Hello Caroline: Congratulations on your little rescued friend. How nice! A crusty beak could be caused by common bird mites called Knemidocoptes (scaly leg and face mites). It's easy for your avian veterinarian to treat but can get pretty severe if left untreated. The crustiness of the beak is usually white to pale yellowish-brownish and has tiny holes in the crust (like a coral reef type look). You can also see these crusts sometimes on their legs and feet and around their eyes. As far as his weight/size, he may have internal parasites which are keeping him from growing. That's another reason to get him to an avian veterinarian. The vet will perform a physical exam, a fecal analysis (looking for parasites), possibly a microscopic exam of the crusts on his beak to look for mites (sometimes this isn't necessary) and an overall exam of the bird. The vet will also discuss diet and housing with you, as well as any other questions you have about taking care of your little rescued bird. I would recommend trying to add more variety to his diet than just seeds. See if he will eat parakeet pellets, cooked rice, cooked pasta, grain breads (i.e. tiny pieces of cocktail rye bread, etc.), lettuce, fruits, etc. It's good for birds to eat a variety of foods. If a bird eats only seeds, they can have liver issues as they start to grow. I'm not suggesting you remove his seeds because some birds don't like to try new foods very eagerly. You may have to experiment to find out what he'll eat. Be aware that when you put something new into his cage, he may be afraid of it (like a piece of bread). Give him time to get used to seeing new foods in his cage and pretty soon he'll probably start tasting them. I could type 50 screens on proper avian diets but your best resource will be your vet when you take the bird for an exam. If you need help finding an avian vet, here's a web site to assist you:
http://aav.org/vet-lookup/. Best wishes.
The best answer to any question regarding a sick pet will come from your own veterinarian, however, I am happy to provide information based on my experience.
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