Home > Pawspectives: ProDog’s Blog > Nutrition > The Concerning Ingredient in Processed Pet Foods: Not Mentioned on the Label

The Concerning Ingredient in Processed Pet Foods: Not Mentioned on the Label

The Concerning Ingredient in Processed Pet Foods: Not Mentioned on the Label

A 5-minute read, written by Caroline Griffith: Pet Industry Nutrition Consultant

Did you know carcinogenic compounds are added to processed pet food?

Have you heard of Sodium Nitrites or Nitrates?:

These are compounds added to many pet foods to give the pinkish or reddish colours we like to see. The colours usually make us feel as if the food is meatier.

The practice of adding them is more commonly seen in brands that have coloured kibbles or wet pet foods that look that colour. However, as you will read, they are of concern in all processed foods, even the plain brown varieties.

In human intended foods, they are found primarily on processed meats, cured meats or smoked meats. Nitrates are also included as a form of preservative. They can be labelled as Natural preservatives, despite the potential health concerns with them.

You see, Sodium Nitrites or Nitrates were re-classified as Carcinogenic (at the same level as Tobacco!) by the World Health Organisation (WHO) in 2015 (1).

What’s worrying for our pets is that currently, no known measurement tools are used within the pet food manufacturing industry to present any data on the volume of Sodium Nitrites in the different brands of pet foods (2).

The Nitrates are not disclosed on ingredient lists as they are currently permitted additives.

They are added at known volumes, but the volume contained in the end result, as fed by you, is not measured. No one is checking, or even has a way of checking yet*, how much of this concerning preservative and colourant each processed food has in it!

It is known that some Nitrates are present in foods as Nitric Oxide and some as a converted type known as Nitrosamines.

Nitrate Oxide isn’t as harmful. It’s the converted form Nitrosamines that WHO (World Health Organisation) want us to avoid. Beetroot, for instance, holds a healthy volume and the healthier version of Nitric Oxide (note the similar red/pink pigment). 

While bacteria in our human mouths and acid in our stomachs can convert Nitric oxide to unhealthy Nitrosamines, nature has cleverly got our back by making sure lots of the nutrients needed to counteract this are present in the same plant foods. This isn’t the case with meat or processed dog foods. 

As with humans, a healthy microbiome also contributes to the ability to counteract any Nitrosamines created naturally in a dogs mouth. As many of us know healthy microbiome is an ongoing consideration in the modern world, with so many factors influencing it. Of course, processed dog food is known to negatively influence it (3) .

Nitrosamines are still present in non-coloured dog foods too!

Interestingly, for dog food, Nitrosamines are created when heat is used in the processing of a food and when meat, or a higher protein than most plants contain, is present. As processed dog foods fulfil both those categories, it is safe to say that coupled with the lack of measurement of them; there are likely to be far too many!

The story got more interesting for dog owners when research delved into the dangers of Nitrites/Nitrosamines and their contribution to Cancers.

Studies indicate that both mouth bacteria and the stomach acid are involved in ensuring the Nitrites are converted back into the healthier form, rather than the Nitrosamine form.

‘’New findings: The microbial community found in gastric carcinoma has increased Nitrosating functions consistent with increased genotoxic potential‘’.

The same bacteria, found to be less abundant in raw fed dogs and more abundant in kibble fed dogs, are involved with the conversions to the unhealthy version. (4)

The study also shows that lack of microbiome diversity plays a role, as it also appears to in various conditions such as skin or digestive complaints (all supported by studies I have written about before.)

The gastric carcinoma microbiota was characterised by reduced microbial diversity.”

Bacteriodetes (soil-based microbiome) showed useful in creating the healthy Oxide versions of the Nitrates; they were lower in the cancer patients.

the gastric carcinoma microbiota had an over-representation of Actinobacteria (P<0.001) and Firmicutes (P=0.040), and lower abundance of Bacteroidetes (P=0.003)”.

Studies also mention the link between the use of gastric-acid suppressive drugs in high levels of Nitrosamine. Such drugs are becoming more commonly prescribed in veterinary medicine.

‘’ What we already know: Gastric acid reduction by acid-suppressive drugs results in bacterial overgrowth and high levels of gastric nitrite and N-nitrosamine.’’

To round up…

  • Nitrites and especially Nitrosamines are known Carcinogens and are currently added to pet foods. 
  • They are not even measured for possible safe adjustment, or even simply knowledge, of their levels!
  • Dogs with less diverse, less soil-based microbiome abundance are more likely to have problems with Nitrites in food, potentially cancer.
  • Some plant material, high antioxidant, polyphenol herbs or berries can benefit dogs, especially dogs on processed foods.
  • Both dry and wet-processed foods are at risk due to the heat protein reactions; those that are coloured also have them added on top of that!

Finally, real food is the way forward!

Raw dog food is, of course, the easiest way to provide all the minerals and nutrients your dog needs, but even home-cooked meat and Phyto-nutrition is an excellent option. Just make sure you seek the support of a pet nutrition consultant to ensure your dog is getting the nutrients that bone provides for them too.

By Caroline Griffith | Author: The Best Dog Diet Ever & Imperfectly Natural Canine

Pet Industry Nutrition Consultant | Naked Dog Nutrition Centre





2 Report Fediaf Additives and Undesirable Substances Group Jan 21




4 The fecal microbiome and metabolome differs between dogs fed Bones and Raw Food (BARF) diets and dogs fed commercial diets

Gastric microbial community profiling reveals a dysbiotic cancer-associated microbiota.


*Correct at time of press; lets hope a new way is put forward in years to come.




Caroline Griffith

Author | Pet Industry Nutrition Consultant | Founder of Canine Flow \ Canine Mystery School


Leave a Reply

Your email address will not be published. Required fields are marked *