MobyKirby

Hi, I am new to this forum, but was hoping to get some advice. My 3 year old male budgie Moby (indoor cage) has lost a lot of his feathers above the crest and his skin looks red, almost bloody. A few days ago he had brown discharge on the feathers, but now his feathers look chewed away and have black specks on the end of them (I hope I can post a photo) and there seems to be clear puss. I only seem to be able to find images of scaly face mite, but only his feathers are affected around the beak. He had a bad day yesterday, not eating his favourite treats, sitting very low on perch. I thought he had an infection so have been treating him with antibiotic for 4 days. It was not until yesterday I realized he may have mites. So I raced to get Avimec and have treated him with it, today he has improved, is eating again and more vocal, so maybe the mites made him unwell? He is still not 100%, but fact that he has improved makes me hopeful for recovery. I just took my other budgie to the vet last week because she has a bare tummy spot with black goo (which I thought were dried droppings)on feathers, but vet did not even mention she might have mites? Seems she may have a tumour or hernia, vet could not tell. I feel that they both have been infected with mite. I decided to research the topic, but people mainly describe scaly face mite. Any help would be appreciated!