Sight. Horses see well, even in very dim light, but in familiar settings, they don’t always pay attention to what they see. For instance, if the water tank has always been in a particular corner of the field and you move it to another place, the horse may look at the tank in its new position and then walk to where the water used to be, seeming bewildered when that corner is now empty. The same thing may happen if you always feed hay in the same location in the pasture. Some horses catch on to the changes more quickly than others, and most will eventually come across the water or hay by accident, but it’s not a bad idea to lead your horses to the new locations a time or two. Don’t assume that they’re just not hungry or thirsty! This is especially important for older horses that may have done the same thing in the same way for a long time.
Smell. The sense of smell is well-developed in equines. For this reason it’s wise to keep the horse’s feed tub and water bucket clean because a moldy or stale smell can keep the horse from eating or drinking. Horses will often (not always!) refuse feed or hay that is only slightly moldy and seems fine to the owner. For horses that won’t touch water when away from home, it’s sensible to take a supply of familiar water when you go to a show or trail ride. There may be nothing wrong with the water at the event, but if it smells odd to the horse, chances are he will not drink, even if he’s thirsty. Familiar water in a new bucket may have the same effect.
Taste. This sense is closely related to smell, and is one reason why changes in feed or hay types should be made gradually by mixing a bit of the new with a larger portion of the old, adding more of the new product each day over the course of a week or so. This practice allows the microbial population of the horse’s hindgut to adapt to the changes as well, but if the horse won’t eat the new feed, this is beside the point. Equines are also good at detecting when an additive, supplement, or medication has been mixed into their feed. They might refuse the feeding completely, or might carefully eat around the strange powdered or pelleted substance, leaving it in the bottom of an otherwise empty feed tub. Mixing these additives with applesauce, pancake syrup, or yogurt before putting them into the feed sometimes helps.
Hearing. Horses have a fine sense of hearing. They can easily hear feed buckets being filled at the other end of the barn, and can hear the crinkly sound of a peppermint candy being unwrapped at about the same distance. To avoid upsetting the most anxious equines, feed them first and then see to the more patient ones. If there are horses in the barn that don’t get grain at all, consider dropping a few hay cubes into their feeders at mealtimes.
Touch. If you’ve ever watched carefully as your horse grazes, you will notice that he sorts through the forage, using his lips to push aside the less appealing plants as he selects something he likes better. Smell and taste are also used, but touch is important; the horse can’t see what is directly under his nose, so he trusts his sensitive lips to avoid eating tough or prickly growth. These lips are also able to reach into blackberry bushes, pick the ripe fruit, and carefully back out without getting scratched! Likewise, if the horse puts his nose into his feed tub and encounters something he doesn’t expect, such as a big hairy caterpillar, he may jump back, snort, and stamp his feet in frustration.
If your horse shows a feed-related reaction that you don’t understand, consider what signals he may be processing through his sight, smell, hearing, taste, or touch. Keeping the horse’s senses in mind can explain some equine behavior and help owners avoid upsetting their horses’ feeding routines.