Catherine asked about putting the big guys together with the little guys.
We raised our Old English Mastiff, Der Beschutzer (the protector) with our
first ferrets.  Schutzie topped off at 225 lbs, so luckily he was extremely
sweet and gentle in the house, even though he was still extremely protective
(that is, on his guard, NOT mean or dangerous) whenever strangers came
around.  At night Schutzie shared the same room with our ferrets, and we
never had any problems.  But we did provide a raised platform for Schutz to
climb onto to sleep, so that he could have some peace from the playful
antics of the little critters.  One thing I would caution about big dogs is
that even though they are friendly toward your smaller pets, they can
accidently injure them with their play or clumsiness - a carelessly placed
huge paw, or just rolling over on them could be disastrous to a tiny ferret.
But at least Mastiffs are not overly roudy dogs.  Overall, Old English
Mastiffs, if well-bred, are not vicious (and they were never bred to hunt
vermin or small game, so they don't have that instinct).  Instead, they are
gentle protectors; I would be much more concerned about some of the terrier
breeds - of which I am SURE there are many wonderful exceptions!  One thing
I would suggest if considering the English Mastiff is to make sure you buy
from a reputable breeder who has in fact bred for sweetness and also that
there is proof of longevity in his pedigree - cancers seem to be a problem
in some lines, and our poor Schutzie only lived to be 5 years old.
 
Joanie Williams at Ferret Haven
[Posted in FML issue 1733]