Abstract
BACKGROUND: Neoplasia may cause hypoglycemia in different species including the horse, but hypoglycemia has not previously been reported in the horse associated with gastrointestinal stromal tumours. CASE PRESENTATION: A case of a gastrointestinal stromal tumour in a Fjord pony with severe recurrent hypoglycemia is presented. The mechanism causing the hypoglycemia was not established. CONCLUSION: This case indicates that a gastrointestinal stromal tumour may cause hypoglycemia also in the horse.