All horses, regardless of their lifestyle and work level, require salt as a regular part of their diet. How much salt each individual horse needs may change depending on what they do each day, but they all need it. There are a few different ways salt can be offered to a horse.
Offering a white salt block – this is the easiest, most convenient way to offer salt for most owners. It comes in a small 3 to 4 lb block size or a large 50 lb block size. The idea is that a horse can lick the block to get whatever salt they need. If this is the route you go, make sure to keep the block clean and enticing to the horse (a ground block pan or wall holder can help with this) and ideally protect it from rain and water.
Feeding loose white salt with a grain meal or over dampened hay. If your horse is working hard or sweating a lot they may have a higher salt need than they can get simply from licking a block. Some horses also have sensitive tongues and find licking a hard block too abrasive. A good place to start is 2 level tablespoons of salt added to their feed daily. Be sure to gradually introduce a small amount of salt to their meals each day until you reach the full 2 tablespoons or your horse may refuse to eat the suddenly salty meal. If your horse is getting grain, a mineral supplement, or has access to a red mineral block (more on those later), you can use plain, non-iodized table salt as they are likely getting enough iodine already.
If feeding a loose, granulated salt with their grain or hay is too much for your horse and they won’t eat it, you can offer loose, granulated salt in a bucket for them to have free-choice access to. This is a middle ground between a block and top dressing on their grain/hay. Just make sure to protect the bucket from rain/moisture and to check regularly and break-up the loose salt if needed when it forms a block/chunks in the bucket. Using Kosher salt may help as well as it generally has a much coarser texture.
Red mineral blocks and when to offer them can be confusing for owners. When necessary, these red mineral blocks should be offered alongside of white salt. If your horse is receiving daily grain or a vitamin/mineral supplement, they likely are getting all the minerals they already need and you do not need to offer a red mineral block. However, if your horse is on a hay or pasture only diet, offering a red mineral block is a good idea.
How do you choose between the different red mineral blocks? There are mineral blocks labeled for horses specifically or “livestock” (including horses). Either of these should be safe to offer your horse.
Avoid mineral blocks sweetened with molasses as this can cause horses to over consume from them and give them accidental mineral toxicities.
Do be aware of whether or not the block is labeled as safe for sheep if you have any sheep that will have access to the block. Some mineral blocks that are safe for horses have unsafe copper levels for sheep.
There are also mineral blocks with and without selenium. Selenium is an essential antioxidant that horses require in their diet. In many areas of the country, selenium levels in the soil are high and our horses get plenty of it by simply grazing and eating hay. Many grains and supplements also contain enough selenium for most horses. However, in the upper great lakes region, including Wisconsin, our soil is low is selenium. If your horse eats hay grown in Wisconsin, does not get much grazing in the pasture, and does not regularly get daily grain or mineral supplements, offering a mineral block that contains selenium is a good idea.
Finally, horses that have not had access to salt can consume too much too soon when it is first offered. Rapid changes in blood and brain cell levels of salt are very dangerous. If you bring a new horse home that is ravenous for salt, it is best to limit the amount given or restrict access to the block so the horse's salt composition adjusts gradually. Sick horses benefit from blood chemistry panels to determine which, if any, salt or electrolytes they need supplemented, and if their kidneys are able to balance the levels properly.
As always, I'm here to help, so please call or email if you have any questions. Thanks for reading!