We’ve been following the BBC’s ‘Trust Me I’m a vet’ series with some concern.
The first programme highlighted the deficiencies in the mineral content of processed pet foods. ‘Processed’ foods comprise the dry ‘kibbles’ and ‘wet’ cans or pouches that have been subjected to high temperatures and pressures. No raw foods were tested as far as we’re aware. At Cotswold RAW we welcome independent research into the nutritional aspects of dog food although the BBC’s presentation of the results was ill-informed and unbalanced (see footnote article from The Times about bias at the BBC). Professor Gardner at Nottingham University has chosen minerals as the target. Next time we’d encourage him to look at the deficiencies in the key nutritional building blocks of amino acids, essential fatty acids and enzymes. However, his current focus is minerals.
Except for calcium, phosphorous and potassium, minerals are only required by dogs in small, even trace, amounts – measurements are typically in parts per million (equivalent to 1mg/Kg) and even the best laboratories struggle to test to this level of accuracy (EU regulations allow a ‘verification difference’ of 5mg/Kg between two samples and a ‘limit of quantification’ (the lowest concentration at which the mineral can be reliably detected and quantified) of 10 – 20 mg/Kg for the trace minerals). Hence any ‘one off’ test needs to be treated with caution. The Pet Food Manufacturers Association in response to the programme pointed out that Nottingham University isn’t a DEFRA certified testing laboratory, which is true.
One also needs to take account of the parameters against which these tests are performed. Firstly the EU guidelines state that EVERY meal needs to be perfectly balanced, containing all the amino acids, vitamins and minerals down to the last part per million. Humans don’t eat a perfectly balanced meal at every sitting, it’s a balance over time that matters. The reason for this ridiculous requirement is simply that the guidelines have been set by the kibble manufacturers on the assumption that the poor dog will eat their product and nothing else every day of its life – so it had better contain all the nutrients required. Secondly the amounts stipulated are at best educated guesses, relying heavily on the conclusions of the US National Research Council (NRC) and, to some extent, AAFCO (whose guidelines are created in conjunction with the multi-nationals they are there to police). Thirdly, as noted above, the ability of even the best laboratory to sample and measure with such precision is highly questionable. We wonder whether Nottingham could reproduce their results.
So we’re not surprised at the findings that over two thirds of processed foods fail to comply with EU recommended minimum levels. The only surprising thing is that the processed food industry can’t comply with its own guidelines. Processed dog food is manufactured at high temperatures and pressures which basically ‘kill’ most of the nutrients. In order to comply with the regulations these nutrients need to be replaced in the form of artificial additives. All the manufacturers have to do is measure out the correct quantities of the right chemical.
But what are the guidelines? Below are the recommended minima for the twelve minerals that the EU has said are essential for dogs and which were tested by Nottingham University. The numbers are given as amounts per 1,000Kcal of energy contained in the food. This is the best measure as foods can vary in energy content significantly (and a dog will eat enough food to satisfy its energy needs and so it is that amount of food that has to contain the requisite of minerals and other nutrients). We also show for comparison the analysis we carried out last week on a ‘composite’ sample of our most popular raw recipes (beef, lamb, chicken and beef & tripe). Using a composite sample gives a more reliable indication of the nutrients the dog receives over time as we always recommend varying the protein source in the diet (as indeed did the BBC programme) for all sorts of reasons (such as preventing allergies and boredom!).
As noted above the EU relies heavily on the NRC and AAFCO for their guidelines and it’s worth examining how the guidelines were established in the US. Take manganese for example. The NRC acknowledge that –
- • There are no reports of bioavailability of manganese in dogs or cats
- • There are no reports of manganese deficiency in dogs or cats
- • There are no specific reports regarding dietary requirements or allowances of manganese for puppies
They base their recommendation on an analysis of the milk fed by its mother to a puppy at peak lactation – and arrive at the figure of 1.44mg per 1,000Kcal which is absorbed (‘bio-availability’) to the extent of 75-80%. This seems a reasonable place to start. They then estimate that an adult dog would need somewhat less, estimated at 1.2mg, for ‘maintenance’ but don’t have particularly good evidence for this (note that the EU recommended figureis well below the ‘Limit of Quantification’ of 20mg/Kg). However, this recommendation makes a huge assumption about bio-availability of the inorganic manganese, assuming it to be only 10%. If the bio-availability were (say) 75-80%, the same as the mother’s milk for example, then the recommended adult requirement could drop from 1.2mg to 0.16mg – quite a difference! The point is that it is the nutrients that the dog can absorb that matters, not the amount of inorganic chemicals that are added to the mix, the majority of which the dog is unable to absorb.
So now we come to the one mineral in our composite sample that was below the EU guideline – zinc. The FEDIAF guideline was established from US data using research by Meyer which recommended 15mg per 1,000Kcal for adult dogs, based on a bio-availability of 25%. This data was ‘confirmed’ by the Waltham Centre (an establishment funded by a well-known processed food manufacturer). They fed two diets, one containing 50mg of zinc/Kg and the other 200mg/Kg to Labrador puppies and found no difference in the dogs’ development. From this scant data they calculated the recommended amount at 25mg/1,000Kcal for puppies and slightly less for adults at 18mg. Our sample had 16mg/1,000Kcal which is almost exactly the amount recommended by Meyer and is also within the margin for error allowed by the EU Regulations. These may seem small amounts but just to put them into context the recommended daily amount for an adult human male is about a quarter of the EU guideline for dogs
It’s all about absorption again. Several factors influence zinc absorption in dogs, one of which is genetics (northern breeds such as Alaskan Huskies seem to have a genetic inability to absorb zinc) but also foods made from plant material contain phylate and fibre, both of which reduce zinc absorption. Raw foods contain little plant material and zinc absorption is higher as a consequence.
Zinc deficiencies are relatively rare but do occur, most commonly manifested as dermatosis and dogs prone to skin problems may need more zinc but over-dosing will cause problems with calcium absorption (there is actually a legal maximum for zinc content of dog food). A good quality raw diet containing meat and bone (plus a little flax seed and wheat germ) will give your dog all the zinc it needs with no risk of an over-dose.
In summary, the regulations (and testing thereof) really need to consider the dog’s nutritional requirements over time and also address bio-availability. Natural sources of these minerals in raw food are considered to be much more bio-available than the inorganic sources used in processed food. Feed a complete, natural, raw diet, varying the protein source over time and your dog will get all the minerals (and other nutrients) it needs for a healthy and active life.
The second programme contained a scientifically illiterate attack on raw feeding. We would have expected the BBC to provide some unbiased commentary but it did not and one wonders why (it would be interesting to ascertain how the programme was funded). Their big issues were firstly the difficulty in providing a complete and ‘balanced’ diet if feeding raw which may be true for DIY raw feeders but is pretty insulting to the professional producers of complete raw food and secondly that raw food contains bacteria. They demonstrated this by getting a sack of raw meat, of uncertain provenance and age and tested it for bacteria. Of course all raw food is ‘alive’ and contains natural enzymes and bacteria (that’s why raw feeders believe it’s so much better for the dog).
The Petrie dishes showing bacteria from the raw meat looked sensational but the same result would have resulted had the researcher used a chicken that was destined for your Sunday lunch table.
They then mention two categories of bacteria which cause illness in humans (dogs are much more resilient due to their concentrated stomach acid and short digestive tract and are rarely affected), inferring that these came from the raw meat. Salmonella is simply NOT present in ANY commercial dog food. All pet food, be it raw or processed is subjected to the same testing for the complete absence of salmonella. The vets who raised the concern about salmonella really need to go back and do their homework. The second of the harmful bacteria mentioned, campylobacter, is indeed present in over 50% of chicken destined for human consumption. This is accepted by the human food chain (there is no routine test for ‘campy’ in our food chain) and the Food Standards Agency relies upon people being sensible in their handling of raw chicken. Indeed there has been some recent press coverage about how chicken in the USA is ‘sterilised’ with chlorine but tat this is not permitted in the EU. It should also be pointed out that firstly campy is naturally present in the gut of perfectly healthy dogs (88% according to vets at the University of Liverpool, the very institution featured in the BBC programme) and secondly that bacteria don’t reproduce when frozen. For a full analysis of the bacteria issue please read our blog ‘The truth about bacteria’.
Finally, in the BBC program, they test the dogs’ faeces and find that there’s more bacteria in a raw-fed dog than a kibble-fed one. This shows a shocking level of ignorance as a brief review of the study published in February 2017 by the US National Institute of Health would have revealed. This study also examined dogs’ faeces and concluded “the administration of a raw based diet promotes a more balanced growth of bacterial communities and a positive change in the readouts of healthy gut functions in comparison to an extruded diet” In other words, dogs fed raw have a higher degree of biodiversity and a greater proportion of friendly gut flora, evidence of a healthy, functioning gut.
Anyway here at Cotswold RAW we deal with the bacteria issue by sourcing the very best ingredients, using air-tight and leak-proof packaging (as required by the Regulations and, surprisingly, not used by many raw producers) and finally, freezing and packing the healthy food into a natural, totally sterile casing – the unique Cotswold RAW sausage providing ease of handling and portion control.
The third and last programme in the series highlighted the risk of a dog eating the contents of a recycling bin, which contained mouldy bread. This indeed is a risk and it can occur in a dry kibble that has been kept inappropriately. This fact was (of course) not mentioned and it is often brushed under the carpet by pet food manufacturers. Moulds thrive on organic matter in a moist, warm environment. Although the BBC’s case study (in which the dog died) referred to mouldy bread, dog food is organic matter so is susceptible to mould. A balanced programme would have pointed this out stating that whilst dry dog food can be safely stored in an un-opened bag for months, once opened it is exposed to airborne fungal spores, moisture and light which will speed up the growth of mould. Basically, if you must feed kibble, store the bag once opened in a cool dry, preferably air-tight container.
For the scientifically minded, the concern are the mycotoxins found in dog food that contain wheat, corn or rice. Aflatoxin, fumonisin, zearalenone, ochratoxin and the wonderfully named vomitoxin are the most dangerous. They are not only toxic but some attack vital organs, some cause reproductive issues and several are known to be carcinogenic.
Mycotoxin contamination has resulted in several large scale pet food recalls in the USA, most recently in 2012. A list of recalls in the US can be found at www.dogfoodadvisor.com.
Why is it that the BBC didn’t present a balanced view? Firstly because of their poor research but also because the vets themselves are taught that processed food is good and raw is bad. So it’s not all the fault of the BBC.
So the debate continues. Kibble can be cheap and convenient but be aware of the need to keep it properly. Raw food is ‘alive’ so handle it properly – and try the unique Cotswold RAW sausage in its edible, sterile ‘wrapper’