Okay dog walking is a booming business in the First World apparently some people value it so much they spend a fortune trying to provide care for their dogs. Check out this article about a doctor who quit her job to become a dog sitter. I just wish she could have made the decision a decade sooner so that one of the hundreds of students rejected from the medical school admission service could have had her position and would be contributing to help alleviate the physician shortage in the US.
In contrast, one of the most prominent problems in developing countries is Malaria. Malaria has had a cure for decades but still it affects an estimated 300-600 million people each year. It is the largest killer of children killing one child every 30 seconds, about 3000 children every day.
Over one million people die from malaria each year, mostly children under five years of age, with 90 per cent of malaria cases occurring in Sub-Saharan Africa. In summary, developing countries have 99 problems and a dog walker is not one of them.