The safety of the next 2 controversial ingredients that I'll discuss have been highly debated: synthetic Vitamin K, also known as Menadione or Vitamin K3 and the preservative Ethoxyquin.
Menadione- what is it?
Vitamin K is an important vitamin because it contains clotting factors used to stop bleeding, but Vitamin K does not need to be manufactured synthetically; K1 is naturally found in leafy greens and K2 is produced by bacteria in the intestines. While the synthetic form has been present in animal feeds for many years, the lifespan of livestock is drastically less than our companion pets and there has not been any studies done regarding its safety for long-term use.
However, a study done by Oregon State University has determined that Menadione, as injected for its clotting properties, is dangerous and causes oxidative damage leading to anemia and liver toxicity; the FDA has banned the use of synthetic Vitamin K3 in supplements because of its inherent risks.
What is being done?
As an ingredient that is present in natural sources and that is not required by AAFCO to be included in pet food, it makes sense to ask manufacturers to remove it or not include it at all.
This is what has been asked of Earthborn, and Tuffy's products Natural Planet Organics and PureVita-and they responded quickly, removing the ingredient from all their formulations. You may still see Menadione on the Earthborn's label, but this is because new packaging is very expensive- instead of raising prices on the food to cover the cost of new packaging, they elected to continue to use the old packaging until it ran out. I can certainly agree with this decision; however it would be helpful if they, like Natural Planet Organics and PureVita, a package sticker was produced letting us know that Menadione has indeed been removed
Ethoxyquin- what is it?
I have also asked both Earthborn Holistics and Natural Balance about their fish meals and if they have been preserved with Ethoxyquin- another controversial ingredient that has made its way into pet foods. Ethoxyquin is a chemical that is used as a preservative, a pesticide, and a hardening agent for rubber. It has been used in animal feed for over 45 years, but there is debate regarding its safety and it has since been banned from addition in most human foods. While there haven’t been any official studies that have directly implicated the chemical as the cause of pet illness, the manufacturer of the chemical did conduct a study that showed its association with changes in liver pigment and elevated liver enzymes, of which “the health significance… is unknown” (FDA.gov).
What is being done?
Numerous owner reports associating Ethoxyquin with pet illness led to the FDA to lower the maximum allowed amount in pet food. Although officially circumstantial, there is enough implied evidence against its use that most number of high-quality pet food manufacturers have elected to preserve naturally instead, usually with Vitamin E.
However, there is another way Ethoxyquin can make it into pet food: indirectly added from the fish meal suppliers. When a pet food manufacturer directly uses Ethoxyquin as a preservative it must be included on the package label, and this adds the highest quantity of the chemical to the food. Chemical added from indirect sources (such as the fish meal supplier) is of a much smaller quantity, but is there nonetheless, and is not required to be on the label. Federal regulations require that fish meal be preserved before shipment to manufacturers, and for a while Ethoxyquin was used by the suppliers almost exclusively for this purpose.
But, there are now other non-chemical and more natural alternatives, such as the product Naturox. Fortunately, most pet food manufacturers have acquiesced to public concern about Ethoxyquin and requested their fish meal suppliers to use Naturox or another natural preservative, but this remains a work-in progress as manufacturers are still becoming aware of their natural options. I’ve asked both Earthborn Holistics and Natural Balance about the preservative used by their fish meal suppliers, and have been assured by Natural Balance that they require the use of Naturox. I’m pleased to report that Earthborn Holistics claims their fish meals are Ethoxyquin-free as well.