>in the Fox book, he mentions studies that were done on ferrets that
>clearly showed diets containing grains could be harmful, and cause
>problems like renal failure, kidney and bladder stones.
The risk for stones connected to grains is specifically when the amount
of plant matter is very high, not for lower levels. Moderation in all
things.
It is not the nature of the grains themselves which is the problem, but
the proportion when there is simply too much. In that circumstance the
urine becomes too alkaline and then struvite uroliths (urinary stones)
form.
Yes, urinary stones -- of any type -- can cause blockages which can
lead to things like the kidney disorder, hydronephrosis, and to death.
It is a mistake, though, to think that any amount of grain will be to
blame. To get alkaline urine takes a good bit of plant matter.
Specifically from page 166 of James Fox's _Biology and Diseases of the
Ferret, second edition_: "any ferret eating a diet having ground yellow
corn as its primary ingredient can develop these urinary stones.
Magnesium ammonium phosphate (struvite) crystallizes when urine pH
rises above 6.4. As obligate carnivores with a normal urine pH about 6,
ferret metabolize crystine and methionine [two of the amino acids --
building blocks of proteins -- with proportions of amino acids
differing in different protein sources] in animal proteins and produce
an acid urine. However, metabolism of organic acids in plant protein
produces an alkaline urine that promotes struvite crystallization."
The explanation about the amino acids in brackets is my own note. If
you look up foods containing amino acid types you will find which foods
are higher or lower in certain amino acids. For example for methionine:
http://nutritiondata.self.com/foods-000084000000000000000.html
Humans have a relatively recent inclusion of animal protein sources
other than insects in the diet and there are recent bodies of work
which suggest that high methionine levels for us may shorten lifespan
in those who are susceptible and may play a part in the development
and continuance of Alzheimers plaques. Those are early studies still.
http://www.temple.edu/newsroom/2009_2010/12/stories/alzheimers.htm
http://www.ncbi.nlm.nih.gov/pubmed/20209467
http://www.physorg.com/news180169180.html
http://onlinelibrary.wiley.com/doi/10.1111/j.1474-9726.2005.00152.x/full
http://www.fasebj.org/cgi/content/abstract/8/15/1302
etc.
There is more work indicating that protein restriction appears to be
the component of caloric restriction which makes longevity differences
BUT that which amino acids are restricted for best results COULD differ
among types of animals depending on the other needs created by the
limitations of their own particular evolutionary line. I.E. since
rodents are more closely related taxonomically to humans work in them
is likely to be more applicable to us than to our ferrets. (BUT notice
in charts that the levels in things like beans, while higher than in
other plant foods are lower than in flesh foods and that vegetarians
NEED sources of certain essential amino acids such as beans and nuts;
if your protein levels go too low so will your T4 and T3 -- think
hypothyroid -- and those are involved in the basic energy production of
all of the body's cells.) Reduced methionine intake has been suggested
as a reason why humans vegetarians tend to fare better in both regards,
longer longevity and reduced dementia rates, but never expect it to
work the same way in Carnivora members like ferrets. Is there
methionine in plant based proteins? Yes, but the levels are lower than
in flesh based ones. Ferrets are adapted to deal with high levels of
methionine and their urinary system appears to need it.
Just like Vitamin D and Vitamin A intake concerns are different in
ferrets than in humans (with ferrets coping just fine with higher A
levels than we can deal with but developing hypercalcemia (with calcium
deposits in organs, especially in the kidneys or the heart and death
being possible) if they get too much Vitamin D, so too do ferret have
DIFFERENT AMINO ACID PROPORTION NEEDS than humans. BUT IT IS A MATTER
OF DEGREE. A bit of grain or potato to get the foods to stick together
is not going to substantially alter the amino acid ratio when the
primary sources of their amino acids are animal based (and those SHOULD
include animal sources other than flesh meats because organs, skin,
etc. do play a part in the right balance of the right amino acids as
well as minerals and more so FHL members should not think that food
grade animal meal and byproducts are automatically bad sources since
they give some essential nutrients. What matter for those two is their
grade. Not all are bad and not all are good.
Also, all people should take advertising with a grain of salt.
Performance Foods immediately investigated when people complained and
on its own recalled food years ago when an ingredient supplier screwed
up. Not all places as as reliable. You'll notice that one of the places
which advertises heavily on tv that it has a "natural", "grain- free",
"high-protein" food was one of the ones that had to recall due to
melamine content in 2007 and that it is now under pressure from the
veterinary group, VIN, due to what appear to be high levels of Vitamin
D causing kidney and other organ problems with calcifications forming
but that OTHER company has NOT begun a recall:
<http://www.truthaboutpetfood.com/articles/veterinarians-reporting-possible-blue-buffalo-dog-food-concerns.html>
>The company's focus has been on Blue Buffalo Wilderness Chicken
>Recipe, manufactured in April 2010 with a best-used-by date of July
>2011.
>
>Vitamin D toxicity, or hypervitaminosis D, induces bone loss and
>abnormally high serum calcium levels, which could result in kidney
>stones and the calcification of organs like the heart and kidneys
>if left untreated.
http://www.accessdata.fda.gov/scripts/newpetfoodrecalls/
can get you to the page on them in 2007 using the Chinese protein
additive which instead turned out to be melamine by just putting
Blue Buffalo
in the search box, clicking the search "button" on the website and then
opening the results.
Personally, I respect places that do NOT have to be forced into recalls
but instead have a history of investigating, correcting, and recalling
BUT have few such problems. Also, I respect places which sell what they
say that they sell. Our ferrets thrive with TF in their diets. It's
not the only thing we feed, and right now we are teaching a new kit,
Orville, about also eating cooked homemade meat, skin, and organs. We
like to give a range of foods but are careful about which foods we use.
We do use TF.
A little bit of grain is not going to alter the amino acid proportions
enough to endanger the kidneys.
BTW, there are multiple types of kidney stones/bladder stones/urinary
tract stones/uroliths so when a ferret gets them DO check BOTH the
stone type by sending it to an appropriate laboratory -- with many of
these being university ones for uroliths -- and DO check the urinary
pH. (We have a ferret who gets cystine uroliths so needs protein
restriction which has gotten her over 6 additional years so far since
she will turn 7 next month and recently lost another who got an
additional 7 years of life due to protein restriction (passing just shy
of 8 years of life) to also manage a tendency toward cystine uroliths
in both of them. ALWAYS get the urine pH, the urine concentration
numbers, and if a stone or sludge is present always have the type
discovered when a ferret has a renal problem. Not all vets think of
those so remember them. Kidney disease is a real heart- breaker so
care has to be taken to not over-react later for others. ***There is
an easy way to set one's mind to rest: use urine pH testing strips.***
The needed approaches differ with different types of uroliths so some
need more animal protein to avoid struvite uroliths, while others need
to have a group of 4 amino acids reduced to avoid cystine uroliths --
a genetic condition which people are finding is less rare in domestic
ferrets than thought ever since the high protein foods have appeared
though still a bit rare, and yet others may need different approaches
to avoid stones high in calcium, or other stones.) Again, for most
ferrets a bit of grain to hold together the rest of the food is not
going to significantly alter the ferret's urine pH so the renal risk
from that isn't there. (Is it possible that some rare ferrets might
be extra susceptible genetically? Hey, genetic variations happen all
the time so I won't discount rare exceptions being possible but so far
as far as I recall I have NEVER heard of a ferret who could not deal
safely with low levels of grain in relation to urine pH and the
associated urolith and renal worries, so I think that concern is
misplaced in this situation. Again, try those urine pH testing strips
(human ones are fine) for relief.
[Posted in FML 6839]
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