First, happy birthday, Gizmo!!!
You definitely need to see if this is fungal or bacterial. There are these antifungal lotions you can use if it's fungal. I recently had to get some for my Shelby-Dale. If it IS bacterial and an infection, you need to get some antibiotics asap..could spread either way so I would definitely get to the vet.
Have fun at the beach! TIP-try utilizing that natural salt water on his belly tomorrow. It does an ailing body good
