Levamisole can induce conditioned taste aversion in foxes

Conditioned Taste Aversion (CTA) develops when animals associate the taste of a particular food with illness and subsequently avoid consuming that food. We evaluated the potential of two chemicals, thiabendazole and levamisole hydrochloride, to induce CTA to meat in captive foxes ( Vulpes vulpes ). Foxes were presented for 45 min with thiabendazole or levamisole-treated meat (treatment group) or with untreated meat (control group). In subsequent tests, carried out at 3-week intervals, we tested whether foxes had established an aversion to untreated meat. One or two doses of thiabendazole induced CTA to the test meat in 3 out of 4 foxes. All foxes that had consumed a single portion of levamisole-treated meat avoided eating untreated test meat for the following seven post-treatment tests. The potential of using levamisole-induced CTA as a non-lethal method of manipulating the behaviour of predators is discussed.