Are Commercial Pet Food Preservatives Dangerous?

Are Commercial Pet Food Preservatives Dangerous?

Ron Hines DVM PhD

Cooking your pet’s meals at home  

 Health issues sometimes associated with store-bought pet foods  

What  if we can’t seem to loose the weight?

 I’m a vegetarian or a vegan. Shouldn’t my cat and dog be one too?   

Why Do Pet Food Companies Add These Products?

Pet foods that are sold in cans, rely on the sterility of the can to protect them from spoilage in deterioration of the ingredients. But pet foods that are sold dry in bags rely on chemical preservatives to prevent spoilage.

What Are Some Common Pet Food Preservatives ?

One of the ingredients most susceptible to spoilage (oxidation) is fat. Commonly used preservatives in the pet food industry include BHA,   BHT,   TBHQ,   ethoxyquin,   propyl gallate,   benzoic acid,  sodium benzoate,   potassium benzoate ,   sodium nitrate,    propylene glycol and tocopherols.

If those Preservative Ingredients Are Not Listed On The Bag, Does That Mean The Product Is Free Of Them ?


Even brands marketed as “all natural” and “preservative-free” are likely to contain some of these compounds if any of the ingredients are of less than human supermarket quality. Manufacturers that do not, themselves, add preservatives to their product can lawfully claim their product is “preservative free”. But their suppliers of raw sub-ingredients are under no such obligation. (read here)

What Are Some Of The Potential Dangers Of Food Preservatives?

The compounds I have mentioned prevent, spoilage, and microorganism growth by interfering with cell metabolism in one way or the other. Your pet’s body cells share many of the processes found in these microorganisms. What one hopes is that the amounts found in pet foods are not enough to damage the body. You can read about their potential to damage the body  here . When those compounds are tested by the FDA or the EFSA, the tests are for acute (immediate) toxicity, not for the long term, chronic effect of eating small amounts of these chemicals day-after-day, year-after-year.

Triad Disease Of Cats

Cats, in particular, are susceptible to chronic inflammatory conditions of their digestive tract and its surrounding organs. With time, this chronic inflammation sometimes progress to cancer. The problem is called triad disease when liver and gall bladder signs predominate; but inflammatory bowel disease (IBD) and chronic pancreatitis are probably part of the same inflammatory complex. You can read my article about that problem, cholangiohepatitis here . Diet and dietary ingredients may well be one cause of this – it is thought to be so in humans. (read here) Cats are also particularly sensitive to benzoic acid and propylene glycol. (read here & here)

It is true that in most cases, the presence of preservatives at very low levels cause no immediate health problems in your pet. However, there is another issue that pet food companies and the FDA do not address. What is the effect of these chemicals on the life-sustaining microorganisms in your pet’s digestive system? You can read about those important “Back Seat Driver” organisms here.

Spoilage occurs in two ways, natural oxidation of ingredients and bacterial deterioration. Common food preservatives inhibit both these processes. In the process (similar to that of antibiotics) they also kill bacteria essential for good health. (read here)

Physicians have come to realize that a lack of good bacteria allows bad bacteria to prosper. You can read about an increasingly common human disease caused by that problem here. Replacing those lost “good” bacteria (gut flora) helps those patients overcome their illness. (read here) I do not know of any studies that determine the health effects on pets that do not have there complete gut flora. So far, the negative effects have only been studied in simpler life forms and theorized in humans and our dogs and cats. You can read about their importance to a healthy immune system here and here.

What Is The Best Thing For Me To Do?

I believe that the safest thing you can do is purchase the individual components of a healthy dog and cat’s diet and prepare your pet’s meals at home. Supermarket isle and big box retail dog and cat foods pass through too many hands and the precautions taken to keep them free from contaminants are considerably less than what you buy on the human food isles. Read about that here.

Obtaining unbiased information regarding health risks related to what you feed your dog or cat is difficult. You are not going to get it from pet food manufacturers or the “studies” they support. For instance, cats are known to be much less efficient in processing the high carbohydrate content of their cat diets than dogs are. However carbohydrates are cheap. High carbohydrate diets earn cat food manufacturers considerably more profit than high meat diets would. As public awareness of the high carbohydrates content of commercial cat foods becomes common knowledge, major cat food manufacturers such as Nestle PurinaHills/Colgate-Palmolive and Mars PetCare  (= PedigreeWhiskasNutro and Royal Canin) push back. (read here &  here)

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