I have 3 ferrets and a Chihuahua.
 
At first, Ginger, (my Chi) was a little aprehensive about Lucifer.  Then
we brought Kyba home 4 months later and the fun began.  They used to all
love to play together till Ginger gets tired of their antics and just
sits on them.
 
I guess it really depends on the temperment of the dog.  Ginger is an
overly friendly Chi.
 
Because of my other dog, I can no longer let them play together as he
is going blind and to me it is too dangerous for them to play together
anymore.  Ginger however seems to miss playing with them and trys to
engage them in play even if its through a gate now.
 
If this is a choice you plan on making, be very carefull.  Chihuahua's
can be very snippy dogs and some are just nasty by nature.  I guess I got
one of the exceptions to the rule.  Keep a safety area for both ferrets
and dog to escape to and watch carefully for signs of aggressive behavior
by both party's too.  They may be best friends or worst enemy's.
 
Sandy and the Zobel Zoo
Chuck(dog), Ginger Chihuahua
Lucifer, Kyba and Shea (da  Ferrets)
[Posted in FML issue 5130]