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 five to seven post-treatment tests. The potential of using levamisole- induced CTA as a non-lethal method of manipulating the behaviour of predators is discussed.