Abstract:
The present study aimed to develop a method for testing pain-related behaviour induced by formalin in the
Speke’s hingeback tortoise (Kinixys spekii). These animals retract their head and limbs into their shell when
approached, making behavioural testing almost impossible. It was found that suspending the animals in the
air, facing away from the observer, made the animals keep their limbs out of the shell. Subcutaneous injection
of formalin induced easily identifiable and quantifiable behaviours that lasted for 20 minutes. Contrary
to the biphasic effect of formalin observed in rats and mice, the response in tortoises was monophasic. The
suspended formalin test may be useful for studying nociceptive mechanisms in tortoises, which in turn will
be important for a further understanding of the nociceptive system in reptiles as well as in mammals.
