We investigated the main glycotopes expressed on the tissues of 44 animal species, including primates, nonprimate mammals, marsupials, birds, and a reptile. Paraffin-embedded tissue sections of kidney, heart, liver, pancreas, lung, brain and intestine of 24 domestic animal species were stained with seven fluorescent-labeled lectins. Testis sections of 20 African wild animal species were tested with the same lectins. Overall, three main immunofluorescence patterns were found in the vascular compartment. First, humans and Old World monkeys express genetically polymorphic ABH antigens and do not express αGal. Second, New World monkeys, other mammals, and marsupials do not express ABH antigens, but have large amounts of a genetically monomorphic αGal. Third, birds and reptiles do not express either ABH or αGal, but have monomorphic βGal, probably different from the lactosamine precursor of ABH and αGal. Epithelial cells producing exocrine secretions also expressed carbohydrate epitopes. The fluorescence patterns of the cells of the exocrine compartment are similar, but not identical, to those expressed in the vascular compartment. All the animals tested have some ABH and βGal in exocrine tissues, but New World monkeys and lower mammals are the only ones expressing αGal in exocrine tissues.