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.