Feed Your Dog This Not That: Preservatives

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Preservatives are, unfortunately, a critical component in most pet foods, especially the dry variety.  A bag of dog food might not actually be purchased and opened by the consumer for 6-9 months or longer due to the industry’s long (slow) supply chain.  As a result, dog foods must have relatively long shelf lives, often exceeding a year.  The upshot of all of this is that dog foods, and in particular dry foods, must contain some form of preservatives to keep the food stable and edible for its entire anticipated shelf life.


Preservatives that are used in dog food are primarily meant to keep the food in the unopened bag (or other packaging) from going bad.  The estimated shelf life of a food is indicated by the “use by” or “expiration” date that is stamped on the packaging.  The idea is that as long as the package is unopened, the food will remain fresh up thought that date.


What many consumers don’t know is that once the package is opened, the food will begin to deteriorate nutritionally, no matter how far in the future the “use by” date is.  As soon as the package is opened, the food will begin to lose potency, the fats will oxidize, and the food will spoil at a fairly rapid rate.  Keep this in mind when choosing your dog’s bag size.  Some pet experts, like Steve Brown, believe that an opened bag will only last about a week.  Others take a more moderate view and suggest that an opened bag will last about 3 weeks before losing nutritional potency.
Feed this Not that_preservatives

In any case, preservatives are an important part of a dog food recipe.  And like all most types of ingredients, not all preservatives are created equal.   Many preservatives are artificially created chemicals that really have no business being in dog food.  Luckily, there are some healthier choices that can be used as preservatives that are natural and can even offer nutritional and taste benefits to the recipe.  The table below provides some examples of preservatives that are OK to feed a dog, as well as some that are not at all appropriate (or even safe).


Preservatives in Dog Food

Feed This Not That
Mixed Tocopherols (Vitamin E) Ethoxyquin – this is a pesticide and has been linked to cancer
Vitamin C, Acerola Propylene glycol- this is an ingredient in anti-freeze
Rosemary (and extract) BHA & BHT– both are suspected of being cancer causing.
Sage (and extract) Tertiary Butylhydroquinone (TBHQ )- a form of butane used for varnish + resins
Clove (and extract) Sodium Metabisulphite- a bleaching agent


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  1. Now I have to go home and make sure none of the bad stuff is in anything I have for B! Thank you!

  2. Love the Feed This, Not That table. One of the downsides of feeding a raw diet is the waste, because I don’t use preservatives. When I first started feeding raw, I did a crappy job of keeping on top of the food and making sure I didn’t thaw too much. I have a great system now, but it’s pretty involved.

    One of the ingredients that put me on the path to feeding raw was the Ethoxyquin that was rumored to be an ingredient in Blue Buffalo four or five years ago. Today, I know a little more and realized that I was reading blogs, not news reports when I read about that ingredient so I’m not sure how accurate they were, but I’m glad that it opened my eyes to pet food ingredients.
    Kimberly Gauthier recently posted…Is SILEO Safe for Dogs with Fear and Anxiety?My Profile

  3. We try to limit preservatives when we can, even some of our treats these days are kept in the fridge or freezer, and our food is eaten in less than three weeks. We are always astonished at how many people buy a huge food bag to last a few months and on top of that they leave it sitting around open somewhere. Not a good plan.
    Emma recently posted…Visiting The Mississippi River In Minneapolis And St. PaulMy Profile

  4. The life of an opened bag of dog food is frightening when you think about the ginormous bags some folks lug home from the super stores. Ugh!
    M. K. Clinton recently posted…Why You Should Enter Blog ContestsMy Profile

  5. Since that big poison-food scare back in 2007 opened my eyes to preservatives and the like. And, even as early as 2005 when Callie and Shadow were both still puppies, the gal who taught their obedience training class at our local PetSmart warned me about the preservatives used on rawhide chews. “If you have to wash your hands every time you just pull one of those things out of the bag, your girls don’t need to be chewing on them.” That one statement made a lasting impression on me, that’s for sure. From that day forward, my dogs have not had a rawhide – or any other preserved chew toy – in their mouth or even within reach of their paws.
    Callie, Shadow, and Ducky’s Mom recently posted…Wags and Waves for ForrestMy Profile

  6. Thank you for breaking down the preservatives aspect of dogfood. Excellent and useful info!

  7. Timely information – I’m trying to learn as much as I can about treats. While a large percentage of their treats are fresh and/or homemade #sortof I still purchase some, and I get so confused with all the label mumbo-jumbo listed on the back. Thanks so much for this post!
    Groovy Goldendoodles recently posted…I MISS MY DOG – GRIEVING LOSSMy Profile

  8. This is great information. I think BHA and BHT as well as mixed tocopherols are ones I see at times and didn’t know they were good or bad.
    Jan K recently posted…My Sweet BoyMy Profile

  9. Great information.
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