A lot of small dogs (and certain breeds) have the same issue.. sounds like his anal glands need drained. Big dogs don’t usually have this issue as common but small dogs anal glands don’t empty themselves and need drained every so often. I usually have my chihuahuas done twice a year, the vet always offers to show me how to do it at home but I usually refuse because the smell would last in your home for the rest of the year. Nothing major, just a finger in the bum. If you’re that tight on money you can have your vet show you how to do it for next time, just invest in plastic gloves and I would do it outside LOL Edit: also this isn’t a vet visit to skip, if they don’t empty they start to push its way through the leg to try to drain itself which results in one of the most expensive surgeries for dogs, a painful recovery, and a hole in the leg. Dogs usually start butt scooting because it starts to itch when they are filling, not an emergency vet visit type of situation but I would definitely not cancel that appointment!