My struvite girl showed a sensitivity to carageenan, too. It wasn't until I stopped giving her foods with this ingredient that the regurgitation stopped completely. Oddly enough, many of the store brands don't seem to contain carrageenan, but many of the "high end" foods do. It's frustrating, as I would like to get all three cats off carrageenan completely, but.....I am reluctant to rely on only one or two brands, and cannot bring myself to feed foods that contain dyes and artificial things, and wheat gluten and....well you know the drill..