Ringworm/toothbrush culture question

Aku has been receiving ringworm treatment since mid-January (oral prescription and topical cream). The result of his first toothbrush culture (done 2 weeks ago) is negative but there's still a little black appearing on the very edge of his ear (it looks like the end stage of ringworm when it is finished flaking and just turns black and then dies off; and, even that black seems to be disappearing at a rapid pace). Needless to say, his owner is a bit confused - why was there a negative culture but still black areas appearing on his ear? Has anyone run into this before? I had no explanation for Aku's owner so I'm hoping someone here can help him. Thanks for your time.

Guys, I'm stumped...doesn't anyone have any ideas?

I wish I could help you. I don't know anything much but the basics on ringworm. I just ask the vet. LOL

Thank you anyways

If the ringworm culture came back negative then it probably is. Is it possible that the black around the ears is something separate from the ringworm. I went thru some major ringworm problems with my cat Simba and I didn't notice any black associated with it. Towards the end of the ringworm stage it would be scabby and flaking off as you mentioned, but never black.

Aku went back to the vets yesterday for his 2nd fungal culture (hopefully that one comes back negative too). The vet said the black is appearing because the oral meds are doing their job, and since there are no new lesions or hair loss, the ringworm has been contained and will not spread anymore. Apparently it's not uncommon for the black to appear like that - it's simply proof that the meds are working through his system, but it certainly doesn't mean that he's ringworm positive.

I don't have experience with this but I do wish you and Aku a ringworm free report.