Conditioned taste aversion, CTA

,,Conditioned taste aversion” is used to estimate if compound produce discomfort to animals.

When animal taste new diet or drinking water with foreign taste for example sweet taste and immediately after experience discomfort (conditioned stimulus). The distress is induced by injecting known compound that causes discomfort immediately after it has drunken the water or eaten the diet (unconditioned stimulus). The animal connects the discomfort to the foreign taste and the day after, the animal avoids the new foreign taste and rather chooses another options.
It can be difficult to estimate if small rodents experience discomfort. This model has the benefit of being able to detect minor discomfort by measuring food or drinking water intake.