**6. Conclusions**

This review presents new aspects toward understanding neuroendocrine regulation of equine stress, and its influences on the physiological and pathophysiological processes. Horse management, in essence, is more frequently confirmed by external and internal stress factors, in comparison to other domestic animals.

### *Equine Stress: Neuroendocrine Physiology and Pathophysiology DOI: http://dx.doi.org/10.5772/intechopen.105045*

In the last few decades, the initial concepts of stress have been revised. New studies have expanded the basis of stress responses to signals from various sensory receptors, through complex interactions of at least three systems that are activated in a time sequence: the locus coeruleus-norepinephrine (LC-NE)-sympathetic system, the HPA axis, and the endogenous opioid system. The interconnection of these systems provides control of norepinephrine, epinephrine, and cortisol release, but also other stress mediators, such as corticotropin-releasing hormone, adrenocorticotropin, vasopressin, β-endorphin, dopamine, neuropeptide Y, serotonin, oxytocin, cytokines (IL-1β, IL-6), pituitary adenylate cyclase-activating polypeptide, FMRFamide-related peptides (FaRPs), prolactin-releasing peptide (PrRP), and others. Linked into this interconnection network are other organ systems affected in one or several stages of the stress response. Commonly, these reactions in the horse are related to short-term stress responses leading to mobilization of the body's reserves in a process of constant flow around the homeostatic point. In situations of allostatic overload, a dynamic change from physiological to pathological response can be expected in horses, with the induction of primarily stomach ulcers, paralytic ileus, colitis, and pleuropneumonia. The change from equine physiological to pathological stress response depends not only on whether the stress is acute or chronic but also on the physical characteristics of the stress signals (intensity), as well as on the initial hormone levels, which in turn depend on various factors, including photoperiod sensitivity.

The development of stress-related diseases in horses dictates how long the interaction of sanogenesis with pathogenic factors will last. These diseases can often be prevented or controlled by keeping risk factors minimal, and by assessing stress levels using a variety of testing techniques. Regardless of the nature of the stimulus, the equine stress response is an effective and highly conservative set of interconnected relationships designed to maintain physiological integrity even in the most challenging circumstances. It activates numerous neural and hormonal networks to optimize metabolic, cardiovascular, respiratory, locomotory, and immunological functions.
