Abstract: A palatable antimicrobial drug concentrate comprising: (a) a sulfonamide and/or sulfonamide salt in aqueous solution; (b) a 2,4-diaminopyrimidine in stable suspension within said solution; and (c) a suspending agent. The invention has a long room temperature shelf life and is sufficiently stable to be administered via the drinking water of animals.

Abstract: A dry solid mixture of a hydroxypolycarboxylic acid and a cephalosporin where the hydroxypolycarboxylic acid of the formula ##STR1## where x and y are 0 or 1 and z is 0 to 3, in the weight ration of hydroxypolycarboxylic acid to cephalosporin of at least 1.8. The invention comprises a solution made from the dry solid mixture and a process of treating animals with cephalosporin by including the solution in the water fed to the animals so that the animals can ingest the cephalosporin. A particularly preferred mixture is one of citric acid and cephalexin.