Whole Horse Q&A

Lip-Smacking Good? Not So Much


My 14-year-old Quarter Horse  mare smacks her lips together. It started occasionally during shoeing or a vet exam. Now she does it while being tacked up, when on the trail, and even while just standing. I know it's not dangerous, but it's extremely annoying. What can I do?



Lip smacking, as you've witnessed, is a repetitive oral behavior. Such behaviors can be associated with mouth disorders or pain in another part of the body (such as stomach ulcers leading to cribbing). Not enough roughage in the diet also has been linked to some mares will repeatedly open and close their mouths with a relaxed face (droopy lips, ears to the side) in a manner similar to the champing or yawing of foals. Usually this is done in response to the presence of a stallion.

Note when your mare performs her lip smacking, as this may give you clues as to what might be the cause. In this case, if it began in potentially stressful situations, such as farrier and vet visits, it may well be a displacement behavior that's generalized to some other less stressful contexts.

Unfortunately, it's hard to teach a horse simply not to do something. Punishment (yelling, smacking, etc.) may stop the behavior temporarily, but rarely cures it. Moreover, it creates a negative association with the person administering the punishment. It also fails to address the underlying motivation for the behavior (and actually worsens stress/anxiety). Finally, it may even cause the horse to associate the punishment with the context (being tacked up, for example), rather than the problem behavior itself.

For these reasons, the best behavioral treatment is to identify and remove the motivation, and/or teach the horse an alternative behavior.

You can remove motivation by decreasing the unpleasantness of the experience that brings on the behavior (for example, ask for the mare to be sedated for uncomfortable veterinary procedures), and/or pair it with something pleasant (say, the presence of a horse friend).

To teach an alternative behavior, give your mare something to do that's more attractive to her than lip smacking, such as munching on hay during veterinary procedures, shoeing, and tacking up. Alternatively, use her favorite treats to reward any behavior other than the undesirable one.

To do this, watch her closely in at-risk contexts, and reward her before she lip-smacks (or at least not during or immediately after). Then reward again (and again and again.. .frequently at first!) as long as she's not engaging in the behavior. Over time, she should lip-smack less and less, and eventually you can reward just intermittently.

Or consider teaching your mare to "target" something with her muzzle (such as a spot on the wall or a quirt with a marker on its end), for a reward. First reward her for moving her muzzle near the spot, then for touching | it, then for more and more prolonged contact with it. Eventually, you'll be able to have her sort of "park" her muzzle on the target, while you reward her intermittently.


PhD Candidate, Veterinary Sciences


Faculty of Veterinary Medicine,

University of Montreal


For a lot more on why horses do the odd things they do, type  behavior  into the search box at HorseandRider.com.