key words unitermos abstractImmunohistochemistry has become a practical and widely used tool for diagnosis in human pathology since the 70's. However, its application in veterinary diagnostic pathology has not been so common, especially due to the lack of specific antibodies. To overcome this drawback, antibodies which present cross reactivity with human and animal antigens have been applied. The purpose of the present study was to test the cross reactivity of some antibodies intended for the human pathology, which may be used in animal tissues, with the help of antigen retrieval and amplification systems. In the present study it was confirmed that many of the antibodies produced for use in human histopathology might be applied in veterinary pathology. Further studies are needed to increase the list of applicability of these antibodies to different animal species. It must be stressed that in this type of study some variables, such as clone of antibody, dilution, antigen retrieval method, and detection system, have to be evaluated. Lab • v. 41 • n. 4 • p. 263-70 • agosto 2005 a more accurate diagnosis. This fact has brought to the attention of veterinary pathologists the need to improve the application of immunohistochemistry in their daily routine, following the tendency of human diagnostic pathology. Immunohistochemistry