So my Drake has been having lots of issues walking so I went to the vet and they prescribed him clindamycin. I also give him crushed vitamin B complex in his water every day. After a week of the meds he's still the same and just this morning I noticed his beak looks very pale and has areas that look white. He is a mallard so his beak should look yellow. Anyone know what this could mean or whats causing the beak issue now?