The few times I've been to some Eastern European countries, the street dogs were indeed not an issue. Just unsightly. They are actually useful as they get rid of carcasses of other dead animals (pigeons, rats, etc.) on the streets.

However, there are countries where the street dog population is way higher and attacks and rabies are a real problem. When these countries take action, they often mass-cull the dogs. In Bhutan's case, the dogs aren't going anywhere. The 100% number is simply not believable and soon there will be again a small, but manageable population.