One of my pet budgerigars is unwell. It fluffs up its feathers
permanently and it does not feel very warm to the touch. It seems in
discomfort and is unsteady on its feet particularly when it moves its
head. It spends some of its time with its eyelids closed, and sometimes
tries to sleep in the day with its head folded back. It sometimes opens
its beak noiselessly apparently gasping for breath although its tail
doesn't twitch much. It can find the strength to fly short distances
when required, preens itself and keeps itself clean but only eats a
little. Some symptoms seem to come and go in waves. I reckon it is
some kind of cold(/flu) however this has been going on for several days
now.
The other budgie in the same cage is perfectly okay.
Has anyone any advice?