Abstract: Apparatus is described for effecting an objective measurement of the intensity of pain induced by a nociceptive irritation of one of the paws of a laboratory animal. The degree of pain is manifested by the animal's repetitively lifting the injured (i.e., test) paw. The test paw is normally in contact with a pair of adjacent conductors of a planar conductor array forming the floor of the animal's cage. Such paw is provided with an electroconductive coating on its plantar surface, so that when such paw is irritated each resultant lifting of the paw from the surface breaks the contact between the bus bars. The total time over which the conductively adapted test paw completes the circuit between the bus bars during a prescribed measurement interval is recorded, together with the total number of disconnections of the paw-base contact over such interval.