i noticed thismorning my 1 yr old has a missing toenail, as if it has just fallen off.

Will it grow back?

 

Also, about 6 months ago he had a parasite which we treated him for, but it involved an inflamed nostril which was abnormally larger than the other. We assume the infection has healed, however the nostril is still quite large. Is there anything we can do to resolve this or is it now permanent? I'm concerned it may be giving him grief or discomfort

A photo would be very helpful if possible. Is he in with other budgies that may have bitten his toe? If he recieved an injury to that toe a few weeks ago it may be that his nail just now finally became loose and fell off, it possibly won't grow back.

if the nail is totally gone it will not grow back, however if it's just broken off and is short it will.

 

The inflamed/large nostril we could not be sure about unless we knew what was causing it, e.g. scaley face or something else?

Welcome to the forum, and as everyone said a picture would help.

Totally agree with posting a picture/s on here so that we are able to try and help you with that - It could be a few things. If you are in doubt or can not post a picture May i suggest a AVAIN vet trip