Leanne wrote:
>Both of these are good products.  Sukie I believe has mentioned before
>about the possibilities of the protein being too high as to later
>possibly form crystals.  I personally don't believe this would be
>true to an obligated carnivore and neither does my vet.
 
Depends on the ferret.  There actually are a number of ferrets who have
gotten cystine uroliths and the rate of these stones has increased in the
last year or so compared to earlier which is why they are under study.
Is it going to be the majority of ferrets?  No, that is not likely at
all.  Is it a serious problems when it occurs?  Yes.  In fact, sadly --
especially for male ferrets who are affected it is often fatal due to
urinary blockage.  We have two in our family with a history of cystine
uroliths, and this week I have heard from three people who encountered
them and I didn't know before had encountered them in ferrets.  In two
cases the ferrets have passed away.  I do not know if the uroliths were
the cause for one of those (the letter wasn't clear on that score) but
for the other they were the cause of death.  So, what we are discussing
with cystine uroliths is a problem which is unlikely to affect a large
portion of ferrets but which has a high chance of being fatal when it
does, especially for male ferrets.
 
It is NOT a "believe" or "not believe" situation of whether they occur
because they just plain do occur.  Acting as if they do not occur is
unfair to those here who have lost ferrets to them and those (including
Steve and I) who have almost lost a ferret to them.  I doubt you meant
to have your statement read that way, but that is one way it reads so I
think that you accidently hurt some people today besides us.  If you had
any concept of how hard it was to save Hilly you'd have worded it a bit
more carefully, I am sure.
 
As Nobel Laureate Dr. Richard Feynman wrote: "It doesn't matter how
beautiful your theory is, it doesn't matter how smart you are.  If it
doesn't agree with experiment, it's wrong." Since we know that cystine
uroliths occur and have increased in rate is becomes essential to find
out why that is specifically for ferrets, and having a chance to tackle
an emerging problem is an opportunity we in the ferret community rarely
get -- since research is so often "catch- up" work on common problems due
to poor funding of vet research specifically for the benefit of ferrets.
Right now I can think of only two studies which are clearly "emerging
medical problem" ones for ferrets: this and DIM.  ADV is somewhat one
because of the infection risk, but it has been known as a special risk
for some time now.
 
Furthermore, the typical mechanism in mammals for formation of cystine
uroliths is known.  Now we need to find out what the on-going study turns
up to see in what ways ferrets are similar or different from a number of
dog breeds, some lines of maned wolves, etc.
 
Mice are about 52% protein so it makes sense to assume that most ferrets
can deal with high protein levels.
 
If there is a medical reason to not use high protein percentages, though,
then those foods need to be avoided.
 
Cystine stones are one example, kidney disease is another, etc.  An
increase in the rate of cystine stones submitted to the urolith lab at
UC Davis over the last year plus has led to a study on cystine stones in
ferrets.  At this point the cause if unknown, though it is possible that
like with some types of dogs, maned wolves and some other animals there
may be some lines with a genetic kidney problem which makes it difficult
to deal with either cystine alone or with the COLA grouping of amino
acids, cystine, ornithine, lysine, and arginine.  (Cystine precipitates
out more easily than the other three in that grouping.)  Other possible
causes such a problem with specific foods is being looked at as well.
 
Here is some information for vets who treat ferrets to keep on file
about the new study:
 
Dr. Michelle Hawkins VMD DABVP (Avian) is coordinating this effort and
can be reached at:
 
2108 Tupper Hall, University of CA, Davis, CA 95616
1-530-752-1363 (phone)
[log in to unmask]
 
Also, among the folks who have encountered these, when the ferrets
survived (males especially may have fatal problems from the blocking)
almost all who have talked with me have found that their ferrets do
fine on a 35% protein level diet.
 
If a ferret does not there is info on medications in the FHL Archives at
http://fhl.sonic-weasel.org
and two vets who have successfully done this with ferrets -- so treating
vets may want a vet to vet consultation are Doctors Tom Kawasaki and
Mike Dutton (who has a publication out on the case he had, too).
 
If a male needs a PU here are both surgery guidelines and consultation
info: http://www.petcarevabeach.com/pen1.html
 
We had a PU planned for one of our two who got cystine stones (in his
case verified by urine pH since there was a malfunction causing his
sludge to be lost) because he blocked in his urethra to the point where
he almost was lost to bilateral hydronephrosis about a year ago, but
instead repeated cystos to empty his bladder manage to dislodge and
remove the problem as well as giving him time for the inflammation to go
down.  He has been gradually bouncing back and is now most of the way
there.
 
The only hint that I know about of what ferret might be susceptible to
forming cystine bladder stones is urine which is too acidic on a high
protein diet.  (The opposite of struvite stones which involve too much
veggie matter in the diet and urine which is too alkaline.)
 
I couldn't recall the right urine pH but
http://miamiferret.org/fhc/physiology.htm
says 6.5-7.5
 
Hilbert's has been much lower.
 
Again, though, most ferrets will not have a problem with higher animal
tissue protein levels (though plant protein levels too high tend to
indicate a food best avoided).
[Posted in FML issue 4903]