>I was wondering if anyone could tell me why pine shavings are harmful to
>ferrets, but not considered harmful for hamsters or rabbits (if indeed they
>aren't harmful to them.)
 
Pine shavings ARE harmful to all small animals (and humans too).  They can
cause respiratory disease, liver changes and skin problems.  There are
studies going back to 1967 reflecting these problems.  The following is an
article published by the House Rabbit Society.
 
Sandi Ackerman
Best Little Rabbit, Rodent & Ferret House
Seattle, WA.
 
 =================================================
The Dangers of softwood Shavings
by George Flentke, Univ. of Wisc
The use of pine and cedar as litter for small animals & rabbits should be
avoided.  Other superior litters, such as recycled paper and aspen shavings
are available and you should steer potential adopters and those who already
have rabbits to these safer alternatives.  There are two major concerns with
the use of cedar and pine shavings as litter.  The first is the documentend
alterations in the liver's specialized tools, called enzymes, that can alter
your rabbit's ability to handle standard drugs that your vet will use in the
treatment of your pet.  The second is the relatively poorly characterized
cancer risk.
 
When you open a container of pine or cedar shavings you will instantly smell
the "aromatic" nature of the litter.  That smell is where the problem lies.
The odor is from the natural volatile chemicals in the wood called phenols.
Thus one of your best detection methods for determining an unknown bag of
shavings is your own nose!  This odor, and the phenols that cause it, are
not found to the same amount in hardwood shavings, thus hardwood shavings,
aspen being one of the most common, are considered a much safer litter
material and can be recommended for all small animals.  The phenols in the
softwood (pine and cedar) shavings cause changes in the liver's enzymes.
Your rabbit's liver tries to remove the phenols by producing more of certain
enzymes that destroy these chemicals; this is a natural part of you and your
small animal=92s defense against environmental toxins.  Our bodies always
produces a low constant level of these protective agents; the problem occurs
when constant exposure to pine phenols causes the small animal to produce
substantially larger quantities.
 
The most characterized and potentially the most troublesome problem is that
these enzymes are also used to remove drugs.  Remember that removing drugs
is just as important as their administration; we want the drugs to have the
desired effects and then go away when we no longer need them, so knowing
exactly how long they will be around is an important part of every drug's
action.  If these enzymes are elevated, then the time a drug will be in the
body and have the desired effect is much less than predicted.  Some of the
drugs affected are xylazine and ketamine, the most popular injectable
anesthesia's.  Other important drugs include dexamethasone, theophylline and
all of the opioid painkillers, such as butorphanol, that are commonly used
for rabbits.  In rodents, for example, constant exposure to
phenol-containing litters reduced drug effectiveness by greater that 40%.
This is the main objection to softwood litters.  We as caretakers are always
limited in what safe drugs we can use on small animals, and decreasing their
safety further by making them unpredictable should be avoided if at all
possible.  The second objection to softwood shavings exposure as a cancer
risk is less concrete.  Epidemiological studies in humans point to increase
risks in people who work in saw mills, but the issue of volatile phenol
involvement is not clear.  Cedar shavings have caused increased risk for
cancer in certain rodents, but in many ways this work was skewed by the
nature of the experiment.  Thus the evidence is, at best, only suggestive.
Combined with the other health difficulties though, we should seriously
question the use of pine and cedar in any litter for the pet industry.  As a
side issue, for those on the west coast, Ponderosa pine needles have been
mentioned as alternative litter; this should be avoided at all costs.  The
material has caused spontaneous abortions in cattle and other domestic
species and caused other hormonal disturbances.
 
   ====================THE END========================
Guinea-Pigs list
  http://www.aracnet.com/~seagull/Guineas/guinea-pigs.shtml
House Rabbit Society - Seattle, WA
  http://www.houserabbit.org
[Posted in FML issue 1973]