I know primarily about guide dogs in the US, but of course they exist in plenty of other countries. They originated in Germany, and I know of guide dog schools in Canada, the UK, Israel, Korea, and other countries. GDF actually uses training philosophies that are more British than American, but I’m not sure what that means. I’ve heard there was a guide dog in Singapore, but it was trained in the US, and its reception in Singapore was lukewarm at best, even by the blind community. But in several countries, guide dogs are probably about as common as they are here.
Sometimes there are some issues with accessing island nations, who are keen to prevent the spread of rabies. They have a strict quarantine system, which isn’t so great for people who need to travel with their guide dogs. There are procedures for people traveling to some of these countries where they can send in blood samples from their dogs ahead of time to ensure they’re free of rabies.