The Immune System of the Older Horse

Given the growing number of older horses worldwide, we are now facing new challenges with the paradox of an old horse population with increased longevity and the potential of increased age-associated diseases. It has been appreciated for many years that the immune system undergoes gradual deterioration with age, referred to as immunosenescence. While aged horses have pre-existing humoral immune responses, these levels may not be sufficient enough to sustain protection in the face of an infectious challenge. Therefore, periodic vaccination is important, in order to maintain a protective level of immunity by preserving memory responses. Nutritional interventions are practical, cost-effective approaches to mitigating age-related breakdown in immune function. Natural dietary compounds found in a variety of plants, roots, fruits, vegetables, nuts and seeds are promising candidates for helping to combat the effects of an aging immune system, with a broad biological activity.