Stress, illnesses and its consequences

The stress; this word comes up often! What is it exactly?
And why does a “stressed” horse present physical problems and in the long term a reduction in resistance?
The stressed horse is not just an agitated or anxious animal, but much more than that.
Stress can be defined as the sum of biological reactions to aggression. These attacks can be external, perceived by the senses, internal (pain) or psychological (anxiety, tensions, worries).
There are two types of stress:
1) physical stress (work, injuries, vaccinations)
2) psychological stress (anxiety, withdrawal, frequent transport, change of environment, confinement, etc.).
Just as in humans, in horses there is an intimate relationship between body and mind. This will be particularly explicit in the face of a brutal conflict situation.
The horse becomes anxious, even fearful (psychological stress), its reactions are then as follows:
*bulging eyes, increased respiratory and heart rates as well as vascular tension;
*slowing down of digestive functions (physical, orthosympathetic stress);
*maximum alert situation, flight reflex.
When the situation returns to normal, the organism (parasympathetic) regains its level of balance: return to a normal respiratory and heart rate, etc. The physiological mechanism allows the body to maintain homeostasis. If the horse is stressed too often, or for too long, homeostasis will be permanently disrupted with the consequence: immune disorders, illnesses, injuries and exhaustion.

Physical consequences of stress
Brain level:
*limbic system: center of emotions, behavior and memory;
*hypothalamus: regulation of homeostasis, in close relation with:
*pituitary: humoral response.
As soon as the horse experiences psychological stress, the limbic system sends signals to the hypothalamus, which in turn stimulates the pituitary gland and the autonomic nervous system (see diagram). In the event of continuous stress, the latter causes functional disorders within different organs, for example gastric and intestinal ulcers, cardiac, renal or pulmonary disorders, muscle contractures, etc.
The pituitary gland is capable of two kinds of reactions:
*nervous reaction: release of ADH (vasopressin) which regulates the hydro-electrolytic balance in the kidneys;
*humoral (vascular) reaction particularly important in stressful situations: the pituitary gland releases ACTH which, by stimulation of the adrenal cortex, will lead to the production of corticosteroids (“stress hormones”).
There are 2 types of corticosteroids:
1) mineralo-corticoids (aldosterone) which regulate mineral metabolism (Na+, K+, Cl-) and blood pressure;
2) glucocorticoids: the most important in the event of a stress reaction is cortisol, the production of which then increases significantly. Cortisol:
*slows the absorption of glucose by cells and increases the level of circulating glucose. It has a major role in the regulation of carbohydrate metabolism;
*it also slows down the absorption of amino acids by muscle cells;
*the increase in cortisol has a depressant effect on immunocompetent cells (lymphocytes, leukocytes) leading to a reduction in the body's resistance to inflammation and infection.
Prolonged stress leads to permanent humoral “mobilization”, with the consequence: hypertension, gastric and intestinal ulcers, digestive, cardiac, skin, pulmonary disorders, susceptibility to infections, decline in condition, appetite, etc.
The resulting reduction in resistance being a stress in itself, the situation is self-perpetuating (see diagram)

How can we break this vicious circle and limit its consequences?
The lifestyle and use of the horse will have to be taken into consideration.
Sport horses must constantly receive antioxidants ( D-Tox ) and probiotics ( Biotics ), as well as courses of Equi'drink Immunotonic .
In a systematic way we will consider:
*after antibiotic treatment, vaccines, dewormers: administer probiotics and drain the liver and kidneys; ( Equi’drink Drainage );
*after a move, a change of stable or owner: give the horse time to get used to its new environment; he is much more attached to his habits than you might think;
*for horses that travel a lot or for a long time, it will be necessary to provide rest periods in order to break the vicious circle of stress;
*in case of loss of appetite and loss of energy, but absence of fever: consider the benefit of draining the liver and kidneys associated with the provision of a probiotic or a course of Equi'drink Immunotonic ;
*if the horse yawns often, head down, he may be suffering from gastric acidity: then try a treatment of Thrive , the clay will absorb the excess acidity. If the results are insufficient, consider GastriAid (see also Digestion - gastric ulcers).

Always observe your horse carefully: every change in his attitudes, behavior, in the appearance of his hair, in his appetite, etc. should demand your attention. If in doubt, consult your veterinarian.