Horse Respiration and the Equine Heart Rate
Moving Well by Breathing Well
By Jec A. Ballou
At some point, most riders aboard a horse that is breathing heavily will draw a conclusion about its fitness. Respiration, though, can be a fickle fitness marker. And it might sometimes tell you more about a horse’s mental state, physical tension, or plain old natural aptitude than about his current fitness. Respiratory rates are always telling us something important. The key is figuring out what the message is.
An unfit horse will indeed breathe heavily and hard when exercised. Our goal with better conditioning is to see the horse perform the same degree of exercise with very little elevation in his respiratory rate. Occasionally, however, a well-conditioned horse will still get winded when exercising at only a moderate level. This is explained by several factors including the need to shed heat, a humid environment, underlying fatigue or a stressed immune system, dehydration, carrying extra weight, or poor air quality.
Most often when a horse with reasonable fitness begins panting during a routine trail outing or arena session, he is hot and trying to cool down. This is especially true for senior horses and naturally heavy-bodied breeds. It would be a miscalculation to automatically assume in this case that the horse is not fit enough for the task at hand and that activity should be ceased.
Instead, the horse’s heart rate is a more accurate indicator of this, and it would be a good idea to take a reading to compare to his breathing rate. If the heart rate is in a normal range (32 to 40 beats per minute) but the horse is panting, he is likely just hot. Does this mean you should stop what you are doing? Not necessarily. Make a habit of recording the time it takes your horse to regain a normal resting respiration rate when you pause activity. A horse’s average respiration rate at rest is between 8 and 15 breaths per minute. In hard efforts, it can briefly jump to 100. A hot horse will take rapid, shallow breaths in order to dissipate heat. The only time for concern is if breathing becomes laboured, irregular, or it remains higher than his heart rate.
Related: Cross-Training Fitness Test
If he regains a resting rate within five minutes, it is generally fine to carry on with your ride. But if he keeps panting for well over 10 minutes (and his heart rate is in a normal range), it is worth stopping and figuring out ways to modify your schedule to exercise him without generating so much heat. First, can he lose some weight? Can you ride when it is cooler outside? Can you pre-cool the horse by wetting his body before riding? If the heart rate is not in a normal range and he is panting, he has exceeded his fitness level.
The take-home message is that as your horse’s fitness increases, using respiratory rates as your primary marker is not entirely accurate as discussed above. But even when not providing fitness calculations, respiratory rates are always telling you something important.
Very often, horses’ breathing rates get compromised from stress or physical restriction, which is unfortunately overlooked during training. When a horse does not breathe rhythmically and deeply, does not blow out through its nose regularly throughout a ride, or makes little grunting noises at trot and canter, its respiration becomes compromised. This means less oxygen is taken in and shuttled — along with blood — to working muscles, which in turn leads to faltered nerve signals. Put simply, the horse cannot move with ease and balance, and the programming for correct movement will not take place.
Any number of factors might cause a horse to hold its breath during exercise, including tension and anxiety. Common explanations include conformational issues, sore feet, and muscular imbalances. Regarding conformation, horses with wide jowls or thick poll muscling can suffer when asked to work in a collected frame. The nasopharynx and larynx can become obstructed due to this extra fleshiness and impair airflow. Similarly, blockages in the lower cervical vertebrae can compromise the phrenic nerve, which exits here. This is a major nerve that controls breathing. The nervous system’s communication to the diaphragm then weakens along with oxygen uptake and utilization.
The diaphragm has attachment points along the lower back and rear portion of the ribcage. If a horse has overly tight loin muscles or intercostals between his ribs, the action of the diaphragm will be hindered. Sometimes horses that were worked too early in collection also have tension or imbalance in the scalene muscle at the base of their necks. This muscle helps stabilize the ribcage and plays a role in respiration. If it cannot function well, the horse will move with short choppy strides and shallow breaths.
These are just a few of the most commonly restricted areas among shallow breathers, and I offer them as a starting point for your own exploration of whether your horse is breathing in a way that leads to better mechanics and fitness. For students to whom this is new territory, I offer the following tips:
First, take note of how long it takes your horse to first blow through his nose during any session. Is it within the first five minutes? Excellent! Is it longer than 25 minutes? Uh-oh, he is holding his breath.
Second, listen to your horse’s breathing when cantering. Mother Nature wired a horse’s nervous system to breathe during canter by coupling his breathing rate with his stride rate in a 1:1 ratio. For every canter stride, the horse needs to breathe in and out once. The exhale should be audible. Imagine the forceful, rhythmic exhalations of a galloping racehorse or eventer.
One of my mentors is fond of saying that when your horse blows through his nose, it is like he gives you a bouquet of flowers. I enjoy counting how many bouquets of flowers I can accumulate during a ride. This metaphor captures the beauty and pleasure of a horse that is moving well by breathing well.
Related: How to Check Your Horse's Vital Signs
Main Photo: Shutterstock/Rolf Dannenberg