The salmon used in the Northwest Naturals Chicken & Salmon Raw Dog Recipe and Freeze Dried Salmon Treats is wild caught from Alaska. For human consumption, Wild Pacific caught salmon is preferred. However, salmon from the Northwest can carry the parasite Nanophyetus salmincola that in turn may be infected with Neorickettsia helminthoeca. Since consuming fish infected with Neorickettsiais usually fatal to dogs, all salmon used in our facility is manufactured in accordance to the FDA guidelines for freezing fish to kill parasites.
Northwest Naturals diets are flash frozen -30º at the time of production and then are maintained at -20º until shipped. NW Naturals Chicken & Salmon diet – Salmon uses is Alaska Wild Caught Salmon Below you will find the FDA Guidelines. 4.2. Freezing – Unlike bacteria, molds, and viruses, most parasites are relatively easy to destroy by holding the raw material or finished product at freezing temperatures for a specified period of time; of course, this is dependent upon the internal temperature of the material. The Fish and Fishery Products Hazards and Controls Guide recommends a temperature below -4 oF (-20 oC) for 7 d or -31 oF (-35 oC) (internal) for 15 h to kill the parasites of concern (FDA 1998). Although, based on the data currently available, these recommendations may appear stringent, it is because they were developed for the parasites that are considered most resistant to freezing (G. Hoskin 2001; personal communication; unreferenced). Already in 1975 (Food Chemical News, October 1975) Dr. G. J. Jackson cautioned that the anisakid nematodes vary in their ability to survive at low temperatures. For instance, certain species of anisakids have been reported to survive up to 52 h at -4 oF. A number of other time and temperature regimes have been prescribed to accomplish the inactivation of parasites. Another such option prescribes holding the fish at -10 oF (-23 oC) for 60 h (Ching 1984). Alternatively, E.U. regulations require freezing at a temperature of no more than -4 oF (-20 oC) in all parts of the product for not less than 24 h in order to control parasites in fish. While the parasites can be killed by freezing the finished product, it is generally considered more appropriate to freeze the raw material prior to processing. Nematodes in particular will attempt to depart the gut during processing and will then establish themselves in the muscle during salting or smoking (Hauck 1977). The result may be the presence of nematodes on the surface of the finished product, often perpendicular to the surface. Their presence becomes a quality issue resulting in an aesthetically unwholesome (although safe) product. For this reason, it is a good practice to freeze susceptible raw material, even for hot-smoked fish.