Several suggestions---- 

Feed with a syringe - I believe you're already doing that, but am not
positive - you could probably put some sort of small tube on the end
of the syringe if you are having trouble fitting a syringe into his
mouth - look at some wildlife rehab supplies sites for other ideas
along these lines

Have a feeding tube surgically implanted - probably the best, most
realistic option

Insert a feeding tube for each feeding - I feed orphaned opossums with
a properly sized French tube and catheter; it's easy to learn

Find a nearby vet school who may be willing to take him on as a
learning opportunity

Find a nearby orthopedic vet who may be willing to work with you

Good luck. If you are unable to find a way to get enough nutrition into
him, your options may become very limited. I also have to go home every
day at lunch to feed ferrets, so certainly understand your dilemma.

Katharine

[Posted in FML 6094]