"What additives are in pet foods?" is a question of interest to pet
owners. The purpose of additives (more accurately called "minor
ingredients") includes: providing nutritional benefits, safety and
maintaining the desirable features of colour, flavour, texture,
stability and resistance to spoilage. In short, these "additives" are
included to enhance the quality of the food and to ensure the food
remains in good condition after processing.
The term "additive" can be applied to a range of ingredients that
manufacturers add to the basic raw materials (meats, fish, cereals and
vegetables) that are at the heart of pet foods. These "minor ingredients"
include essential nutrients such as vitamins and minerals, flavours,
colours and agents that are included to prevent harmful spoilage of the
foods due to fats going rancid or through bacterial or fungal
contamination. Let's take a look at some of the important "minor
ingredients" that are included and why they are there.
Vitamins and minerals
Many prepared pet foods are carefully formulated to provide all the
nutrients needed by the dog or cat in the amounts required. During recipe
formulation and cooking, for nutritional completeness, it is important that
key nutrients such as vitamins and minerals are added as required into the
recipe to make sure they are all present in the finished food for the dog
or cat. These foods are "complete and balanced" a statement advising the
food is "nutritionally complete" or similar will be included on the label.
Vitamins are nutrients needed in very small amounts to enable many
functions in the body. In the correct quantities they are absolutely vital
to the health of all animals.
Dogs and cats cannot make all the vitamins they need so these must be
supplied in the diet.
There are two broad vitamin groups:
Fat-soluble vitamins : A, D, E, K, which are
digested and absorbed in a similar way to dietary fat.
Water-soluble vitamins: the B-complex vitamins and
vitamin C, which are absorbed in the small intestine and are
excreted in the urine.
Fat-soluble vitamins can be stored (eg in the liver), while
most water-soluble vitamins cannot.
Minerals are essential for the body's metabolic processes. They are broadly
categorised into two categories: macrominerals, needed in relatively large
amounts (e.g calcium, phosphorus, iron) and microminerals, which are
important but only needed in very small amounts (e.g cobalt, copper).
Sodium is another essential mineral and the major source of dietary sodium
for dogs and cats is salt (sodium chloride). Salt occurs naturally in some
ingredients and is included in pet foods for its nutrient value, but also
as it is a preservative and flavour enhancer.
Pet food safety is of critical importance. Preservatives (including
antioxidants) may be added, largely dependent upon the type of pet food
product and processing, to ensure that food products remain nutritious and
safe for consumption throughout their shelf life. The food must be
protected from bacterial or mould contamination and spoilage and be
protected from degradation and the loss of nutrients during storage. The
method of preservation used depends on the type of food as the type of
processing also contributes to the food integrity and shelf life:
Dry foods: the low moisture content helps to inhibit the
growth of most organisms.
Moist foods: the heat applied in cooking of canned or
foil sachet foods kill microbes and the packaging excludes air,
protecting the food.
Chilled foods: processed chilled foods have undergone
a controlled thermal process and this, together with refrigeration
during storage helps suppress spoilage.
Semi-moist foods: these generally have a low pH and
contain humectants that bind water to the product, making it less
available for use by invading organisms.
Antioxidants are preservatives used to protect foods from deterioration due
to oxidation. Most pet foods contain fats and oils, which need to be
stabilised by including antioxidants to prevent fats from reacting with
oxygen in the air (oxidising) and becoming rancid which leads to losses in
nutritional quality and the accumulation of possibly harmful degradation
substances and unpleasant odours. The inclusion of antioxidants helps to
maintain wholesomeness and quality of the food. Antioxidants are
incorporated into dry foods to protect them from exposure to oxygen after
processing. These are not generally added to canned foods because these are
cooked at high temperatures in the can, thereby "sterilising" the contents
in the sealed, airtight containers. Spoilage can occur if the can is
damaged or if left too long after it is opened. Antioxidant preservatives
that might be included in dry pet foods include: a variety of herbal or
plant extracts including: rosemary extract, citric acid, vitamin E
(tocopherols), vitamin C (ascorbates) or man-made anti-oxidants, which have
been used in various human foods for many years 1.
Antimicrobial agents help protect food from potentially harmful spoilage
organisms including mould formation or bacterial putrefaction. Some fresh
meat products sold for pet consumption include added sulphite preservatives
that release sulphur dioxide to suppress microbial growth and spoilage.
Sulphites have been included in a range of food and beverage products for
humans over many years for a similar purpose. It is known that sulphites
degrade thiamine (vitamin B1) and for this reason, the Australian Standard
(AS 5812 - Manufacturing and marketing of pet food) includes the following
requirement: "Where sulphur dioxide or potassium sulphites are used, the
common, prescribed, proprietary name or the FSANZ Food Standards Code
number shall be included on the label. In this instance, to avoid acute
thiamine deficiency in pets, sufficient thiamine shall be present
throughout the shelf life of a pet food product. If necessary, this may be
achieved by thiamine supplementation". The Australian Standard (AS5812)
requires antioxidants and preservatives to be listed on the statement of
ingredients on pet food labels.
Colouring agents may be added to pet foods to enhance the appearance of the
food. These include a range of naturally occurring food colours , food dyes
or mineral based colours such as iron oxide or titanium dioxide. The
Australian Standard (AS5812) requires food colours to be listed on the
statement of ingredients on pet food labels.
Emulsifiers and stabilisers
Emulsifiers help keep the fat in the food and the water from separating.
Gums, lecithin, glycerine and modified starch are used to prevent
separation of ingredients and to create the gravy or gel in canned, sachet
and other moist pet foods. Food gums include seaweed extracts such as
alginate and carrageenan and seed gums such as guar gum (from the guar
Flavours are used to enhance the palatability in some foods and to provide
product variation. Much of the appeal of prepared pet foods to the dog or
cat stems from the choice of raw materials, such as fish, meat, vegetables
or cereals. As with many foods for humans, the cooking process often
increases the palatability of many foods. Some flavours may be added to
some pet foods and these can be natural flavours such as extracts from fish
or poultry, or agents designed to emulate natural flavours. The Australian
Standard (AS5812) requires flavouring agents to be listed on the statement
of ingredients on pet food labels.
Additives: a summary
"Additives" or "minor ingredients" covers a wide
range of recipe ingredients that are included in
They are important ingredients that are included for very
specific and varied purposes.
These "additives" include expensive food
ingredients such as vitamins and are therefore
incorporated into pet foods when considered
necessary, at the appropriate level to enhance the
quality, appeal and
safety of prepared pet foods.
This article is for general information only:
This information is provided by the PFIAA as general information only. For
advice and information concerning feeding your individual pet, we recommend
that you seek the advice of your veterinarian.
1. [Hilton J.W. Antioxidants: function, types and necessity of
inclusion in pet foods. Can. Vet. J., Vol 30, August 1989.]