The main three remedies for gastric & duodenal ulcers in horses, are the first 3 remedies - the following remedies should be given, depending on specific symptoms.
Depending on specific issues:-
Atropinum Compositum, ad us. vet. Ampoules - in the event of gastro-intestinal spasms.
Chelidonium Homaccord Ampoules - for detoxification of the liver.
Spascupreel Ampoules - in the event of gastro-intestinal spasms.