Fluid therapy for mature cattle differs from that for calves because the common conditions that result in dehydration and the metabolic derangements that accompany these conditions are different. The veterinarian needs to know which problem exists, what to administer to correct the problem, in what quantity, by what route, and at what rate. Mature cattle more frequently suffer from alkalosis; therefore, acidifying solutions containing K⁺ and Cl⁻ in concentrations greater than that of plasma are frequently indicated. The rumen provides a large-capacity reservoir into which oral rehydration solutions may be administered, which can save time and money.