Amphibian species such as frogs, toads, and salamanders are commonly used in laboratory animal research settings, but there is no objective means to assess the presence and
severity of pain in amphibians, especially since they do not exhibit any facial
expression. However, research studies have shown that amphibians are able and motivated
to learn to avoid noxious stimuli.
Some exotic animal clinicians use
nonspecific clinical signs such as decrease in avoidance movement (e.g., when
approached by a handler) or decrease in appetite as indicators of pain in these
animals.
