The Royal Dick School of Veterinary Studies in Edinburgh has recently highlighted something that I have been preaching for years: Take care when rugging your horses, you might be doing more harm than good! The one difference between the Dick School and myself is that of course they backed it up with scientific facts, while I had just heard and read it somewhere.
So, I thought perhaps it’s time to change my ways and back up my preaching with the evidence that I can find out there. I went on a search and I really don’t want to step on anyone’s toes but if your horse is young, healthy and does not belong to one of the thin-skinned breeds native to hot countries, please read the below and reconsider rugging through the comparatively mild winters that we get here in the UK.
“But it’s freezing!”, some people may exclaim.
Yes, I totally agree. The other day I was contemplating if I should wear a hat to go out. It is so easy to forget that just because I find it a bit chilly when I leave the house in the morning, that does not mean my horse feels the same way. Horses have a much more complex system of thermoregulation that we tend to give them credit for!
The Dick School explain, that our thermoneutral zone is much higher than that of our horses. That means the human body has to make use of its energy resources to keep regulated when temperatures are outside the 20 to 35 degree range. A horse’s thermoneutral zone is between 5-25 degrees. That means when I feel a chill, my mare is in fact perfectly happy. However, this also implies that she will struggle more when it is hot so we need to take caution in the summer.
The Dick School also point out that the caecum (basically what we call appendix in humans) “acts as a giant internal combustion engine producing heat.” Our equivalent of this organ is tiny so of course this is not something we could relate to at all.
One thing I always heard or read was that horses have excellent thermoregulation and that rugging them impacts on their ability to do so. I must admit though that this has been a vague concept to me so I went on a hunt to find more information about this. I found this very informative article (in German) on a portal that mostly discusses homeopathic remedied – and hooray, all the facts are backed up by referencing scientific studies! After studying this, I have come to the conclusion that the equine body is an astonishing clever organism that has several mechanisms in place to make sure that it can comfortably endure in varying temperatures. Horses are literally thick-skinned, which provides them an isolation layer and changing from summer to winter coat obviously also helps. There is more to the fur than meets the eye though: The hairs react to outside temperature by either lying flat to the body or standing erect, a similar effect to goosebumps in humans only that our poor excuse for hair means that we still freeze. I am sure you have seen this on plushy ponies during the winter months but all horses are capable of this. Here is an interesting fact though: Goosebumps (in humans or horses) are caused by the contraction of the arrector pili muscle. Like any muscle in the mammal body, the arrector pili must be used on a regular basis to maintain regular functioning order. The implications of this are actually scary as this indicates rugging or clipping your horse could in fact have long term effects on its ability to effectively use its hair for thermoregulation!
There are also a number of interesting internal processes in place that keep a horse warm. For example, equine arteries can adapt and widen or narrow with temperature. In warm temperatures, the widened arteries allow for a lot of blood to be carried to the skin surface. That means that the blood can be cooled down the air (that in any case will still be cooler than the body temperature of the horse) and hence cools the body. When it’s cold, the arteries close and with less blood flowing through the surface of the skin, less of the internal body heat is lost.
Clipping and wearing a rug not only disrupt the natural process of thermoregulation though, the Dick School further point out that it can cause heatstroke, stress and colic, especially during autumn when temperatures still vary. Furthermore, it can affect the natural weight loss cycle over winter. That means that horses and ponies coming out of the summer slightly obese will stay so, magnifying the risk of laminitis and other diseases in the spring.
Please don’t get me wrong though: I am not saying that you should never rug your horse. If your horse is old, prone to illness or was recently imported from Spain or North Africa, please help her or him get through the winter! If you do need to rug your horse, please do consider what is appropriate for the current climate though – a heavy weight rug in September may be well-intended but probably doesn’t actually help. You can find a quick guide that may help you decide on the appropriate rug here.
The Dick School reference a survey in which they found that peer pressure was the most likely reason for horse owners to start rugging their horses. I would be lying, if I couldn’t relate. When September came, very few horses at are our yard were not rugged. It seemed to me that only Vanity and her bestie, a semi-abandoned gelding were the only ones all “naked”. I was starting to doubt whether she is really happy out there in the cold all day and night. In my case these doubts fuelled a desire to dig a bit deeper into this topic and find out if Vanity can really stay warm while I am freezing off my limbs.
Perhaps that serves as a good concluding remark, do your own research and decide what is best for your horse. Don’t just go with the flow. That also means questioning what you read on blogs like mine because despite all of the above: rugs are not the devil. Used in moderation they may be a great aid. Even I use rugs – I don’t clip, so cooler rugs are my best friend in the winter! If temperatures fell below -10 and -15 or if I saw Vanity struggle with the cold I would of course consider helping her keep warm, too. As of now, however, she is unrugged, unclipped, still lives out 24/7 and is loving life!
Does your horse currently wear a rug and how did you come to that decision?
Please feel free to leave comments or questions below!