He already had bloodwork and nothing showed up, in the skin scrape they just detected bacteria and in the skin biopsy they caught the staphyloccocus aureus. No fungi in any of those.
He was also seen at a vet teaching hospital by both students and doctors and most of them agreed on mange and one has been studying his case closely to no avail.
I think if you are that concerned you need to contact your vet and if you feel the bleeding is excessive you need to have him seen by an emergency vet this evening. This definitely needs to be seen by vet to be sure any drainage from the surgery site is normal.
Good Luck
Dr Dawn