Uncapped T-posts.

Impalement is never pretty.

This horse was lucky ... he'll live, and probably make a decent recovery.

Horses impaled through the chest when panicked and attempting to jump ... not so lucky.

T-post caps were made for the purpose of protecting your horse from impalement. Use them. Better yet, are T-post sleeves.

Better than both ... wooden posts. More expensive to install, and worth it.

Wood plank fence.

This looks like a very sturdy wood fence, suitably tall for the horse kept inside.

The bottom plank is close enough to the ground to prevent pushing under, yet not too close so that a hoof is unlikely to get caught under.

It would be somewhat safer to mount the boards on the inside of the posts, so that the posts themselves do not become a hazard, and so that if horses are pushing on the planks, they are less likely to push the planks out of the posts if the nails are not secured well enough.

Whatever fence can be cobbled together.

I can't even determine exactly what kind(s) of fences are being used here.

I see sharp broken wire protruding, and what is possibly an electric tape that is loose and most certainly not properly electrified.

Plus, non-breaking nylon halters should not be left on for turn-out.

(They do sell nylon halters with a leather break-away crown, for those of you that can't catch your loose horse otherwise.)

Never, ever safe.

I don't care how old and gentle and lazy and unspookable you say your horse is.

I don't care if you say he respects the fence and is too smart to get caught up in it.

I don't care if you've used barbed wire for 200 years and NEVER had an accident.

Barbed wire will never be acceptable fencing for horses, IMHO.

Poly/vinyl rail fence.

For pastures with foals, it would be better to have a somewhat taller fence with a fourth rail closer to the ground, so a rolling foal could not roll under the fence and find itself separated from its mother, and panic.

Yes, I can find fault with pretty much any fence! My own included—to be featured later on.

Welded wire fence.

This type of fence can make great horse fence, BUT it must be tall enough AND must be topped with an electric wire, or better, a wood plank, to prevent horses from "riding it down" as you can see has happened here.

The openings in the fence are small enough that hooves cannot fit through. This fence is typically used for chicken runs, goats and smaller livestock, so make sure the height of the fence is adequate.

The other problem you will run into with this type of fence used for horses, is securing the bottom of the fence to prevent horses from reaching under it, WITHOUT creating a dangerous possibility of hoof entrapment.

Barbed wire, again.

Only unsafe if you consider losing an eye a bad thing.

As the owner of a one-eyed horse (cause having nothing to do with fence issues) I can tell you it is most interesting, and I wouldn't recommend it.

Barbed wire, loose and low.

These two look like pretty nice horses, from what I can see.

Why on EARTH are they kept in too low, too loose, too dangerous fence?

Metal pipe fence.

Metal pipe fencing has many fans. Properly installed and maintained, it is considered one of the safer options.

While I'm not the biggest fan of it, I also have never used it or been at a farm where it was the primary fence type, so I'll try to reserve judgment.

As with all fence, maintenance is as important as installation. Care must be taken to prevent rust and watch for bends that could turn into cracks and exposed sharp edges.

Barbed wire over heavy gauge high tensile wire.

Oh, poor sweet face. This pony is saying, SAVE ME!

What happens when that blanket gets good and stuck on a few flesh-ripping barbs?

There ARE alternatives.