Making safe and nutritious pet foods relies on the same principles as human foods – clean facilities, quality ingredients and appropriate cooking and storage. Pet foods that are sealed into cans, trays or foil sachets and processed using high temperatures, do not require additional additives to preserve the food. Dry pet foods are usually heat processed and dried and these will often include either a natural or man-made ‘antioxidant’. These are added to stop the fats in the food interacting with the air and becoming ‘rancid’, which spoils the food. Some, but not all, ‘chilled’ (refrigerated) pet foods may include food preservatives such as Sulphur Dioxide (sulphites) during manufacture to reduce bacterial spoilage and when added, the Australian Standard for the manufacture and marketing of pet food (AS5812) requires the addition to be advised on the label.
Production facilities, raw materials, processing and preservatives
Making nutritious and safe pet foods involves following the same principles that we adopt in preparing food safely in our own kitchens. Good food relies on quality, fresh ingredients, hygienic processing and appropriate storage of food throughout the production process. Where food additives are used, these are included for a reason – often food safety or nutritional integrity, such as the inclusion of additional vitamins and minerals.
Processing pet foods to reduce the risk of spoilage and to extend shelf life is a very important part of making good quality, safe pet foods. Most prepared pet foods, including cans, trays or sachets, dry foods and ‘pet rolls’ achieve this primarily by undergoing various forms of cooking and/or drying to greatly reduce the risk of microbial contamination and enable the finished product to have an extended shelf life.
Pet foods that are subjected to high temperature processing and then packed into airtight packaging, such as cans and foil sachets are commercially sterile, meaning that there are no live bacteria present. These types of foods usually have a long “shelf life” or “best before” date and do not require additional preservatives to be added during processing.
It is important that retailers and pet owners store all pet foods correctly to avoid spoilage and to feed the pet food within the “shelf life” or stated “best before” date on the packaging.
Stopping fats from going rancid
In making dry pet foods, it is important to prevent fats turning rancid (which occurs when the fats react with oxygen in the air), which can cause bad odours and impact on the taste for the pet. Stabilising the fats included in the food to prevent excessive oxidation is usually achieved by the inclusion of “antioxidants” that can be combinations of naturally occurring antioxidants from various herbs, fruit extracts and vitamins or synthetic versions that are highly effective and safe.
Preventing moulds and yeast
Moulds can proliferate under certain environmental conditions and are recognised to present a possible risk to pet health, so ingredients may be included in dry pet foods to prevent mould growth. An example of such additives are sorbates, which are used in a variety of processed foods and beverages for human consumption, as well as some dry pet foods to inhibit the growth of moulds and yeast, reducing the risk of food contamination and pet illness.
Limiting bacterial growth
Preventing microbial growth and spoilage in pet foods is very important and starts with maintaining a clean manufacturing environment and the choice, storage, testing and handling of good quality raw materials, particularly meat, fish and poultry. Cleanliness and good manufacturing procedures are important in minimising bacterial contamination and overgrowth.
Heat processing of commercial prepared pet foods is a further critical element in suppressing microbe growth. The Australian Standard for the manufacturing and marketing of pet food (AS5812) provides guidance in regard to appropriate management of raw materials, environmental cleanliness and processing of pet foods. Sulphur dioxide (SO2) is a food additive that is approved for use in a variety of human foods and some alcoholic beverages that is highly effective at suppressing the growth of certain types of potentially harmful bacteria and it is usually added as a salt or “sulphite” ( such as potassium sulphite) that then releases SO2 into the food over time.
In Australian pet foods, sulphites are not added during the production of canned, trays, sachets, dry pet foods and many refrigerated (chilled) pet foods, as many of these, such as ‘dog roll’ style products have also undergone a cooking process.
The major pet food type where sulphites are more commonly included are in some, but not all, uncooked or “raw”, refrigerated pet foods. Where sulphites are included during the manufacturing process, the Australian Standard requires that this be declared on the label (see next section). While sulphites are recognised to be effective preservatives, they also have the potential to substantially reduce the amount of an important vitamin, thiamine (Vitamin B1), in pet food.
Thiamine is very important to the health of dogs and cats and is vital to the health of the nervous system, especially the brain. If sulphite-based preservatives are used in pet food production, care needs to be taken by the pet food producer to ensure that there is sufficient thiamine included in the pet food for the duration of the shelf life of the product. PFIAA member companies that are producing pet foods understand the importance of thiamine in pet nutrition. These companies recognise that it is important to limit the amount of sulphite added and to ensure sufficient thiamine in their recipes to offset the adverse impact of preservatives or heat processing on thiamine availability in the finished pet foods.
Research undertaken in Queensland over recent years funded by the federal government in conjunction with industry has provided further valuable information about the extent of thiamine depletion in the presence of SO2 in game meat and this research report is available to assist fresh pet food producers using game meat to include sufficient supplemental thiamine to meet the pet’s needs for the duration of the food’s shelf life.
Labelling and the Australian Standard
The Australian Standard for the manufacturing and marketing of pet food (AS5812) includes a requirement (section 3.1.10) that where sulphites preservatives have been used in producing foods for pets, the name or the Food Standards (FSANZ) code number for SO2 or sulphite shall be included on the label and that “sufficient thiamine will be present throughout the shelf life of a pet food product to ensure that the product is not deficient in thiamine according to AAFCO Official publication guidelines”.
Over recent years there have been a number of research initiatives funded by both government and private industry seeking to develop alternative food preservatives to sulphites for use in pet foods and human foods.
Pet food companies who are members of the Pet Food Industry Association of Australia (PFIAA) provide a wide range of products and flavours to satisfy the needs and preferences of pets and their owners. These pet food companies include carefully selected ingredients and highly controlled processing to provide foods that are nutritious, safe and palatable to all pets whatever their tastes.
This article is for general information only
This information is provided by the PFIAA as general information only. This article has been developed using information from 3rd party public domain information that PFIAA believes to be accurate and authoritative. For advice and more specific information concerning treatment and feeding of your individual pet, we recommend that you seek the advice of your veterinarian.