Blood and biochemical profiles of animals can be used to evaluate the physiological state of an individual and relate it to that individual’s health. In many countries, water buffaloes are currently evaluated using blood parameters from other bovine species. To accurately interpret the biochemical results from individual animals, species-specific reference ranges should be established. One hundred and twenty-eight water buffaloes, without clinical signs of disease and of different ages, were analyzed, and reference intervals were calculated (95% CI; p < 0.05). The data were analyzed according to three age groups (calves, young animals, and adults) and the infection status (infected or uninfected with Trypanosoma spp.). All the biochemical values of total serum proteins, aspartate aminotransferase, gamma globulin, urea nitrogen, calcium, and phosphorus were included; these are parameters that are generally affected by parasites or by infection with hemotropic agents. Natural infection with Trypanosoma spp. gave rise to differences (p < 0.05) in terms of increased calcium and decreased total protein, alkaline phosphatase, and aspartate aminotransferase. Thus, it can be inferred that the infection follows a chronic course in the affected animals, in this case, young animals or young animals.