Poor little thing.  This has got to be very hard to take for both of you.
Bone tumors (removed or not removed) *often* result in fractures, regardless
of their benign or malignant status, because they can soften the surrounding
bone by either stealing calcium salts or by not allowing calcium salts to be
normally deposited.  Everyone I knows recommends the removal of benign bone
tumors to save function, reduce possible discomfort, to insure the future of
the bone it is growing on, as well as because some feel there is a higher
risk of malignancy later.
 
Bone from almost every mammalian species takes between 4-8 weeks to reknit
once it is broken.  Ferret bone is so similar structurally to human that
doctors studying osteoporosis have suggested it be used as a model for human
bone.  In a fracture, a blood clot forms around the broken ends, which then
forms a callus--kind of rubbery and cartilage-like.  This callus will slow
ossify and reach the minimum strength it needs to support function in the
4-8 weeks mentioned.  It continues to get stronger--in some cases stronger
than the surrounding bone--and will gradually be remodeled until it
approaches an approximation of its former self.
 
This process can be derailed by infection, movement of the broken ends (they
heal but do not fuse), or even by poor nutrition (bones heal best with diets
rich in calcium, phosphorous, and Vitamins A, D, E, K and C).  I'm assuming
the ferret is being given an antibiotic to help prevent infection.  Not to
worry if the vet decided it wasn't warranted, just keep an eye out for signs
of infection, such as loose teeth, bad breath, gum discoloration or
swelling, and my personal favorite, puss.  This is something you should look
look for every single day until the danger period is past; a month or so.
Infection is bone's enemy.
 
Movement of the broken ends of a bone is usually controlled by splinting or
casting, but in a small animal like the ferret, jaws cannot be effectively
immobilized, and some say *not* to pin the mandible unless you have to
because of increased chance of infection.  The good news is it hurts to use
it, so the ferret will naturally use the unbroken side for eating.  Most
animals are "right-" or "left-jawed", just as many are right- or
left-handed.  Also, the skin of the lower jaw acts like a sling, holding
stuff in place.  If the bone is close together, it will heal.
 
As for the diet, because of the injury, duck soup is good, as is the
meat-based baby foods.  I would suggest adding a very small pinch of bone
meal to the portions to boost the calcium and phosphorus levels of the food.
This can be found in the vitamin section, but you can also get it at
petshops (packaged for turtles).  A tiny pinch per serving will be enough;
extra calcium and phosporus is eliminated in the urine, but some animals
*could* form kidney or bladder stones if too much is given to them.  I also
recommend when the ferret desires to eat a more normal diet, allow it to do
so, but carefully watch to make sure no injury occurs.  You might want to
soak the kibble in duck soup, broth, or even water to soften it.
 
Vitamins A, D, E, and K are fat-soluble, and are stored in fresh liver (you
can get some fat-soluble vitamins in commerical vitamin products like
Ferretone).  If you blend a small chunk in with the duck soup, it will only
make it better.  Beef or poultry liver are fine, but don't add more than
about 2 cm cube per serving; you don't want to overdose the ferret.  These
vitamins are part of the lipid-calcium-phosphous complex involved in bone
formation, and their importance in healthy bone formation has long been
known.  Vitamin C *increases* the absorption of calcuim and phosphorus (and
iron for you anemic types), as well as helping in the formation of bone.
Lack of citric acid results in bone becoming decalcified, and conditions
like scurvy take place, with loss of teeth and collapse of bone tissue.  I
know of no realistic toxic levels of Vitamin C for ferrets; the extra stuff
is eliminated in the urine, staining it orange.  A tiny pinch of powered
vitamin C per serving is all that is required.  BTW, Vitamin C helps
*prevent* the formation of bladder and kidney stones (eg, cranberry juice),
so giving a little at the same time as the bone meal is not only good
physiologically, but also prophalactically.
 
Now to the part you are really interested in.  I can't say what will happen
to *your* ferret, because I haven't seen it.  But I can tell you I have a
coyote skull where a 32 cal bullet passed through both mandibles, and
distroyed a 2 cm section on one side and a 4 cm section on the other.  Not
only did the coyote live (it was wild), but the mandibles healed completely.
Looked wierd, but quite functional.  That is typical.  In the vast majority
of cases, with proper care, diet, and rest, animals survive this type of
proceedure quite well, and the bone will knit together without problems.  To
illustrate the point, I've seen seal skulls, healed together after being
sliced by a propeller, longbones of deer, healed after being shattered by a
hunter's bullets, the skull of a fox that was obviously hit by a car, and
healed in a comma-like shape.  The strangest one is a collared peccary skull
with an embedded four-bladed hunting arrow in the area in the back of the
skull.  It projected 2 inches INTO the brain, yet the fracture was not only
healed, but remodeled, and the iron in the arrow tip was being disolved
away.  Must have been there 2 or 3 years.  You cannot pull it out; its there
to stay.
 
I've also seen skulls where the front part of the mandible was completely
gone, where one side or the other has missing (usually trapping or hunting
incidents).  Even if only one half of the jaw is attached, the other side
will remain functional.  I'll bet you eat most of your food on one side of
your mouth; the ferret will learn how to if it needs to as well.
 
What I'm saying is, IF your ferret is typical, in 5 weeks or so it might
have a crooked grin, but it will be fine.  Just watch closely for infection,
the greatest danger in *ANY* bone injury.  The ferret can get along fine
with clipped canines, and the part that is not attached might or might not
fill in over time.  But even if it doesn't, barring some secondary problem,
it shouldn't shorten the ferret's quality of life or lifespan if well cared
for.  At the very worst, you might have to make modifications to the diet,
such as softening it as described.
 
Bob C and 20 MO Domesticated Polecats with Ferretude.
[Posted in FML issue 2137]