Radiographs and palpation are both fairly poor when it comes to pinpointing
blockages - plain radiographs pick up about 10% of blockages, and barium
studies may double that.  Palpation only reveals them when they are causing
a lot of pain.
 
Most of the successful surgeries come about as a result of a high index
of suspicion, and vague GI signs, such as inappetence, diminished stools,
perhaps vomiting.  Cutting on a ferret for a foreign body is often a "gut"
feeling (no pun intended) by the vet.
 
This said, if he continues to show GI signs, and that filter doesn't show
up, I would suggest you contact your vet on Monday and let him know your
concerns, so that appropriate action can be taken, whether it be continued
observation or surgery.
 
Regarding the ingestion of tobacco - the nicotine in tobacco usually causes
vomition, salivation, dilated pupils, staggers, involuntarily urination,
and seizures, if the level is high enough.  If you haven't seen this, it
is likely that either an insignificant or no tobacco was ingested.
 
With kindest regards,
Bruce H. Williams, DVM, DACVP
 
Join the Ferret Health List at http://groups.yahoo.com/group/Ferret-
Health-list
 
[Note: one of the FHL's members also told of a ferret who died from
poisoning after eating a cigarette filter and gave a fine warning.]
[Posted in FML issue 3356]