The causal link between impact vibration and injury remains controversial. The ability of the foot/limb to accommodate impact forces is dependent (in part) on the amplitude, frequency, duration and direction of oscillations it experiences as a result of the foot-ground collision. The requirement to perform conflicting functions at impact may leave the foot (and limb) vulnerable to mechanical insult. Force transmission demands high stiffness and low damping - features that reduce vibration attenuation. So how do impact vibrations compare across ungulates and what is the influence of effective foot mass? We hypothesised that frequency of impact vibrations are kept at a constant level with increasing size and that effective foot mass and vibration frequency would have a significantly negative correlation. Using force platforms we measured the frequency content of impact forces in ten ungulate species (1-6 individuals/species) spanning two orders of magnitude (ranging from an 18kg blackbuck antelope to a 1058kg giraffe) at normal walking and trotting speeds. Frequency of impact vibration appears to be invariant of body mass. In general, the impact force experienced by the hindlimb contained a larger proportion of high frequency vibrations (50-100Hz) than the forelimb; this finding runs counter to a supposedly lower incidence of injury in the hindlimb. Horizontal oscillations were consistently high in the horse. Characterising the mechanical consequences of foot impact has significant implications for animal welfare and further investigation may provide insight into mechanisms to prevent injury.