Here is an article on parasites you can read, outdoor birds are more likely to get them, then an indoor bird 
They don't need any regular medication that I know of unless of course they are sick, some people give liquid vitamins but I don't, I think as long as there getting a balanced diet they don't need them.
They don't need any regular medication that I know of unless of course they are sick, some people give liquid vitamins but I don't, I think as long as there getting a balanced diet they don't need them.