The question of whether, and if so, when, one should let our Icelandic horse wear a rug is always the subject of heated discussions. We think that, just as with clipping, there is no universal answer to this question and you always have to look at each horse individually. And to make it easier for you to decide whether your horse needs a blanket, we have compiled some important facts.
When the thermometer drops below 10 degrees, we get out our thick winter jackets and from 5 degrees most of us are only at the stable with overalls, thermal breeches and lined shoes. And we often think that our horses, despite their thick coats, must feel the same way and are also cold.
Comfort temperature of horses: plus 25 to minus 15 degrees
But this is not the case - at least not most of the time! The comfort temperature of horses in mild climates (i.e. ours) is between plus 25 and minus 15 degrees. At 5 degrees, the metabolism functions optimally - assuming dry weather. For comparison: for us (naked) humans, it is between 25 and 30 degrees! And contrary to what we often think, horses only start to produce additional heat by boosting their metabolism at around minus ten degrees.
There are so-called harpal muscles on the horse's coat hairs. These are responsible for raising or laying down the hair - depending on the temperature. When it is cold and the hairs are erected, a warming layer of undercoat develops, which is protected from moisture by the tallowy outer hairs. When you dig in your horse's coat with your hands, you can feel how warm and cosy it is.
By the way: not every Icelandic horse is a plush ball! Icelandic horses from the south-west of the island, which is influenced by the Gulf Stream, usually have a shorter and finer coat than Icelandic horses from the north-east of the island, which is more sub-polar. It is also interesting that large horse breeds do not freeze more than our fluffy Isis due to their shorter fur, because the large horses have less body surface in relation to their body mass and therefore less heat loss. This seems to be the reason why ponies and foals have longer and thicker winter coats than large horses and why the same species is smaller and stockier when it is at home in cold climates. (Source: Badische Bauern Zeitung)
Cold stimuli are important for thermoregulation
Muscles - including hair follicles - need sufficient training. Therefore, thermoregulation only functions adequately if the horses are regularly confronted with cold stimuli. By the way, cold stimuli are perceived by the tactile system, the so-called sense of touch. And it works (simplified) like this:
The thermoreceptors perceive stimuli such as cold and heat and pass them on to the central nervous system. This processes the incoming information and then gives a corresponding command to the responsible muscles - in this case the hair follicle muscles - which then react accordingly and either erect or lay down the hair. This process takes place unconsciously and permanently (by the way, not only in horses, but also in us humans). If the receptors register too much heat, the horse has the possibility to either cool the body (vasodilatation) or to avoid heat loss (vasoconstriction) by constricting or dilating the arterial vessels - again a muscle action. If the vessels are constricted, the blood flow in the ears, hooves and legs is reduced and the blood is instead used more to protect the vital internal organs. Vessel dilation causes increased body heat to be released. If this is not enough, the horse begins to sweat in order to cool itself down. If you are interested in the topic of tactile perception and would like to learn more about it, then take a look at Karolinas Seite 360° Pferd .
If a horse is permanently wearing a ruf, its thermoregulation does not function sufficiently because it does not perceive enough cold stimuli. This is a point that many critics of blankets make again and again. In addition, especially in spring and autumn, when there are strong temperature fluctuations, there is a risk that a horse may overheat under the blanket and have to cool down by sweating. However, this makes the blanket wet and when it gets cold at night, the horse freezes under the wet blanket but cannot put up its insulating coat. Regular re-blanketing is then necessary.
Study: To put a blanket on or not to put a blanket on - possible effects on the horse's well-being
By the way, there is also an interesting study on the subject of body heat and horse rugs by Kim Hodgess from the Duchy College in Devon in Great Britain with the title To rug or not to rug: potential impacts on equine welfare: Potential impacts on equine welfare). The study looked at the surface temperature of the body in the context of adequately functioning thermoregulation. We say straight away: The study is only based on a small data set and some points are not taken into account. In addition, mostly box horses and no Icelandic horses took part. Nevertheless, the result is interesting:
For the study, the surface temperature of 13 horses was measured: Three of them were covered with an eczema blanket, six of them with a fleece blanket, two had lightly lined blankets on and two other horses were not covered at all. The temperature was recorded for 24 hours.
The ambient temperature was about 4 to 4.5 degrees and the surface temperature of the horses without blankets was 12.5 to 18.5 degrees. The eczema blanket caused the surface temperature of the horses to rise by about 4.2 degrees, the fleece blankets by 11.2 degrees and the lightly lined blankets even by 15.8 degrees! Thus, well-intentioned but unfortunately wrongly chosen blankets can cause a temperature that is far above the horse's comfort zone. (Source: International Society for Equitation Science)
When does it make sense to put on a rug on an Icelandic horse?
A healthy horse that is kept in a species-appropriate manner does not need a rug in the vast majority of cases - at least not permanently. It is often argued that a horse develops less coat if it is covered in time. This is only partly true, because the change of coat depends on the amount of daylight. We cannot say at this point whether early covering really influences the amount or density of coat, because we do not know of any studies on this. However, considering the horse's comfort temperature and the temperature development under a rug, we do not think it is advisable to put a rug on the horse permanently in mild temperatures.
Nevertheless, there are also good reasons for temporarily covering an Icelandic horse.
clipping for particularly heavy sweating horses
If a horse is shorn over a large area, it has problems keeping warm on windy and wet winter days, because it no longer has a warming undercoat and dry-keeping topcoat on the shorn areas (you can read more about shearing here).
Little subcutaneous fat tissue
Old, sick and very thin horses with less subcutaneous fat tissue or horses in convalescence should also wear a rug, depending on the weather. We deliberately say depending on the weather, because sweating is unhealthier for a horse than freezing (we have collected important facts on the subject of heat regulation and sweating here). Overheating strains the circulation and can even lead to colic.
The horse's body fat plays an important role in the question of whether to cover the horse or not, because the skin, together with the subcutaneous fat tissue, forms an insulating layer. This is why wild horses gain up to 20 percent in weight in autumn and this can also often be observed in our Isis in the open stable. If a horse lacks the necessary subcutaneous fat, it cannot warm itself sufficiently on very cold and wet days.
One more note about the old horses: The ability to thermoregulate slowly deteriorates in horse oldies (25+). Therefore, old horses should be adequately protected during frost and cold easterly winds.
A horse that is completely soaked from rain and snow and freezing should wear a blanket at least until the coat is dry again. If the horse is wet and sweaty after training, we recommend our classic sweat rug made of fleece.
By the way, we also recommend this if you take your horses to a larger stable or to a course in the cold season and your horses are sweaty. To prevent your horse's muscles from becoming tense on the subsequent trailer ride and to allow the coat to dry, it is advisable to put on a blanket. We recommend our woollen blanket for this purpose.
Cold leads to higher muscle tone in the back and wet and windy weather in particular can cause muscles to tighten and worsen possible disease findings such as kissing spines. Also, the fascia tightens and can stick together, which can eventually cause the tissue to lose elasticity. For this reason, affected horses should consider wearing a paddock blanket, depending on the weather.
In summary, our tip is that you decide individually on the basis of your horse and the existing conditions whether you need a blanket or not. We are of the opinion that it is good and sensible to have different blankets in order to be able to use them when needed. However, for the reasons mentioned above, we are not of the opinion that a healthy Icelandic horse should be permanently wear a rug.
What is your experience with blankets? Do you cover your Icelandic horses and if so, when and according to which criteria? By the way: If you would like to read more on the subject of blanketing, we recommend our articles Why do i need a Cooler Rug? and Does my Icelandic horse a need a rug in summer?