Okay, to start off, I bought a male and female parakeet about 5 years ago, maybe more, well, the female flew out the door and our male died this winter when the cage door got left open, and our indoor cat got him. Before he died though, he developed crusts on both sides of his beak, and it looked like his beak was starting to crumble or chip off, especially the bottom one. We got 2 parakeets the day after he died, (another male and female) and this male is getting the same thing! They eat standard parakeet food, millet, have clean water and papers, and work off a cuttle bone. Oh, one other symptom is sneezing, and our previous one got lumps/crusts on his toes too. What could this be? He seems fine otherwise. When he sneezes, I just put him on the porch in the fresh air, and that seems to cure it.