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Winter coat shedding

Different stages of life also significantly influence coat development, a factor often underestimated. Horses below 5 and over 20 years of age tend to begin shedding their winter coats earlier, develop thicker fur, and retain it longer into spring. This phenomenon is related to the available energy for “heating.” Young horses allocate energy for growth (and playful activities), while older horses often experience compromised fermentation processes in the large intestine, leading to malabsorption syndrome—a condition where nutrients aren’t adequately absorbed from food pulp.

The horse’s large intestine is a major heat generator. Similar to the heat-intensive composting process or decay in a dung heap, the utilisation of plant fibres by microorganisms (fermentation) releases energy for the horse.

Anyone who has ever plunged their hand into a compost heap during winter can appreciate the substantial heat generated. Consequently, the large intestine contributes to the horse’s warmth. Moreover, the liver produces energy as a byproduct of its diverse metabolic functions. In cases where a horse is provided with limited hay portions, substantial gaps between meals (often 2-3 meals per day with extended breaks, especially overnight), or experiences dental issues (young horses aged 2 to 5 due to tooth changes, and older horses beyond 20 due to age-related dental and jaw joint problems), or when wind and weather protection isn’t sufficient for all horses to find shelter, the internal “heating” might not suffice to meet the demand during frigid weather. Such horses are compelled to develop a thicker winter coat that they retain for a longer duration compared to their stablemates in neighbouring stalls, where hay is available ad libitum and solid wind and weather protection is ensured.

© Adobe Stock / Rita Kochmarjova

For many horses diagnosed with “Cushing’s disease” (PPID) in spring, the condition may often be attributed to either normal, healthy horses with substantial winter coats or problems originating from erroneous human feeding or management practices. Subjecting the horse’s body to medication to suppress potentially non-existent symptoms is not only futile but can also be detrimental. Therefore, exercising caution and reserve in labelling a horse with “PPID” is essential, and resorting to drastic measures should only occur when the horse is genuinely unwell, and all other interventions fail to yield improvement.