BTW does anyone know whether or not every single batch of raw food destined for pet food is tested for bacteria?
Knowing that manufacturers of pet food need approval from DEFRA to process animal by products (ABPs) into pet food (including raw dog food) is reassuring as (firstly) there are specific categories of food that may not be used - as defined in their guidance. Here is the link: https://www.gov.uk/guidance/animal-by-product-categories-site-approval-hygiene-and-disposal
Of note Category 1 APBs and Category 2 APBs - described and rated as high risk
- reassuringly cannot
be used in pet food. Whereas the definition of category 3 APBs is rated low risk
and may be used.
And (secondly) these DEFRA regulations of 9 October 2014 issue specific information about raw food and reassuringly include that raw foods must be tested
for bacterial infection.
Various quotes from the DEFRA regulations regarding manufacturing raw pet food are as follows:
“You must take samples from raw pet food”
“You must send samples to be tested for:
“Take a separate sample for Salmonella and Enterobacteriaceae from each of your product lines. You must have a different product line for:
• each species of meat or offal that you process
• each species of tripe that you process"
"Each sample should be made up of 10 sub-samples of 30 grams taken randomly from the product line."
"The frequency of sampling will depend on several factors specific to each pet food facility.”
"The Animal and Plant Health Agency (APHA) may ask you to carry out additional tests as one of your operating conditions."
"Your sample will fail if any sub-sample contains any Salmonella colonies"
"A sample of raw pet food will fail if:
any of the sub-samples contains more than 5,000 Enterobacteriaceae colonies per gram
3 or more sub-samples contain more than 10 Enterobacteriaceae colonies per gram"
“Raw pet food must be packaged in clean leak-proof packaging.”
I'm unaware of how many of the species that make up the Enterobacteriaceae family are tested. Suffice to say there is a helpful section on identification of Bacteria, in the “UK Standards for Microbiology Investigations”, issued by Public Health England dated 13 April 2015. Notably, the “bacterial family Enterobacteriaceae currently has 53 genera” (groups) and of these, “26 genera are known to be associated with infections in humans”.
So as well as testing specifically for Salmonella, it's this particular family of bacteria (Enterobacteriaceae) that is tested, yet which specific of the 170+ known species is unclear.