Ailing Canary

Question
Hi, I work at a pet store where we have a very sick canary. We have a limited amount of avian specialist we can go to for vet visits and most more than an hour drive away which is difficult to do due to limited hours). The bird is having weight loss despite eating, diarrhea, puffed feathers, feather loss/degeneration, heavy breathing, but is still moving around alright, keeping its beak trimmed, eating and drinking.

When we brought it to the vet the first time he got a stool sample taken and was given Bene-bac to be given orally and to give warm water soaks to the birds very raw cloaca twice a day. The bird was also treated for lice(which is partly why the bird was brought to the vet along with the diarrhea)

My main question is how can we put weight on this bird so that it has the chance to get to the vet again before wasting away. And what might you think is going on with the bird?  

Answer
Well, I am not a vet but my guess is she has some sort of bacterial, or some other infection.

As for being underweight it will be very hard to get a bird with diarrhea to gain wieght.

I would try giving him some extra sunflower seeds ( not usually great for birds, because they a very fattening) as this might help keep his weight up until you get him to the vet.

He needs vet care as soon as possible.