A man carries his dog to be vaccinated.

Vaccinating dogs is hazardous at the best of times, but when the dogs in question are semi-feral, a whole new level of skill and speed is needed. One must approach the dog from behind, syringe in hand, and the vaccination needs to be completed in a single-handed rapid action. If you do it well, the dog often doesn’t even know s/he has been vaccinated, but get it slightly wrong, and you may have a snapping jaw aimed at your hand.

Incredibly, by the end of my three days working with the Lincoln Park Zoo–sponsored rabies vaccination team, hundreds of dogs had been vaccinated yet not one team member had been bitten.

Follow up:

Our team was working in a district west of Serengeti National Park, visiting villages near the bustling town of Bunda, which lies on the eastern edge of Africa’s largest body of water, Lake Victoria. These villages are particularly important for the vaccination program, as they are on the fringes of the park, where contact between domestic and wild animals does occur. With every contact there is a risk that a dangerous infection may “spill-over” to the wild and cause a population crash, such as when rabies caused the local extinction of African wild dogs in Serengeti National Park in the early 90s.

Indeed, along with habitat loss and illegal hunting, infectious diseases are increasingly implicated as one of the major conservation issues threatening the existence of endangered wildlife species.

The aim, therefore, of the Lincoln Park Zoo–vaccination program is to prevent rabies outbreaks (as well as distemper and parvovirus infections) in endangered wild animal species while also preventing this terrifying disease from occurring in humans. Since rabies is estimated to cause 1,500 human deaths each year in Tanzania alone, this preventable disease is not just a concern to conservationists but also to those working in public health.

So how do you control an infection like rabies? The key is to eliminate the disease in the reservoir host, namely domestic dogs; as a result, the disease will be eliminated in wildlife and humans too. Epidemiological modeling calculations have shown that we must vaccinate at least 70 percent of the local dog population (up to 50,000 dogs) each and every year in order to do this.

That’s a lot of dogs! Therefore, at each village it’s critical that as many dogs are brought to be vaccinated as possible. To make sure the villagers are aware of the team’s visit, a vehicle with a loudspeaker is sent the day before to make an announcement. Posters are also placed on walls.

Posters inform villagers about the impending vaccination.

Then the following day, as announced, the team sets up a mobile vaccination clinic in the center of the village and awaits the arrival of villagers and their pets.

Villagers and dogs en route to the vaccination clinic.

The dogs, which are generally mixed-breed, begin arriving with their owners soon after 8 a.m. Usually they are led, or rather dragged, by a piece of rope tied around their necks. Newborn puppies are often carried in buckets by children.

A puppy being carried to the vaccination site.

Each dog is registered, receiving a vaccination card and identifying yellow collar, and then it’s time for the moment of truth. The vaccinators have injected so many dogs that they’re experts. From the dogs’ perspective, the effect is rather like having your pocket picked—they’re usually only aware something has happened once it is all over.

Practiced hands have become skilled at quick vaccinations.

Vaccination days generally start rather slowly, making one wonder whether the announcements have worked. But there is never a need to worry. Typically by 11a.m. the queue of reluctant dogs snakes out of sight into neighbouring fields and the vaccinators know it is going to be another long, hot day.

But they are fortified by the knowledge that their efforts are effective. Since the vaccination program began in 2003 there has been resurgence in the population of African wild dogs. There has also been a dramatic reduction in rabies in humans and wildlife in and around the Serengeti ecosystem. In the end, everyone on the team is acutely aware just how important this hot work is to humans and wildlife alike.

Felix Lankester