By Dr. Becker
Today I want to talk about high pressure pasteurization, or HPP, and its controversial role in what we now refer to as "sterile" raw pet food.
High pressure pasteurization is a processing method used by the USDA to eliminate microbes in the food chain. According to Virginia Tech's High Pressure Processing Lab:
"HPP is a non-thermal preservation and pasteurization technique that causes little or no change in the organoleptic and nutritional attributes of the product being processed unlike most conventional heat treatments."
Organoleptic attributes include things like taste, odor, color, and the feel of foods.
The High Pressure Pasteurization Process
The way HPP works is by applying high hydrostatic pressure, which is pressure exerted by a liquid, through a water bath that surrounds the product. The pressure is uniformly applied from all sides and throughout the product, which keeps the food from being crushed.
According to HPP proponents, the process does not cause the foods to undergo significant chemical transformation, but does successfully eliminate all pathogenic microbes from the food, including bacteria such as Listeria, Salmonella, and E. coli.
High pressure pasteurization is USDA-approved, touted as being a 100 percent natural process, and is allowed for use on organic and natural products in both the human and pet food markets.
Is Raw Food That Has Been High Pressure Pasteurized Truly Raw?
Many raw feeders believe HPP is a method of processing whole living food into a modification of whole living food, and that we should not confuse truly unadulterated raw food with raw food that has been processed using HPP.
Depending on the amount of pressure used, research has demonstrated that proteins do denature, and beneficial good bacteria are obliterated during HPP processing. For these reasons, some raw feeders don't feel pet food companies selling HPP-treated diets should be allowed to call them "raw."
Some raw pet food manufacturers have started using HPP for a variety of reasons. I think one of the reasons is they are hoping to increase acceptance of raw diets by the veterinary community.
I also think they want to opt out of the never-ending debate about the potential presence of bacteria and parasites in raw food. They are hoping to appeal to nervous pet owners who want to feed raw with zero risk of bacterial contamination to their pets or themselves.
Some Pets Can Benefit from Sterile Raw Food
There are animals who can benefit from sterile (HPP processed) raw food. These include some pets undergoing chemotherapy. Dogs and cats with significantly compromised immune systems should not be exposed to potential pathogens from any source, including food.
Raw food that has undergone HPP provides these pets with a convenient source of a better-quality food that is also sterile, which is important in reducing the risk to debilitated bodies.
Additionally, many veterinarians feel much more comfortable recommending sterile raw foods for pets with compromised GI defenses. Pets dealing with dysbiosis and inflammatory bowel disease may not have the gut resiliency to handle normal bacteria loads found in some foods. Many of these pets do much better on sterile foods until their gut issues are healed.
So sterile raw foods can be a good compromise for pet parents who want to provide the benefits of raw food to a dog or a cat, for which a true unadulterated raw diet would pose an unacceptable risk to the pet or themselves. We should keep in mind that some pet owners are also immunocompromised or immunosuppressed, but they still wish to feed their pets the best, most optimal diet.
One important point to remember is that HPP treated foods are sterile after processing, but are still susceptible to the same handling and storage issues that face all raw meat products. A half used bag of HPP treated raw food sitting in the refrigerator for four weeks will still pose the same risks as other raw meats. So the handling of HPP treated pet food is no different than the handling of any raw meat product.
Unadulterated Commercial Raw Pet Food: Safer than Canned, Safer than Kibble
I see two unfortunate issues unfolding with the increased use of HPP within the commercial raw food industry.
First, many HPP proponents believe ALL raw foods on the market should be treated with HPP in order to gain acceptance by the traditional veterinary community and pet owners who want to feed raw, but with the reassurance the food is initially bacteria-free.
Number two, a certain percentage of the general public may assume the increased use of HPP is due to issues or problems stemming from unadulterated raw food diets, which is simply untrue.
Most manufacturers of unadulterated (non HPP) raw pet food use high-quality USDA-inspected meats. They also test their products for proper nutrient levels and contaminants, which is why raw meat diets have substantially less potential for high loads of toxins and are typically not the subject of pet food recalls. By contrast, most mass-marketed dry foods, which are regulated by the FDA not the USDA, use rendered and 4-D meats (meats from dead, dying, disabled, and diseased animals).
Because commercially available raw food diets are grain-free and therefore mycotoxin-free... because raw pet food companies use high quality meats sourced from healthy animals... and because they focus on microbially responsible food processing, there's actually a much lower risk of recalls involving unadulterated raw food than there is with commercial kibble.
If your pet is a healthy, thriving dog or cat, then a completely fresh unadulterated raw diet is what I would recommend. There are tremendous nutritional benefits derived from eating non-sterile foods.
Those of you who have been subscribers here for many years know that I always recommend that we mimic Mother Nature when feeding our pets. Given the choice, our dogs and cats would choose to hunt and consume fresh prey -- but they would certainly not be catching sterile prey.
Dogs and cats are designed to efficiently and healthfully process the normal bacteria loads found in their prey. That's also why pets can lick their butts, eat poop, and not die from those behaviors -- they were designed by nature to be able to do such things.
So, what's my take on this up-and-coming hygiene procedure in the pet food industry? I don't see a need for the majority of pets to be fed sterile raw foods, as the majority of pets are not significantly immunocompromised. However, I am thankful that we have some raw food options processed using HPP in the case of animals that cannot handle the normal bacterial load of unadulterated raw food. Feeding HPP-processed raw foods to healthy pets will not harm them, of course, but it's unnecessary.
If you want to know whether the raw food you're buying has been subjected to high pressure pasteurization, try checking the company's website first and if you don't find the information there, you'll need to call the manufacturer to find out.