The World Health Organization states that envenomation is responsible for a high number of deaths per year, especially in equatorial areas. The only effective specific treatment is the use of hyperimmune serum (antivenom). In Brazil, Crioula breed horses are used for antivenom production, with great importance in the maintenance of public health programs. A strict biochemical and metabolic control is required to attain specificity in antiserum. Inorganic elements represent only a small fraction of whole blood. Nonetheless, they play important roles in mammalian metabolism, being responsible for controlling enzymatic reactions, respiratory and cardiac functions and ageing. In this work, whole blood samples from Crioula breed horses were analyzed by EDXRF technique. The reference interval values were determined for the elements Na (1955-2013 mu g g(-1)), Mg (51-75 mu g g(-1)), P (523-555 mu g g(-1)), S (1628-1730 mu g g(-1)), Cl (2388-2574 mu g g(-1)), K (1649-1852 mu g g(-1)), Ca (202-213 mu g g(-1)), Cu (4.1-4.5 mu g g(-1)) and Zn (2.4-2.8 mu g g(-1)) and a comparative study with NAA results was outlined. The samples were obtained from Instituto Butantan. Both techniques showed to be appropriate for whole blood sample analyses and offer a new perspective in Veterinary Medicine.