Your new horse swishes his tail, pins his ears, and swings his butt to the side every time you pick up the left lead. When you bought him, his previous owner told you, “Oh don’t worry about it, he’s always done that. It’s just normal for him,” but now you’re not so sure. Is it really normal? Or is he hurting?
Great question! In fact, it’s just this type of scenario that caused researchers to start asking what behaviors horses exhibit under saddle that might mean there’s something wrong. After all, would you really want to force your horse to perform a straight transition if he’s simply saying that he hurts? Most horse owners would say no. And you might be surprised to learn that studies indicate as many as 50% or more of horses that owners think are sound are actually lame.
How Do We Know If He Is Hurting?
How can that be? Lameness that is “subclinical” or mild enough that it’s difficult to recognize may go undiagnosed, but still be a source of pain. And bilateral (impacts both front of both hind legs) or multi-limb lameness can easily go unnoticed. Forcing a horse to perform when he’s hurting is an important welfare issue. We owe it to our horses to make sure they’re comfortable in their work.
In an effort to protect our equine athletes, and perhaps put a stop to coercive or harsh training methods that can sometimes be employed to overcome “bad behavior” that might actually be due to pain, researchers in the U.K. have developed a tool called the Ridden Horse Pain Ethogram (RHpE).
In this article, I’m going to introduce the basics of the RHpE. I’ll tell you what it is, how it was developed, and how it can help you evaluate your own horse’s behavior.
All About the Ethogram: A Guide to Finding Pain
An ethogram is a catalog of animal behaviors that are specific and easily identified, meaning they’d be uniformly recognized by different observers. Observation and tracking of these behaviors are put to use in animal-behavior studies to help scientists determine what story the behaviors tell about the animal’s activities or mental and physical state. For example, an ethogram of behaviors exhibited by polar bears might be used to help researchers understand when they are stressed, such as when they exhibit repetitive pacing behaviors commonly seen in zoos. The RHpE was specifically developed to help understand when working horses might be in pain.
Researchers who developed the RHpE initially looked at 117 behaviors exhibited by horses while being ridden. Through a process of elimination, 24 behaviors were identified that were more commonly seen in lame horses than in non-lame horses. (See sidebar on page 68 for a list of these behaviors). During early studies most of these behaviors were 10 times more likely to be seen in horses that were lame than in horses that were sound. To validate these findings scientists discovered that many of these behaviors could be stopped by doing something like a nerve block to eliminate the source of pain.
After the list of potential pain-related behaviors was identified, the next step was to come up with a meaningful way to use the RHpE. Through further work, researchers determined that horses exhibiting eight or more of the 24 behaviors were likely to have some underlying musculoskeletal pain. Based on this work, the RHpE has been proposed as a tool that owners, trainers, and veterinarians can use to help determine whether a horse might be in pain when working.
What the Critics Say
Does this mean any time a horse exhibits any of these behaviors it means he’s lame? Absolutely not! In fact, one of the limitations of this work is the potential impact of influences other than pain that might contribute to the incidence of these behaviors. Confounding factors might include confusion, lack of ability to perform requested maneuvers, or the impact of the rider. Tight saddle tree points, the rider being positioned at the back third of the saddle, and even rider weight have all been shown to increase the incidence of some of the behaviors in the ethogram.
Additionally, critics express concern that the proposed ethogram doesn’t meet the “scientific rigor” necessary to be put fully into practice. Although efforts have been made to define the behaviors as specifically as possible, there are still discrepencies. Some, such as the horse “exhibiting an intense stare (glazed expression, “zoned out”) for 5 seconds or longer” are still fairly subjective and depend on interpretation by observers.
Weighting of Behaviors
Additional concerns include the equal weighting of behaviors in the count. Even though some correlate more strongly with pain than others, and a lack of mutual exclusivity in some of the behaviors such as “mouth opening and/or shutting repeatedly with separation of teeth, for 10 seconds or longer,” and “tongue exposed, protruding, or hanging out, and/or moving in and out repeatedly” that may happen hand-in-hand.
Finally, behaviors highlighting asymmetry, such as “hind limbs do not follow tracks of forelimbs but repeatedly deviate to left or right; on three tracks in trot or canter” are commonly observed with inherent asymmetries of the horse or even of the rider, unrelated to pain.
A final drawback that limits application of the RpHE to all equestrian disciplines is this. The work to develop this ethogram was done on horses trained to perform in the “on-the-bit” position with the front of the head maintained on the vertical. While it’s likely many of the behaviors will carry over to different styles of riding, it remains to be proven whether the findings will be consistent in horses engaged in sports like endurance or trail riding where requirements are different.
While there may be limitations, the RpHE is still a valuable tool. And its development is a big step forward for anyone concerned about the welfare of our equine athletes. Consider how learning more about the RpHE might help you determine whether your own horse hurts.
What This Means for You
Perhaps the most important result of this work is the light it shines on why your horse’s “normal” behaviors may not really be OK. Just because he’s always swished his tail, pinned his ears, and swung his butt to the side when you pick up the left lead doesn’t mean he isn’t sending you a message. And it’s possible that message is “I hurt.”
If you want to put the RHpE to use, start by familiarizing yourself with the behaviors on page 68. Next, ask a friend to videotape you riding your horse after a 10 to 15 minute warm-up period. You should plan to video between 8 and 10 minutes of work at the walk, trot, and lope and include both circles and transitions. With the RHpE chart in hand, count the number of behaviors you observe. (For even better accuracy, have your friend evaluate the video alongside you. Better yet, get together with a group of friends and work together. The more observers you include, the more accurate you’ll be.)
Did you detect eight or more of the behaviors listed on the RHpE? If so, it’s time to do some additional investigation:
Schedule a lameness examination with your veterinarian. Even when a horse isn’t obviously lame, your veterinarian may be able to detect signs of musculoskeletal pain during a clinical exam. The exam might include palpation, stress tests, and watching your horse move. If your vet detects evidence of pain, they’ll likely perform additional tests to localize the source of lameness. Such as diagnostic blocks or nuclear scintigraphy, or imaging, such as radiographs or ultrasound to determine an underlying cause.
Ask about other potential sources of pain. Your vet might recommend gastroscopy to evaluate for stomach ulcers. Or, a dental exam, or lab tests that could indicate muscle abnormalities.
Consider saddle fit. Tight tree points on a saddle can contribute to the behaviors that are attributed to pain in the RHpE. A well-fitted saddle, proper padding, and correct girth or cinch adjustments are all important to evaluate. Especially if your horse is exhibiting signs of pain when ridden.
Look inward. It may be hard to admit, but there’s always the chance that you are contributing to your horse’s discomfort. Could your own imbalance in the saddle, conflicting cues, or lack of knowledge be contributing to your horse’s pain. Or are you simply leaving him confused? Consider asking a skilled trainer to ride your horse and see if his behavior improves. Perhaps you are simply expecting more from your horse than he is capable of giving. A thoughtful trainer can help you decide.
If all else fails, ask your veterinarian about an NSAID trial. This involves administering a pain-relieving medication such as phenylbutazone (“bute”) or flunixin meglumine (brand name Banamine) for a period of time while your horse is still in work. If his score on the RHpE improves while on the medication, you may have more work to do. Turning toward training methods (especially harsh ones!) to correct behavior might not be in the best interest of your horse.
Not only can the RHpE help you identify if your horse is hurting, but it should also lead you down a path of determining where and why. Once a source of pain can be determined, seek out treatments that will minimize or eliminate his bad behavior. Even if he isn’t behaving really badly, by addressing subtle musculoskeletal pain you may improve your horse’s performance. Some of the most recent work by researchers developing the RHpE showed that the most successful competition horses had the lowest scores, while those with higher scores were more commonly eliminated or finished at the bottom of the class.
Never forget that your horse isn’t out to make you miserable. In fact, chances are he aims to please. As the RHpE becomes more refined and widely used, we can hope this tool will lead to happier athletes—both horse and human!
The 24 Behaviors of the Ridden Horse Pain Ethogram
1. Repeated changes of head position (up and down), not in rhythm with the trot.
2. Head tilted or tilting repeatedly.
3. Head in front of vertical (greater than 30 degrees) for 10 seconds or longer.
4. Head behind vertical for (greater than 10 degrees) for 10 seconds or longer.
5. Head position changes regularly, tossed or twisted from side to side, corrected constantly.
6. Ears rotated back behind vertical or flat (both or one only) for 5 seconds or longer; repeatedly lay flat.*
7. Eyelids closed, or half closed for 2 to 5 seconds; frequently blinking.
8. Sclera (whites of the eye) exposed repeatedly.
9. Intense stare (glazed expression, “zoned out”) for 5 seconds or longer.*
10. Mouth opening and/or shutting repeatedly with separation of teeth, for 10 seconds or longer.
11. Tongue exposed, protruding, or hanging out, and/or moving in and out repeatedly.
12. Bit pulled through the mouth on one side (left or right), repeatedly.
13. Tail clamped tightly to middle or held to one side.
14. Tail swishing large movements: repeatedly up and down/side to side/circular; repeatedly during transitions
15. A rushed gait (frequency of trot steps greater than 40/15 seconds); irregular rhythm in trot or canter; repeated changes of speed in trot or canter.
16. Gait too slow (frequency of trot steps less than 35/15 seconds); passage-like trot.
17. Hind limbs do not follow tracks of forelimbs but repeatedly deviate to left or right; on three tracks in trot or canter.
18. Canter repeated leg changes in front and/or behind; repeated strike off wrong leg; disunited.
19. Spontaneous changes of gait (e.g., breaks from canter to trot or trot to canter).
20. Stumbles or trips more than once; repeated bilateral hindlimb toe drag.*
21. Sudden change of direction, against rider’s directions/cues; spooking.
22. Reluctanct to move forward (has to be kicked +/- verbal encouragement); stops spontaneously.
23. Rearing (both forelimbs off the ground).
24. Bucking or kicking backward (one or both hind limbs).