Because
you have a choice! An Insider's Guide
to Choosing the Right Food for Your Pet
Basic Nutrition - What needs to be in my pet's food?
It has been said that you are what you eat – and the same
that is true for us also goes for our pets. Good nutrition is a
key element to ensuring a happy, healthy pet.
Pets are no different to ourselves, in needing a regular supply
of food in order to maintain the the very complex processes that
go on in body cells, enabling growth and suplying energy.
There is one basic difference between cats and dogs that needs
to be understood. The cat is considered by scientists to be a strict
carnivore and the dog an omnivore (can digest and utilize plant
and animal food sources).
It is almost impossible to ensure good health with a cat and feed
a non-meat diet - they were never intended to be vegetarians!
Dogs,
however are much more flexible in their aproach to eating and do
not have to consume just meat. However, just because by definition
they are omnivores does not mean that a vegetarian diet alone is
the most appropriate way to feed.
The National Academy of Sciences in the US have produced two useful
guides for nutrition of dogs and cats, which explain in easy to
understand terms the importance of the various components of a healthy
diet - download a copy of these here.
There's also a complete and very comprehensive list of the recommended
levels of nutrients for dogs and cats
produced by AAFCO (Association of American Feed Control Officials).
Pets have several requirements that have to be met by the diet
that we provide:
Protein
Proteins are made up of amino acids which are the basic
building blocks of life, being essential components of living
cells. Proteins are a major part of an animal's diet because
the body cannot synthesise some of the amino acids in sufficient
quantities (Dietary protein contains 10 specific amino acids
that dogs cannot make on their own.)
An increased intake of protein is required during periods
of growth, pregnancy and lactation. However, too much protein
in the diet can lead to its conversion by the body into fat,
which is undesirable, so consideration needs to be given to
the protein content of food at specific life stages of a pet's
growth.
Cats require a higher protein level than dogs. This may be
due to the cat's inability to regulate the rate at which liver
enzymes break down protein. If dietary protein is in low quantities
or not available, the cat's body will soon start breaking
down the protein in its own muscle.Cats require a high amount
of the amino acid taurine for their body functions and therefore
this nneds to be a consideration if not feeding a commercial
brand with added taurine.
Fats
Dietary fats, mainly derived from animal fats and the seed
oils of various plants, provide the most concentrated source
of energy in the diet, as well as giving an acceptable texture
and 'mouthfeel' to the food. They supply essential fatty acids
that cannot be synthesized in the body and serve as carriers
for important fat-soluble vitamins. Fatty acids are involved
in many aspects of health, from the cellular level upwards.
Arachidonic acid is one of the essential fatty acids. Dogs
can manufacture this from linoleic acid or gamma-linolenic
acid. Cats can not. Arachidonic acid is found in animal fats
which must therefore be included as part of the diet. Like
dogs, cats also require linoleic acid, another fatty acid.
Carbohydrates
Omnivorous animals get some of their energy from carbohydrates.
This food group includes both simple sugars (such as glucose)
as well as complex sugars (e.g. starch) which consist of chains
of simple sugars.The major sources of carbohydrates in commercial
dog foods are cereals, legumes, and other plant foodstuffs.
Carbohydrates may be converted by the body into fat.
Water
An animal cannot survive for longer than a few days, or
even hours without water. There is a continual loss of water
through skin, urine, faeces and breathing, and this must be
replaced either as fluid or through the breakdown of food
ingested, which is why it is most important that an adequat
esupply of fresh water is always abvailable to your pet.
Vitamins
and minerals
Vitamins and minerals help to regulate the body processes.
Most cannot be synthesised and therefore must be provided
in the diet. Interestingly, unlike humans there is no dietary
requirement for vitamin C in most pets, as they can synthesise
it from glucose.
Cats lack the enzyme which can convert beta-carotene to retinol,
the active form of Vitamin A. Therefore, they require a preformed
Vitamin A, which is present only in foods of animal origin.
Many animals can synthesize niacin, a B vitamin, from the
amino acid tryptophan. Cats can not manufacture it in sufficient
quantities, thus require higher amounts in their diet.
A number of minerals have been discovered to play a part
in the regulation of body processes, the requirements for
some being greater than others. Calcium and phosphorus are
crucial to strong bones and teeth. Dogs need magnesium, potassium,
and sodium for nerve impulse transmission, muscle contraction,
and cell signaling. Many minerals that are present only in
minute amounts in the body, including selenium, copper, and
molybdenum, act in a wide variety of enzymatic reactions.
Only very small amounts are needed however, and excess can
sometimes result in ill health, as these can be toxic in high
doses.
Energy
The body needs fuel to power it day by day. Energy is used
up every time the body performs muscular work, such as moving
or even breathing. The most efficient source of energy in
the diet is fat, which is quickly converted by the body into
usable energy. Carbohydrates and proteins are also sources
of energy, but to a smaller extent.
The body can usefully store energy as fatty tissue, and in
times of shortage these will be used up - hence the weight
loss when on a diet.
For the general pet owner,
we can be reasonably confident in the UK that the ingredient analysis
on the bag of food we feed is based upon good practice and current
wisdom regarding the requirements for pets at each stage of their
growth and development.
For European pet food manufacturers, FEDIAF produce guidelines for
the industry, together with latest research on nutritional requirements,
and in the UK the PFMA (Pet Food Manufacturer's Association) do
the same
Nutritional Requirements for Dogs
In the US, dog foods labeled as 'complete and balanced' must meet
standards established by the Association of American Feed Control
Officials (AAFCO) either by meeting a nutrient profile or by passing
a feeding trial.
There is no reason to suppose that American dogs are intrinsically
different to dogs anywhere else in the world, so we'll use their
wisdom as our guide.
There is one nutritional profile given for growth (puppies) and
one for adult maintenance, including recommendations on protein,
fat, fat soluble vitamins, water soluble vitamins, and minerals.
*Although a true requirement for fat per se
has not been established, the minimum level was based on recognition
of fat as a source of essential fatty acids, as a carrier of
fat-soluble vitamins, to enhance palatability, and to supply
an adequate caloric density.
**Because of very poor bioavailability, iron
from carbonate or oxide sources that are added to the diet should
not be considered as components in meeting the minimum nutrient
level.
***Because of very poor bioavailability, copper
from oxide sources that are added to the diet should not be
considered as components in meeting the minimum nutrient level.
****Because processing may destroy up to 90
percent of the thiamin in the diet, allowance in formulation
should be made to ensure the minimum nutrient level is met after
processing.
In the US, cat foods labeled as 'complete and balanced' must meet
standards established by the Association of American Feed Control
Officials (AAFCO) either by meeting a nutrient profile or by passing
a feeding trial.
There is no reason to suppose that American cats are intrinsically
different to dogs anywhere else in the world, so we'll use their
wisdom as our guide.
There is one nutritional profile given for growth (kittens) and
one for adult maintenance, including recommendations on protein,
fat, fat soluble vitamins, water soluble vitamins, and minerals.
Cat food is food manufactured for consumption by cats from the
age range of just a few months. Although cats are obligate carnivores,
most commercial cat food contains both animal and plant material,
supplemented with vitamins, minerals and other nutrients. Cat food
is formulated to address the specific nutritional requirements of
cats, in particular containing the amino acid taurine, as cats cannot
thrive on taurine-deficient food and go blind when fed with dog
food, for example.
*Although a true requirement for fat per se
has not been established, the minimum level was based on recognition
of fat as a source of essential fatty acids, as a carrier of
fat-soluble vitamins, to enhance palatability, and to supply
an adequate caloric density.
**Because of very poor bioavailability, iron
from carbonate or oxide sources that are added to the diet should
not be considered as components in meeting the minimum nutrient
level.
***Because of very poor bioavailability, copper
from oxide sources that are added to the diet should not be
considered as components in meeting the minimum nutrient level.
****Because processing may destroy up to 90
percent of the thiamin in the diet, allowance in formulation
should be made to ensure the minimum nutrient level is met after
processing.
*****Add 10 IU vitamin E above minimum level
per gram of fish oil per kilogram of diet.
******Vitamin K does not need to be added unless
diet contains greater than 25 percent fish on a dry matter basis.
Biotin does not need to be added unless diet
contains antimicrobial or antivitamin compounds.
Methionine may be used to substitute for choline
as a methyl donor at a rate of 3.75 parts for 1 part choline
by weight when methionine exceeds 0.62 percent.
It can be difficult to compare foods because of the moisture content
(i.e. dry diets average 10% water, but moist foods can have 80%
water content) and the fact that labels list levels as an 'as fed'
rather than 'dry matter' basis which would enable customers to directly
compare the different foods.
If you want to convert 'as fed' to 'dry matter' a simple conversion
is necessary. Are you ready?
If a dry food is 10% moisture then it is 90% dry matter (Still
with me?)
If the declared protein content is 20%, then the maths is 20
x (100/90) which gives us the protein on a dry matter basis
of 22%.
Compare this to a canned or pouch food which declares a protein
content of 5%. This food contains 80% moisture (or only 20%
dry matter) so the maths is 5 x (100/20) or 25% protein on a
dry matter basis.
You'll find this with the majority of canned foods, the actual
protein content is higher than that of dry complete foods when compared
on a dry matter basis. You can do the same for fat, fiber, etc.
Pet
Dogs,
however are much more flexible in their aproach to eating and do
not have to consume just meat. However, just because by definition
they are omnivores does not mean that a vegetarian diet alone is
the most appropriate way to feed.
