The incidence and severity of gastric ulceration does not increase in overtrained Standardbred horses.
BACKGROUND
Gastric ulceration can be caused by different pathophysiological mechanisms including dietary factors, psychological stress and exercise. Overtraining is a medical syndrome in performance horses associated with altered hormone levels, altered feed intake, altered behaviour and decreased performance. These components might lead to a higher incidence of gastric ulceration in overtrained horses.


OBJECTIVE
To investigate whether the incidence of gastric ulceration is increased in overtrained compared to control horses.


METHODS
A longitudinal training study with twelve 1.5 years old Standardbred horses was performed on a treadmill for a total of 32 weeks. Training was divided into 4 periods: (1) acclimatisation (2) training (3) intensified training, and (4) detraining. In period 3, the horses were randomly divided into 2 groups: control (C) and intensified trained group (IT). At the end of each period, gastroscopy was performed in conscious horses after withholding feed for 12 h and water for 6 h using a 3.5 m video gastroendoscope. Lesion scores were assigned to areas of the stomach and graded 1-4. Logistic regression was used for statistical calculations.


RESULTS
Evaluation of the stomach revealed only minor changes (grades 1 or 2) on each occasion. There were no significant differences in gastric lesion scores between groups or periods. Most lesions (70%) were found around the minor curvature. After detraining no lesions (0%) were found in contrast to periods 1 (40%, P = 0.056), 2 (30%) and 3 (30%).


CONCLUSIONS
Experimentally-induced overtraining does not increase the incidence of gastric ulceration in normally fed Standardbred horses and detraining appears to reduce gastric ulceration.
Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, The Netherlands. e.roelfsema@uu.nl
E
E
De Graaf-Roelfsema
H A
HA
Keizer
I D
ID
Wijnberg
J H
JH
Van Der Kolk
D000818:Animals; D006734:Horse Diseases / Q000209:etiology / Q000473:pathology*; D006736:Horses; D008297:Male; D010805:Physical Conditioning, Animal / Q000502:physiology*; D013276:Stomach Ulcer / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D013315:Stress, Psychological