Not only World War II started in 1939 in Europe. Another disturbing event that went on until 1980s was epidemic of rabies. The disease was carried by red foxes, and it spread onto domestic animals. Rabies is almost always fatal, also for humans (unless a vaccine is provided).

When the disease reached Switzerland in 1967, multiple solutions were tried and most of them failed. Authorities attempted to shoot, trap, or poison the foxes, but it turned out ineffective. Attempts were made to capture the animals, and vaccinate them before releasing back in the wild, but the cost and scale of operation proved to be uneconomical.

New idea emerged in the United States: the Vac-Trap. It was a spring-loaded mechanism with hidden syringe that was supposed to jab the animal when it stepped on a foot pad trigger. Something like a land mine, but with needles and vaccines. It kind of worked, but posed a threat for humans. Wilderness lovers were sometimes stabbed with Vac-Trap as well.

Chicken heads from air

Many trials with vaccine laden edible bait proved unsuccessful: eggs, dog biscuits, deep-fried cornmeal with milk, sausages. Foxes like the eggs so much that they store them away for later, and meanwhile the vaccine dies. One bait turned out to be perfect: chicken heads. I don’t want to know how scientists conceived this idea, but soon it rained disembodied chicken heads in Swiss forests. Helicopter air drops were used, but only in remote areas. In accessible areas firewalls of thousands of chicken heads were created by teams on foot.

Switzerland rabies free today

After four years more than 50,000 chicken heads with vaccine capsules were distributed and rabies was under control. Soon other countries devised better baits, like special fish tablets manufactured in Germany. After distributing more than 150,000 chicken heads, Switzerland finally switched to other successful baits in 1991.

Fact source:

New Scientist / 13 January 1983

Top image credit:

A dog with rabies engraving (Credit: Wellcome Library, London. Wellcome Images / CC BY 4.0)