Minimizing Harm in Possum Control Operations and Experiments in New Zealand

Pest control operations andexperimentation on sentient animals such as thebrushtail possum can cause unnecessary andavoidable suffering in the animal subjects.Minimizing animal suffering is an animalwelfare goal and can be used as a guide in thedesign and execution of animal experimentationand pest control operations.The public has little sympathy for the possum,which can cause widespread environmentaldamage, but does believe that control should beas painless as possible. Trapping and poisoningprovide only short-term solutions to the possumproblem and often involve methods that causesuffering. Intrusive experiments connected withthese methods of control and published in thelast 6 years are reviewed. Many of theexperiments do not attain the welfare standardsrequired by members of the public.Possums also act as vectors for bovinetuberculosis. While this is not as important inthe minds of the public as environmentaldegradation, as long as people wish to continueraising cattle, this disease needs to becontrolled.Immunocontraception is a humane means ofcontrolling possums with wide publicacceptance. The use of vaccines for cows and/orpossums would also cause far less sufferingthan present eradication operations. Researchinto these methods does require some intrusiveexperimentation. This can be reduced if liveanimals are not used for secondary antibodyharvesting, if adequate analgesia is provided,and if potential vaccines or contraceptives aretested under conditions that would beexperienced in the field.