Horses immunized with E. coli K235 L + O(m) produce antibodies that can both precipitate and neutralize colicine K and also neutralize a different type, colicine I.
Unlike rabbits, horses generate antibodies that target colominic acid, a polysaccharide that contains sialic acid.
This difference in immune response highlights horses' unique ability to react to certain bacterial components compared to other animals like rabbits.