Yesterday I talked about hobbles as a way of restraining horses in the wilderness. Some people think hobbles are cruel, but many horsemen consider them a better alternative to picketing a horse when possible, simply because the horse can still graze and move.
Tethering horses is also controversial. A horse is generally tethered using a collar around the neck and a chain secured to a stake in the ground. Some people may also tether using a halter or headcollar, but a neck collar is more traditional...and harder for a horse to get out of when left unattended.
Like hobbling, tethering a horse allows the animal to move and graze within a restricted area, but it's often considered cruel. This may be because it's a method used by traveling peoples such as the Roma. It's also common to see donkeys tethered in Mediterranean countries where fencing is somewhat scarce.
The two issues people tend to focus on are excessive limitation of the horse's movement and the perceived cruelty of using chains.
Tethering is a method that should not be used to hold a horse in one place - a tethered horse needs to be moved daily or it will eat all the grass in its limited area. And, of course, the horse should be provided water regularly. (In some countries, there are problems with horses being tethered for extended periods on somebody else's land, which is not healthy for the horses or the land).
As for the chain - believe it or not, a chain is a safer and more humane way to tether a horse than a rope. When the horse moves to graze, the chain will immediately drop back to the ground. A rope will stay at about fetlock height - risking the horse tripping or becoming tangled in it, which can cause serious injury.
This horse (image source: J Thomas) has been tethered incorrectly with a headcollar and a rope, but otherwise looks in good condition...I think he might be hoping the photographer has peppermints.