commercial (meat) pet food consumption hazards

Animal & plant waste from human consumption are the main source for most pet food. Their are some exceptions among extremely conscious brands but be aware for the following hazards.


01 diseased meat tissue in pet food

As a result of an accumulation of rejected material that cannot be used for human consumption after an meat inspector has paid a visit has lead to the standard practice of processing rejected material into food for pets and even feed for herbivorous livestock. Typically diseased tissue includes; damaged and diseased tissue parts cut of off animals during the production line into garbage cans. These garbage cans are periodically emptied and sent to pet food factories. Furthermore, animals that died, are dying, are disabled or diseased during transportation and no longer suitable for human consumption are processed into pet and livestock food. Finally, uteruses and fetuses removed from pregnant animals before slaughter are also processed into pet food. Note that all these materials are full of dangerous bacteria such as endotoxins which is a bacteria that induces inflamation and fever as an immune response. Most commercial pet food tested for these toxins contain them and some in extremely high doses.

Link to book: Strombeck D (2010). Home-prepared diets for dogs and cats. Iowa State Press, University of California, School of Veterinary Medicine.


02 the ingredients behind "meat-meal" & "meat by-products"

By-products and meat-meal are widely used in pet foods. Boosting the crude protein (average grams of proteins to 1 gram of nitrogen) content but providing little nutrition. Dogs can only digest 75% of this type of protein. Ingredients that can meat-meal and by-products consist out of; garbage from grocery stores, grease and spoiled food form restaurants, roadkill to large to be buried, sick farm animals who have died for reasons other than slaughter, food substances unfit for human consumption (e.g. moldy rice, fibers from peanuts hulls, newspapers), euthanized dog's and cats from shelters, pounds, and veterinary clinics, poultry feathers, leather, connective tissues, fecal waste, cattle hair, ground bone, residue of euthanasia solutions, and discards from manufacturing foods with little to no nutritional value (e.g. brewers yeast, rice flower, potato peelings, beet pulp, corn gluten). All ingredients are cooked at temperatures between 104-132 degrees Celsius up to an hour. Then centrifuged, ground en mixed into one meal. 

Link to book: Ann Martin (2001) Protect your pet. troutdale, OR: NewSage Press,11.

03 antibiotic residue in pet food meat

Antibiotics are used continually on factory-farmed animals. the conditions that most farmed animals live in today are so unhealthy and stressful that the animals could not survive the profitable slaughter age without the steady use of antibiotics. Many of these antibiotics remaining in animal-based foods result in drug effects and development of bacterial resistance. The issue of the presence of antibiotic residues in food is intensely debated. Numerous research studies have highlighted the irrational use of antibiotics and the risk of problems with consumer antibiotic resistance, spread by foods with antibiotic residues. The concentration and type of antibiotic found in the form of residues varies depending on the geographical area and the type of food analyzed. Available studies present antibiotic residues in all food groups: meat and meat products, milk and dairy products, eggs, and honey products. Although alarm signals are drawn regarding irrational antibiotic use, exceeding applicable legal requirements are identified.

Link to article: Ghimpețeanu, Oana Mărgărita, Elena Narcisa Pogurschi, Dana Cătălina Popa, Nela Dragomir, Tomița Drăgotoiu, Oana Diana Mihai, and Carmen Daniela Petcu. 2022. "Antibiotic Use in Livestock and Residues in Food—A Public Health Threat: A Review" Foods 11, no. 10: 1430. 

Link to infographic on antibiotic use in the EU:  European Medicines Agency, European Surveillance of Veterinary Antimicrobial Consumption (2017) & Van Boeckel et al. (2015)

04 cancer linked to red meat and processed meat consumption 

The World Health Organization (WHO) urged us to consume less meat in 2015 after warning that eating processed and red meat might increase the risk of cancer.

link to article : The international Agency for Research on Cancer (IARC) (2015) IARC Monographs evaluate consumption of red meat and processed meat.  World Healthy Organization (WHO).

05 illegal growth hormones in pet food meat

The use of hormonal active growth promoters ("hormones") in farm animals can increase the production of veal and beef significantly up to 15%. However, in the different parts of the world the regulation regarding the use of such hormones differs sharply. In the European Union there exists a total ban on such use in contrast to the United States of American where the use of some hormones is authorized under strict conditions. It has to be concluded that in some EU Member States an extended black market exists. In the EU the number of ascertained different illegal "hormones" ranges between about 35 and 55. In the USA the number of legal hormones in total is six. In the EU and in the USA (or anywhere else) there exists no adequate regulatory database with relevant and updated reliable “state of the art” information about the levels of natural and xenobiotic “hormones” in common food commodities of animal origin. Residue analyses are performed with non-edible sample material, often at the farm level.

Link to article: Stephany RW. Hormones in meat: different approaches in the EU and in the USA. APMIS Suppl. 2001;(103):S357-63; discussion S363-4. 


06 toxic heavy metals in pet food meat

Toxic heavy metals such as lead, mercury, cadmium, and arsenic from a variety of processes and products are found in pet food as a result of bioaccumulating up the food chain. Tests of commercial pet foods have found as much as 120 times the upper safe range for humans of mercury, plus dangerous levels of other heavy metals. Kibbles came out the test worse then wet foods. The FDA has received thousands of reports of pet s sickened or killed by heavy metals in pet food.

Link to book: Pitcairn, Richard & Pitcairn, Susan. Dr. Pitcairn’s Complete Guide to Natural Health for Dogs & Cats. Emmaus, PA: Rodale Press.1982: 28. p. 14.


07 bioaccumulation of chemicals in pet food meat

Today there are some 80.000 industrial or man-made chemicals in our environment- in the air, water, soil. These are taken up by plants and animals, but especially in the tissues of livestock fed industrially raised feeds, and then accumulate up the food chain to their highest levels in those who eat the livestock.

Link to book: Pitcairn, Richard & Pitcairn, Susan. Dr. Pitcairn’s Complete Guide to Natural Health for Dogs & Cats. Emmaus, PA: Rodale Press.1982: 28. p. 14.


08 dangerous additives in pet food

Pet food makers may add artificial food coloring to make the food look more attractive for the owner (because dogs and cats do not see color). Standard practice is also to add preservatives to keep the dry food from spoiling for a long time. These chemicals include: Butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propylene glycol, and ethoxyquin. BHA and BHT are added to oils as preservatives. BHA is on the list of known carcinogens and reproductive toxicants and BHT is also a carcinogen and causes kidney and liver damage. Ethoxyquin is a chemical that was first developed for the use of insecticide and pesticide. Later also used in pet foods. The FDA received several reports that the chemical causes allergic reactions, skin problems, major organ failure, discoloring's of the liver, changing liver enzyme levels, behavior problems and cancer. Propylene glycol is a humectant (attracts water) and is a second cousin to anti-freeze (regulator of extreme temperatures). This chemical is a major contributor to feline cardiac disease, overt anemia, reducing red blood cell survival time, and renders red blood cells more susceptible to oxidative damage.

Link to book: Pitcairn, Richard & Pitcairn, Susan. Dr. Pitcairn’s Complete Guide to Natural Health for Dogs & Cats. Emmaus, PA: Rodale Press.1982: 28. p. 17.


09 kibble looses 70% of vitamins within 6 weeks left unsealed

The objective of this research was to determine the effects of processing, diet, and storage conditions on vitamin (vitamin A, vitamin D3, vitamin E, folic acid and thiamine) and omega-3 fatty acid (with an emphasis on eicosapentaenoic acid; EPA 20:5n3, and docosahexaenoic acid; DHA; 22:6n3) retention. In the vitamin premix study, the quantity of vitamins declined by approximately 50% over 6 months storage in ambient conditions (AMB; 20C, 50%RH), and all except folic acid were lost to some degree in stressed shelf life testing (bag left open) (SSLT; 50C, 70% RH) over 6 weeks. In all cases, the concentration of vitamins in food exiting the extruder and dryer were lower than target levels.

Link to article: Mooney, A.J. (2016). Stability of essential nutrients in pet food manufacturing and storage.


10 overdosing on artificial vitamins is the standard

Extrusion processing of petfood usually applies heating starting at 100 ◦C up to 200 ◦C. Even though temperatures above 100◦C are detrimental to naturally occurring fat-soluble  vitamins. The solution for companies having to optimize their process for a better vitamin retention (to meet the fediaf regulations) are very costly. Consequently, instead of optimizing the processing parameters, other solutions are applied such as; overdosing on the amount of artificial vitamins before the extrusion (Tran et al., 2008), in an amount that is known to be lost during the extrusion. Secondly, applying vitamins after extrusion using methods such as dusting, enrobing, spraying or coating (Killeit, 1994), a method associated to cause food safety issues, and might result in a poor distribution of the vitamins. Thirdly, coating the kibbles with a gelatin-, sugar- and hydrocolloid-based matrix in the case of vitamin A and D.

Link to general articlePauline Morin;Alicia Gorman;Leah Lambrakis; (2021). A literature review on vitamin retention during the extrusion of dry pet food . Animal Feed Science and Technology, 

Link to overdosing solutionQuang D Tran; Wouter H Hendriks; Antonius FB van der Poel (2008). Effects of extrusion processing on nutrients in dry pet food. , 88(9), 1487–1493. doi:10.1002/jsfa.3247 

Link to coating solution: Ulrich Killeit, Vitamin retention in extrusion cooking, Food Chemistry, Volume 49, Issue 2, 1994, Pages 149-155.


11 hard food and toys are not beneficial to oral health

Approximately 80% of adult dogs and 70% of adult cats have some form of oral disease. While not all pets are willing to accept tooth brushing it is the gold standard for good oral care.  It does take time to train the pet to accept tooth brushing.  Make sure to have a detailed demonstration for the pet owner such as this. Feeding hard kibble will not keep the teeth of you pet clean. Most dogs and cats actually swallow their kibble whole therefore getting no dental benefit.  Even if the pet chews the kibble, the kibble is too hard and breaks apart when the tooth hits it and offers no benefit.  Neither do bones, chew toys and tennis balls help to keep their teeth clean. The dogs jaw does not shift side to side like a humans therefore when they chow down on a bone they often fracture the carnassial teeth. These fractured teeth hurt and can lead to infections and abscess if left untreated (Wild dogs and wolves often have multiple fractures in their mouths due to chewing on bones). The rough surface of the tennis ball can lead to abrasion, wearing away the enamel or surface of the teeth over time.  Dogs who constantly chew on tennis balls often have severely worn teeth that can lead to a very painful tooth. Finally oral disease is not an inevitable part of aging. Better yet, good oral care can add an average of 2 years to the life of your pet

Link to veterinary dentistry blogMary L. Berg (2019), BS, RVT, RLATG, VTS (Dentistry) Beyond the Crown Veterinary Education Lawrence, KS