STRONGID Paste is an equine dewormer containing pyrantel, a compound from the tetrahydropyrimidine class. STRONGID Paste is approved for the removal and control of mature infections of large strongyles (Strongylus vulgaris, S. edentatus, S. equinus); pinworms (Oxyuris equi); large roundworms (Parascaris equorum); and small strongyles in horses and ponies.