Hormone response to training and competition in athletic horses.
BACKGROUND
It is recognised that the amount of psychological stress that an animal encounters determines the degree of response of the hypothalamic-pituitary-adrenal (HPA) axis. In human athletes, the added emotive stress of competition is an important element in the adrenal response. The aim of this study was to examine the effect of show-jumping as well as dressage on stress levels by comparing horses' stress response at a horse show compared to their familiar home.


METHODS
Fifty-one horses involved in competition were used. EDTA blood samples were collected before exercise, upon arrived to the schooling area (control), and k over a jump or dressage course. After sampling, plasma was separated and stored at -80 degrees C until determinations of cortisol and ACTH were performed. Fourteen healthy horses not involved in competition were used as control group.


RESULTS
Competition induced a significant increase in cortisol and ACTH responses in both, jumping and dressage horses and this effect was more apparent in dressage horses. When horses were most experienced, cortisol and ACTH responses were much lower.


CONCLUSIONS
This study shows that competition elicits a classic physiological stress response in horses and that different training programmes induce different responses. It suggests that horses involved in competition can provide a good model to study the exercise-induced stress response.
Cayado
P
P
Hospital SL., Madrid, Spain.
Muñoz-Escassi
B
B
Domínguez
C
C
Manley
W
W
Olabarri
B
B
Sánchez de la Muela
M
M
Castejon
F
F
Marañon
G
G
Vara
E
E
D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000818:Animals; D016022:Case-Control Studies; D006736:Horses / Q000097:blood / Q000502:physiology / Q000523:psychology; D006854:Hydrocortisone / Q000097:blood*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D013177:Sports; D013315:Stress, Psychological
D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone