Western toad with blood leaking from top of heat

[cwebster]

MrToad had hypocalcemia as a newly morphed critter and has been treated with calcium and vit D three times per week for eight years. He has required hand feeding and loves daily baths in mineral water. He has always been slow and gimpy. Two days ago, he began leaking a small amount of blood from a tiny hole in the top of his head. Vet I consulted had no idea what is going on. He is still alert and moving around but I am very worried about him. There is nothing he can cut himself on in his tank. I do not let crickets run loose in his tank. Anyone ever encountered such a thing in a toad or frog? Should I get the vet to do a culture and use antibiotics drops on him?

here are photos.