If size is a concern, shop for "warmblood" trailers, those that are generally equipped with stalls for larger animals.