Are Cereals Bad for Dogs?
There seems to be a lot of chatter on the web
about the suitability of grains and cereals in a
dog’s diet. Looking at what is out there, it seems
that a lot of the opposition to these ingredients
is put out by those advocating raw food or
home-cooked diets, which might be a little biased,
so I’ve tried to find what seems to be the middle
ground - an objective assessment of the question
‘Are grains and cereals bad for dogs?’
Before we start, a couple of points to ponder:
1) There is a theory, which seems
reasonable to me, that dogs have evolved over many
generations of breeding and human interaction to
eat a diet that is basically human (before dog
foods, they ate what we ate for thousands of
years) . They are a long way from the wolf of
their ancestor, who incidentally tends to have a
much shorter lifespan, so it may not be too
helpful to compare the diets of the two.
2) All dried kibble, be it normal or
‘grain free’ has starch in it - you can’t make a
kibble any other way. So if you are feeding an
expensive ‘natural’ grain free dried food thinking
it is free of dietary starch, think again!
3) Many thousands oftop quality dogs (including
Kennel Club champions) are fed on a cereal based
diet and (apart from the controversary over
genetic deformities due to inbreeding!) have
excellent coats and body condition.
Dogs have the ability to consume large quantities
of protein and then convert that protein into
energy in addition to muscle. They also have the
ability to convert many carbohydrate sources into
the same kind of energy. This ability to utilize
both carbohydrates and proteins as an energy
source explains how we are able to feed our dogs a
high carbohydrate diet, particularly when we feed
processed carbohydrates that are easily digested
by dogs. So, essentially we are meeting the dog's
protein requirement with meat, and then meeting
their energy and fiber requirements with
carbohydrates instead of the protein they would
often use in the wild.
Using carbohydrates as an energy source has
benefits for the manufacturer and consumer.
Carbohydrates are less expensive and more readily
available as an energy source than proteins.
Carbohydrates are also essential in the formation
of dry pet food. The starchy carbohydrates are
used to add structure, texture, and form to
kibbled food helping to create a product that is
stable and easy to feed. Canned foods could be
composed without the addition of carbohydrates,
but dry kibble could not exist in its current form
without carbohydrates.
Carbohydrates used in dog foods generally include
the starchy portion of a plant that can be easily
broken down in the digestive tract of the dog.
Soluble carbohydrates are found in high
concentrations in cereal grains such as rice,
wheat, corn, barley, and oats. The cooked or
extruded forms of carbohydrates found in most pet
foods are easily and rapidly digested. It should
be noted that not all forms of starch are easily
digested by dogs and cats. Raw cereal grains are
digested much more slowly in the intestine and
there are some starchy carbohydrates, including
raw potatoes and bananas that are completely
resistant to digestion in pets.
More on this at (http://www.peteducation.com/article.cfm?c=2+1659+1661&aid=655)
I also include this excellent scientific
examination of the question from Susan G. Wynn
which seems freely available on the web. It
answers more specific questions on a dog’s
physiology, and seems remarkably balanced in its
conclusions.
So are grains bad for dogs?
There is no nutritional requirement for
carbohydrates for dogs. There is also none for
fiber, though we well recognize the benefits, and
the same could be said for other nutrients like
glutamine, Vitamin C and even probiotics.
Carbohydrates contain calories. Grains contain
carbohydrates, vitamins, minerals, fatty acids,
fiber, and a little protein.
Recently, carbohydrates included in diets for dogs
have been vilified, especially in the form of
grains such as rice, wheat, corn, barley, oats,
etc. The reasons are myriad:
Fallacy 1:
Dogs have a shorter GI tract than people, so they
cannot digest grains unless they are partially
digested first.
Fact:
Decades of research proves that dogs digest grains
as well as carbs quite well.
• The lack of salivary amylase has been stated to
be one reason why dogs don’t digest carbohydrates
well. Why would dogs need salivary amylase when
they gulp their food? Dogs produce potent
pancreatic amylase as well as ‘brush border’
enzymes to digest their carbs (like humans).
• Most digestion of carbohydrate occurs in the
first part of the small intestine (like humans).
• Some have stated that dogs have more acidic
stomachs and retain food in their stomachs longer
than people, making a meat based diet more
suitable for dogs since protein is initially
digested in the stomach. The pH of the dog's
stomach ranges from 1.08 to 5.5 (Ouyang et al.,
2006, Smith, 1965, Buddington et al., 2003, Sagawa
2009). For people, the pH ranges from 1-4
(Krause's Food and Nutrition Therapy). This makes
the acidity equivalent between the species, with
the dog ranging slightly more alkaline in certain
settings.
It is true that like humans, dogs cannot digest
cellulose, a single structural carbohydrate used
by plants to form stalks, seed coats, vegetable
structure etc. Only herbivores like cows can
digest cellulose, turning it into some other vital
nutrient, but it doesn’t seem reasonable to
compare the GI tracts of dogs and people to cows.
Canine digestive physiology resembles human
digestive physiology much more closely, so grains
and veggies should be cooked or ground as finely
as possible (either before or during the act of
chewing) to derive the benefits contained in
them.
Fallacy 2: Feeding carbohydrates place
stress on the pancreas.
Fact:
The pancreas was created to produce enzymes to
digest fats, proteins and starches. That’s its
job. Many people feed digestive enzymes as a daily
supplement, I suppose to support what they see as
this delicate flower of an organ do its job with
protein and fat. There is evidence that
supplementing enzymes actually downregulates the
pancreas’ own production of proteases. That’s not
necessarily a good thing - see my blog from
1-27-09 for more information. But during bouts of
pancreatic inflammation (otherwise known as
pancreatitis), where those very enzymes are
released to cause inflammation and damage to the
pancreas and surrounding organs and tissues, the
treatment is to reduce fat in the diet in order to
suppress production of those enzymes. The
treatment is…….high carbohydrate diets - and they
work.
Fallacy 3: Since food moves through the GI
tract rapidly, there is no time to ferment
carbohydrates and therefore no need for them.
Because carbohydrates are not fermented, if they
are included in the diet they will cause gas and
voluminous stools.
Fact: Like humans, dogs harbour many lactic
acid producing bacteria which ferment fibers
contained in grains. This fermentation itself can
cause gas. Odiferous gas can also be caused by
clostridial organisms. Clostridia are more
numerous in the GI tract when dogs are fed a high
meat, high fat diet such as raw, grainless
diets.
Fallacy 4: Grains cause allergies.
Fact: If dogs have the genetic
predisposition to develop food allergies, they can
become allergic to certain foods. A recent review
of 7 studies indicates that dogs are most commonly
allergic to the following foods (in descending
order): beef, dairy, wheat, egg, chicken,
lamb/mutton, soy, pork, rabbit and fish. In cats,
the most common allergens are beef, dairy, fish,
lamb, poultry and barley/wheat (in equal numbers),
egg and rabbit in equal numbers. I will admit that
I’ve seen higher numbers of corn allergy than
would be suggested by these numbers, as well, but
please note that grains do not constitute the
majority of allergy offenders.
While dogs do not require the carbs found in
grains or potatoes or any other food, there are
some instances where you still might derive
benefit from them being there. For instance,
grains contain certain fibers that are beneficial
for the growth of probiotic bacteria in the gut.
They also contain various required vitamins and
minerals. And since grains, as compared to meats,
contain lower fat contents, they can be used as a
“place-holder” in a diet that fills a dog up while
reducing the fat content. I’ve seen people feed
pitifully small amounts of raw diets to dogs whose
weights needed better control. Poor hungry dogs!
This is not to say I approve of diets formulated
with high concentrations of carbohydrates simply
to limit cost. I just want to note that there is
no reason to expressly avoid them unless your dog
has a specific intolerance to them or some
condition that requires use of a diet that is low
in carbohydrates. And remember that healthy cats
are another matter entirely- they are true, pure
carnivores, and as such, should probably not be
fed diets that contain noticeable carbohydrate
levels.
Back to carbohydrates vs grains - take this to the
bank: If it’s a dry kibble, it contains
carbohydrates. This is because kibble is made by
the process of extrusion, which doesn’t work
without a certain minimal level of starch. So
those grainless diets that sound so good, and so
paleolithic - yeah, those contain carbohydrates.
Just in the form of potato, tapioca, or other
starch containing food.
My point is that if we are going to eschew grains,
let’s do it for the right reasons, and if we
instead want to avoid carbs, we *have* to read the
labels carefully.
Susan G. Wynn, DVM,Registered Herbalist(AHG)
Georgia Veterinary Specialists, Sandy Springs, GA
Clinical Resident in Small Animal Nutrition,
University of Tennessee
www.susanwynn.com, www.vetnutrition.blogspot.com
Conclusion?
Although carbohydrates are not an essential
component of the dog diet, they do provide an
excellent and readily available energy source
which, if cooked and prepared properly, the dog
can digest easily. They have an advantage for
consumers in that the product that we buy is able
to be formulated to be stable as well as
nutritionally balanced.
Dogs are just as (if not more) likely to develop
an intolerance or allergy to meat as they are to
cereals.
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