CAT & DOG NUTRITION: THE THIAMINE ISSUE
By Dr.Michael W. Fox
Thamine
(vitamin B1) deficiency in pet foods is an issue of
clinical importance and in spite of proclaimed advances in the science of pet
food nutrition and ingredient formulation, there have been five major pet food
recalls since 2009 in the United States because of thiamine deficiency, several
cats developing clinical signs of deficiency disease. Two recent articles published
in the Journal of the American Veterinary Medical
Association ( 1&2) highlight this issue which cannot be simply fixed by
manufacturers adding more thiamine supplement to their products.
On
March 10th 2013, Diamond Pet Foods posted that
it is voluntarily recalling limited production codes of Premium Edge Finicky
Adult Cat Formula dry cat food, Premium Edge Senior Cat Hairball Management
Formula dry cat food, Premium Edge Kitten Formula dry cat food, Diamond
Naturals Kitten Formula dry cat food and 4health All Life Stages Cat Formula
dry cat food. Tests conducted by the company indicated the products might
have a low level of thiamine. There have been other cat food recalls for canned
as well as dry foods by other vigilant companies because of thiamine
deficiency, but none to my knowledge with commercial raw meat-based cat foods. Thiamine is essential for
cats in maintaining normal nervous system function.
Symptoms of thiamine
deficiency displayed by an affected cat can be gastrointestinal or neurological
in nature. Early signs of thiamine deficiency may include decreased
appetite, salivation, vomiting and weight loss. In advanced cases, neurological
signs can develop, which may include ventriflexion (bending towards the floor)
of the neck, wobbly walking, falling, circling and seizures.
Veterinarian
Elizabeth Katz (3) notes that “thiamine is a
water soluble B vitamin important for helping the body to utilize carbohydrates
as energy through a process called the TCA cycle. Thiamine is a necessary
cofactor involved in this energy producing process…..Thiamine is naturally
found in various food sources some of which include whole grains and
vegetables, legumes, and brewer's yeast. But, it is also present in muscle
tissue of animals, particularly in the liver and heart. The mere presence of
thiamine in a food may not correlate with its activity or bioavailability.
Several factors may affect the bioavailability and/or activity of thiamine in
processed foods. As much as 50% to 100% of the thiamine present in raw meat can
be inactivated by one or more of the following processing methods: heat, high
amounts of sulfur based food preservatives, i.e. sulfur dioxide, and certain
thickening additives in canned foods which may alter the pH of the food…. Raw meat diets
are not exposed to heat as canned and dry diets are, therefore the thiamine in
these diets remains intact. These diets also do not use any of the additives or
preservatives used in canned foods.”
Many
seafood products contain thiaminase which destroys
thiamine, cod and salmon being two exceptions. A high corn/grain diet calls for
more thiamine. Thiamine is often prescribed for human patients with diabetes
Type 2 and progressive kidney disease, these being common health issues in the
cat population today being fed (as well as their mothers) on
thiamine-compromising diets which may play a role in the genesis of feline
diabetes and chronic renal failure. The major pet food companies continue to
include corn and grain ingredients---primarily human food and beverage industry
byproducts such as corn meal, corn gluten meal and brewer’s grains which are
also included in the diets of factory farmed animals. A review article on the
dietary hazards of corn and grain byproducts to farmed animals (4) raises
several red flags for farmed animal health and by association, the health of
cats and dogs whose diets include such co-products from the ethanol, high
fructose and brewing industries. Notably, the high sulfur levels in corn byproduct
can cause brain disease with polioencephalomalacia developing in calves fed
high levels of corn gluten. Sulfur converts into sulfide which can alter the
bacterial content in the ruminant’s digestive system increasing the numbers of
those that produce thiaminase and destroy thiamine. Both corn gluten meal and
brewer’s grains are high in sulfur and also phosphate, which these authors
stress is a significant animal waste environmental management problem and a
serious (aquatic) contamination concern. Do high phosphate levels contribute to
kidney disease in cats and other species that benefit from prescribed phosphate
binders?
An article published in Australia (5) reported: “Some pet food
suppliers treat products
with high levels of sulfur dioxide to preserve the meat and to disguise signs
of putrification (sic). But vets are calling for tough rules to limit the
amount of chemicals used because it is proven to cause thiamine deficiency and
lead to neurological problems. Dr Anne Fawcett, companion animal veterinarian
at the University of Sydney’s Faculty of Vet Science, treated a thiamine
deficient cat fed exclusively on supermarket bought kangaroo meat packaged for
pets. The food was tested and found to have concentrations of sulphur dioxide
almost double that allowed for human consumption. Sulphur dioxide is a known
cause of thiamine deficiency in humans and animals. “In this day and age, with
the knowledge that pet food manufacturers have, this is an entirely preventable
condition,” Dr Fawcett said.
Susan
Thixton (www.truthaboutpetfood.com)
wrote to the FDA about this concern and posted their reply which included the
following pertinent information:
Dear
Ms. Thixton:
We
are responding to your e-mail of May 1, 2014 in which you
ask several questions about sulphite (or sulfite) preservatives and their use
in pet food products. In our response we will copy each of your questions and
then provide the answer to the question.
You
asked: “What are the names of various sulphite
preservatives?”
The
sulfite preservatives permitted in food for animals,
including pet foods, are potassium bisulfite, potassium metabisulfite, sodium
bisulfite, sodium metabisulfite, sodium sulfite, and sulfur dioxide. The table
below lists the regulations for these substances pertinent to animal food that
appear in Title 21 of the Code of Federal Regulations (21 CFR).
You
asked: “[…] what would consumers look for on the label
if they wanted to avoid pet foods using sulphite preservatives?” and “Would any
of these preservatives be used and not listed on the label?”
When
any of these preservatives are used in any animal food,
a statement such as “preserved with sulfur dioxide” or “sodium sulfite (a
preservative)” has to be in the list of ingredients on the label of the
product. Therefore, if one of the sulfite preservatives is added by the
manufacturer of an animal food product, the consumer should be alerted to the
presence of the preservative when they look at the listing of the ingredients.
There
are a few allowed exemptions from the requirement to
declare an ingredient in the ingredients list on a product label when the
product is made from two or more ingredients. These exemptions are very narrow
and the pertinent regulation is Part 501.100(a)(3) in 21 CFR. These substances
are the incidental additives. To be an incidental additive, the amount of the
additive in the product must be at insignificant levels and the additive cannot
have any technical or functional effect in the food. Thus, the only way a
manufacturer would not have to declare a sulfite preservative in the
ingredients list of a product would be if the sulfite preservative was present
in the product by reason of having been incorporated into the product as part of
another ingredient, in which the sulfite did have a preservative effect, but in
the final or finished product the sulfite no longer has a preservative or other
technical effect.
As
indicated in the various regulations, sulfite
preservatives should not be used in meats or food recognized as being a source
of vitamin B1 (thiamine or thiamin). The reason is that sulfite preservatives
are known to destroy vitamin B1 and vitamin B1 is an essential nutrient that
participates in many biochemical pathways in the human and animal body. It is a
water soluble vitamin, of which the body does not store significant reserves;
therefore, regular dietary intake is very important. Because sulfite
preservatives destroy thiamine, sulfite preservatives should not be used in pet
foods that are marketed as being complete and balanced or that have thiamine
(thiamine hydrochloride, thiamine mononitrate) in their list of ingredients.
We
hope this response provides answers to your questions.”
It is surely
clear that the rotting, disease- condemned and contaminated meats that go in to
many pet foods are treated with these preservatives that put animals at risk.
Additional concerns that I have about the inclusion of corn in pet foods are
based on the evidence that I have compiled about the health risks of
genetically engineered/modified (GMO) corn and also GMO soy (see special report
posted on www.drfoxvet.net), significant
quantities of which continue to be included in many cat and dog foods and which
(along with peas and pea fiber now also being put in to pet foods) are high in
phytoestrogens. Such ingredients, which have no place in a carnivore-cat diet,
also contain high levels of phytases.
These bind and prevent the absorption of essential minerals, a concern
compounded by evidence that such essential minerals, that play many vital roles
in enzyme and neurologic function as well as skeletal and muscle and organ
maintenance, are actually deficient in GMO crops.
The
diet related health problems in cats and dogs today, as
documented by myself and two other veterinarians ( Marion E. Smart a professor
of animal nutrition and Elizabeth Hodgkins, former director of technical
affairs with Hill’s Pet Nutrition) in NOT
FIT FOR A DOG: THE TRUTH ABOUT MANUFACTURED CAT & DOG FOODS (6) cast a
shadow across the veterinary profession that has been deeply influenced by the
multinational pet food companies which are a subsidiary of the now global
industrial agribusiness industry. This shadow affects all of us who depend upon
this food-chain for our own sustenance, much of it being unethically subsidized
by our government from our tax dollars which indirectly feed the coffers of an
increasingly dysfunctional health care system, as I describe in my recent book HEALING
ANIMALS & THE VISION OF ONE
HEALTH (7). Our dogs and cats have become the modern-day canaries in the
mine-shaft alerting us, in the health problems they manifest, to hazards in our
shared environment which includes the food system in which they and most of us
still participate outside of the expanding umbrella of organically certified
whole foods. We should all get under that umbrella, and there are several pet
food manufacturers now getting under it, which as a veterinarian I applaud.
REFERENCES
CITED
1. Jessica.E.Markovich
et al (2013) Thiamine deficiency in dogs and cats, JAVMA Vol. 243: 649—666
2.Jessica
E. Markovich et al (2014) JAVMA Analysis of thiamine
concentrations in commercial canned foods formulated for cats, Vol.244: 175-179
3.Elizabeth
Katz (2014) Thiamine
in a Raw Meat Diet posted on www.feline-nutrition.org
4. K.D.Raush and
R.L.Belyea, (2006) The Future of Coproducts from Corn Processing Applied Biochemistry & Biotechnology, 128:
47-86
5. Editorial
(2014) PETS are being poisoned
by dangerous levels of preservatives in commercial
pet food that can leave dogs and cats with brain damage, veterinarians have
warned, posted on May 11th/14 at www.news.com.au
6.
M.W.Fox et al ( 2009) Not Fit for a Dog: The Truth
About Manufactured cat & Dog Foods.
Fresno CA Quill Driver Books
7.
M.W.Fox ( 2011) Healing Animals & The Vision
of One Health.
CreatSpace/Amazon.com
