De Graaf-Roelfsema E, Keizer H A, Wijnberg I D, Van Der Kolk J H
Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
Equine Vet J Suppl. 2010 Nov(38):58-61. doi: 10.1111/j.2042-3306.2010.00268.x.
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.
To investigate whether the incidence of gastric ulceration is increased in overtrained compared to control horses.
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.
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%).
Experimentally-induced overtraining does not increase the incidence of gastric ulceration in normally fed Standardbred horses and detraining appears to reduce gastric ulceration.
