Although novel forms of oxytocin with a single amino acid substitution, which may affect overall antibody binding affinity, have been described in some primates (Lee AG et al., 2011), the oxytocin molecule sequence does not vary between most mammalian species making this kit species-independent. Cited sample origins include baboon, degu, dog, elephant, human, mouse, pig, rabbit, rat, rhesus monkey, seal, tamarin, and vole. Please note that a problem may arise when working with rabbit sera. This is not due to the oxytocin itself but because the antibody used in this kit is an anti-rabbit IgG, which may cause high signal background.