We have the same problem, also.  We have two geriatrics that have to be
syringe fed.  Here are a couple of tricks that have worked for us.
 
1. Wash the syringe and plunger thorougly and put them back together while
   still wet.
 
2. Before using syringe and plunger wet both and pump a little water
   through them.
 
3.  Dip the plunger into the food and then put it in the syringe.
 
This last one actually works best.  However, even using these tricks the
things don't last forever.  They are cheap to buy.  Check out a Foster &
Smith catalog.  That's where we order ours from.  Hope this helps.
 
Cheryl
--
The Critterpen by Chemayn
Cheryl M. Nordgulen
Olympia, WA  98506
http://home.earthlink.net/~critterpen/index.html
Walk in peace, speak softly, love much.
[Posted in FML issue 2458]