But it’s not just variations in temperature that prompt coat change – in particular the length of daylight plays a key role too. The pineal gland is of importance here. One of its functions is synthesis of the sleep hormone melatonin as this is responsible for controlling the entire coat change process depending on daylight length. Particularly when temperatures become extremely high or low, the equine organism will respond by either increasing or reducing hair density and length. This also explains for example why stabled horses generally have a shorter and lighter coat than others that are kept in an open stable and thus have denser and longer hair. After the winter solstice in the middle of December with days becoming longer again, the equine organism then begins – unnoticed by the owner – with synthesis of the summer coat in the skin. This gradual process takes place more slowly than the coat change occurring in autumn, as it is first the top coat that is shed little by little, until it is then the turn of the dense underwool. By the end of June, when days are getting shorter again, the horse has already begun to change his coat for winter. This cannot however be seen until temperatures fall and the animal’s light summer coat makes way for his warm winter one.
Offer targeted support to weaker horses early on
Coat change can present an enormous challenge, above all for older or sick horses, and every owner undoubtedly wishes to help here. If a horse has a chronic illness, the increased demand on the metabolism can weaken the immune system to such an extent that the animal responds via the lungs, resulting in coughing. Should a horse not lose his coat at all or only in certain spots, this might not just be due to a lack of minerals, but also a metabolic disease, which should then be investigated by a veterinarian without fail. If coat change is severely delayed in older horses, owners can use clippers in spring to make sure that their animals do not suffer from the higher temperatures, so burdening the circulation. In particular horses under major metabolic stress (competition horses, broodmares and colts) may prove to be deficient in nutrients despite being fed an appropriate diet, which may then lead to problems. Secondary diseases such as bronchitis, eczema, allergies or joint complaints are not uncommon here.
Prepare foals well for coat change from the start
For a foal born in spring the first coat change represents a special hurdle as it often coincides with weaning and separation from the mother. This also means that his customary diet, her milk, is no longer available. Further stress comes about with the move to a foal group, so making additional demands on nutrient requirements.
What does coat change mean for the equine organism?
When nights get colder, it is time to increase the amount of feed as there is a significant rise in the energy requirement in the basal metabolic rate. If a horse is to be able to make the coat required, he needs an additional intake of nutrients that can hardly be covered by the basic feed. Horses often appear listless and lethargic during coat change. It should therefore be considered very carefully how much work and effort can be expected of the animal at this time. It is possible here to kill two birds with one stone by adding oils such as linseed and hemp, or preferably fish oil, which is not only rich in omega-3 fatty acids but also easy to digest. Although the energy density of oils is the highest among all energy carriers, this compensates on the one hand for the increased energy requirement. On the other hand, anti-inflammatory effects are attributed to the unsaturated fatty acids contained in oils, so possibly making a valuable contribution to supporting the immune system. When seasons change, the constant demand of thermoregulation due to the fluctuating temperatures is particularly stressful for the immune system and circulation. At this time it is also advisable to slightly step up use of the curry comb to counteract itching caused by the regrowth or shedding of hairs.
Nutrients, energy and other helpful aids
In addition to the increased energy requirement at coat change (around 1.5 times higher than normal), there is also a sharp rise in the need for bulk and trace elements. First and foremost is the need for zinc as it is vital for the formation of new skin cells and hair follicles. Keratin is the most important structural protein for the coat, and the enzymes responsible for making it require zinc if they are to function smoothly and without any defects. Copper and the B complex vitamins likewise play a key role in hair synthesis and the stimulation of cell growth. Coat change is so burdensome for horses that it is advisable at such times to refrain from subjecting them to any further stress and so put off vaccinations and worming treatments until a later date.
Autor : Dr Fritz Caroline