The group's free services are in high demand, so much so that Dr. King recently sold her animal hospital in Wisconsin to take on World Vets as a full-time endeavor.
She says the week-long trips to foreign countries fill up quickly with about half a dozen assistants. Volunteers train for duties – such as giving shots – on location.
"A lot of people's expectation is that they aren't going to have an important job, or [be] given a token volunteer job," says King. "But what they love is they really do have something important to do."
Those taking part in volunteer vacations can expect to work more than they play. They may toil long hours with usually only a day or two allotted for sightseeing. But for many, that's exactly why they signed up for this kind of trip.
Still, says Emma Clifford, founder of Animal Balance, which organizes high-volume sterilization campaigns in the Dominican Republic and the Galápagos Islands, it can be a bit of a shock in the beginning. For one thing, volunteers are being asked to work hard in a job they may have never done before. And a typical work day can start at 7:30 a.m. and not end until 6 p.m. or later.
"It can be a little bit scary for some people," says Ms. Clifford, "but normally by Day Three or Four they love it."
Each Animal Balance project has about seven nonveterinary volunteers who keep a watchful eye on recovering animals, clip nails, clean ears, as well as deal directly with pet owners.