Are there good fats and bad fats for dogs and cats?
Certain fats, called essential fatty acids (EFA) (also commonly known as omega 3 and 6 oils) cannot be made by our fur kids and therefore must be obtained from food. These essential fats and oils are important in controlling inflammation, blood clotting, and brain development and too little can lead to health problems.
Some oils, when consumed in moderation, can be beneficial for your fur kids and some food manufacturers have them added as part of their recipe. Common nutritious oil supplements include fish oils, evening primrose oil, borage oil and rosemary oil.
Fats also make diets more palatable (diets high in fats taste good). Excess concentrations of “bad” fats can lead to obesity, hepatic lipidosis (fatty liver disease), and “pancreatitis“. Cholesterol is a common animal fat. While excess cholesterol can cause problems in huumans, the same is not true for our fur kids. Recent research reveal that every person and animal needs some cholesterol. Cholesterol is important because important hormones (testosterone, progesterone, estrogen) are made from cholesterol.
It is important to remember that when we discuss oils and fat in this post, we discuss these in terms of real and whole food. Real fats and oils from animal sources, as these are qualified as “good fats and oils” based on our current understanding of the topic.
While fats are essential and many can be beneficial, others can be harmful and too much of any “bad” fat can lead to obesity and the host of health problems that often come with it, most typically in huumans. Many commercial pet food manufacturers add large amounts of low grade, highly processed fats (usually just referred to as ‘oils and fats’, ‘vegetable oils’ or ‘animal fats’) to make the food more palatable. Unfortunately, these fats tend to contain large amounts of saturated and hydrogenated fats which may contribute to disease.
Did you know? Vegetable Oils and Fats are NOT the same as fats derived from animal sources? In fact, vegetable oils are typically not even made from vegetables, but instead from seeds? Vegetable oil contains the highest levels of polyunsaturated fats compared with olive, coconut, and canola oil, and made from oilseeds, legumes, nuts, or the flesh of some fruits. These are extracted from plants using either a chemical solvent or oil mill. Then they are often purified, refined and sometimes chemically altered.
- Energy – major source;
- Storage – stores more than twice as much energy as carbohydrates for the same mass;
- Absorption of fat-soluble vitamins – A, D, E and K;
- Provision of essential fatty oils (EFAs);
- Formation of cell walls, thereby providing structural support;
- Protection of internal organs, e.g. fat pads around the kidneys;
- Insulation – fat layer under the skin;
- Waterproofing – secretion from sebaceous glands;
- Improved palatability of food;
- Manufacture of eicosanoids;
- Some hormones, e.g. aldosterone and prostaglandins.
Although excess fat is a more common problem, deficiencies can also cause problems, e.g. poor coat and skin conditions and reproductive failure.
Vegetable oils based on, or made from, Soybean oil, Canola oil, Corn oil, Cottonseed oil, Sunflower oil, Peanut oil, Sesame oil, Rice bran oil, are said to be “bad” due to their high omega-6 content. Many commercial vegetable oils may also contain trans fats, which form when the oils are hydrogenated. A high intake of trans fat is associated with all sorts of chronic diseases, including cardiovascular disease, obesity, cancer and diabetes 1.
An essential fatty acid is one that must be supplied in the diet because it cannot be manufactured by the body. The essential fatty acid for dogs is linoleic acid. Essential fatty acids for cats are linoleic acid and arachidonic acid. Some researchers believe alpha linolenic acid is also essential for dogs and cats. Essential fatty acids aren’t the only essential nutrient. There are about 50 nutrients or factors essential for good health: 20-21 minerals; 13 vitamins; 8-10 amino acids; two fatty acids. Pets also need fiber, friendly intestinal bacteria (probiotics), and digestive enzymes.
Did you know? Both Omega 3 fatty acids and Omega 6 fatty acids are essential for health. Pets with allergic (flea allergy dermatitis), auto-immune (pemphigus, rheumatoid arthritis), or inflammatory (arthritis, glomerulonephritis) conditions need more Omega 3 fatty acids. Pets that have chronic illness (FIV, FIP, cancer) need more Omega 6 fatty acids.
Omega 3 fatty acids and Omega 6 fatty acids are both incorporated into cell membranes throughout the body. When the cell membranes are damaged, fatty acids are released. Released Omega 6 fatty acids are 10-100 times more likely to promote inflammation than are Omega 3 fatty acids. Inflammation is beneficial if there is an infection your pet needs to fight. Most pets, however, have health problems caused by too much inflammation (flea allergies, arthritis, auto-immune disease), so most pets benefit from supplements with higher concentrations of Omega 3 fatty acids.
Why then, a natural diet?
Not every fat or oil is good for our fur kids. The source, quality, and quantity of fat needs to be carefully considered when choosing a quality dog food. Low fat diets for dogs, less than 5 percent of dry matter total fat and 1 percent essential linoleic acid, leads to dry, scaly skin and harsh coats. In contrast, high fat content not based on real animal sources, introduced abruptly also may cause problems, including all sorts of chronic diseases, including cardiovascular disease, obesity, cancer and diabetes. Undigested fat causes steatorrhea (see: Wikipedia). Excess dietary fat reduces food consumption, which can cause deficiency of other nutrients unless their dietary levels increase. Too much fat in the diet results in your fur kids eating less. Protein, iodine and thiamin levels should especially be augmented when “bad” dietary fat increases.
Excess “bad” fat consumption is likely to cause obesity, a very real, severe and debilitating illness. There are no clearly defined optimal ranges for dietary fat levels in canine nutrition today. A minimum recommendation of 5 percent is currently the industry accepted standard. However, the ranges preferred by most pet owners involved with breeding and show dogs or working dogs are considerably higher (15 to 35 percent of dry matter). The normal dog requires linoleic acid ata dietary level of about 1 percent (this is about 2 percent of the calories). Cats have the same requirement. In addition, cats need a source of arachidonic acid. Linoleic acid does not provide that source. Based on current commercial research, dogs can eat a “meat-free diet” and receive their nutritional requirements for all unsaturated fatty acids, not that this is at ALL recommended, and we discuss this topic in great detail. Cats must eat meat to obtain their arachidonic acid requirements. There are few exceptions, notably borage oil, red current seed oil and evening primrose oil which contain arachidonic acid.
Requirements for a High-Fat Diet?
As noted by Dr. Donald Strombeck, DVM, PhD in his book titled Home-Prepared Dog and Cat Diets, high fat diets are important for some dogs. Milk fat is the most important source of calories for unweaned animals. Bitch’s milk contains about 10 percent fat, which is much greater than cow’s milk. Puppies double their body weight rapidly and need calories to sustain that growth and activity. Fat content of queen’s milk is greater than cow’s milk but much less than that of the dog. With fats providing caloric needs, carbohydrates are less important for energy. Lactose in milk is tolerated well unless for some reason there is insufficient intestinal lactase activity. Many large breeds do not receive enough calories from poorly digested McKibble and McCan. They lose weight or are unable to gain weight no matter how much they eat, but this may also be due to the McKibble and McCan diets. Dogs working at strenuous activities, such as sled dogs, maintain normal weight by eating high-caloric dense diets.
Problems With Feeding a High-Fat Diet?
High fat (good fat) diets are relatively safe for dogs and cats. Feeding a high fat diet is thought to cause acute pancreatitis, but that has not been proven scientifically yet. However, many dogs with pancreatitis have a history of eating a fat-rich meal or raiding garbage containing fatty meat scraps, conversely, most normal dogs fed a 70 percent fat diet do not develop acute pancreatitis. Some working dogs consume that amount in raw. High fat diets cause problems in animals with maldigestion or malabsorption where unabsorbed fat enters the colon; normally little to no fat reaches this point. Bacteria that normally live in the colon, transform dietary fats to fatty compounds that are essentially the same as the active ingredient in castor oil (ricinoleic acid). Bacteria can make one small change in normal fat and convert it to a potent laxative. Ricinoleic-like compounds damage the colonic mucosa, stimulate colonic water secretion, and stimulate intestinal motility, all of which contribute to diarrhea. Therefore, most diets recommended for the management of chronic diarrhea are low in fat, even for dogs and cats with no loss in their ability to digest and absorb fats. In a recent study 2 a 13 week of High-Fat, High-Fructose Diet (HFFD) feeding was associated with an inability of the liver to switch from net glucose output to net glucose uptake despite hyperinsulinemia, hyperglycemia, and portal glucose delivery. The functional consequences observed following HFFD on hepatic glucose metabolism were similar to those observed in diabetic individuals.
Dietary Fats and Palatability
Dietary fat is important for enhancing palatability in McKibble and McCan, and why it often leverage vegetable oils for this purpose. Normally, “low fat” diets are unpalatable. In general, the pet food industry works harder to improve palatability more than anything else. For dogs and cats the most important nutritional problem today is not any nutritional deficiency but obesity. Feeding diets with greater palatability and neutering the pet further contribute to the problem. Dogs and cats that once ate to satisfy their caloric needs now eat to satisfy their appetite.
Dr. John Bauer, a leading veterinary nutritionist, wrote, “Omega-3 fatty acids are critically important in pet neuromuscular development, skin health, and coat quality.“
Sardines are rich in vitamins and minerals. Sardines, or pilchards, are common names used to refer to various small, oily fish within the herring family of Clupeidae. The terms sardine and pilchard are not precise, and what is meant depends on the region. The United Kingdom’s Sea Fish Industry Authority, for example, classifies sardines as young pilchards. One criterion suggests fish shorter in length than 15 cm (6 in) are sardines, and larger ones pilchards. A small serving of sardines once a day can provide 13 percent of vitamin B2; roughly one-quarter of niacin; and about 150 percent of the recommended daily value of vitamin B12. All B vitamins help to support proper nervous system function and are used for energy metabolism, or converting food into energy. Also, sardines are high in the major minerals such as phosphorus, calcium, potassium, and some trace minerals including iron and selenium. Sardines are also a natural source of marine omega-3 fatty acids.
The Omega Health Care System
Dr. Albert S.Townshend, DVM, published an interesting article he titled “The Omega Health Care System” whilst still running his own practice, that is still relevant today.
In the article (no longer available online), he stated that research indicates that there are significant benefits to enriching your pet’s diet with omega-6 and omega-3 fatty acids. He highlighted that few pet foods make an effort to provide these beneficial fatty acids in the proper amounts or the proper ratio.
Omega-6 fatty acids are common in most commercial pet foods. They are derived from plant sources such as corn and safflower oils. They are considered pro-inflammatory, immunosuppressive and pro-aggregatory (Reinhart GA. Review of Omega-3 fatty acids and dietary influences on tissue concentrations. In Recent Advances in Canine and Feline Nutritional Research Vol 3) referenced in “Functional foods and nutraceuticals for cats and dogs” by Rutherfurd-Markwick et al 3.
Omega-3 fatty acids are far less common in commercial pet foods as they are derived from more expensive ingredients such as flax seed and cold-water fish oils and fish meals. They are considered less inflammatory, anti-aggregatory, and vasodilatory and are not immunosuppressive (Reinhart GA. Review of Omega-3 fatty acids and dietary influences on tissue concentrations. In Recent Advances in Canine and Feline Nutritional Research Vol 3 ((The Iams Company, Lewisburg, OH.) (PDF)).
In order for there to be maximum benefit from these fatty acids they must be in a proper ratio to one another 4. A ratio between 5:1 and 10:1, that is, a ratio of 5 or 10 parts omega-6 to 1 part omega-3 fatty acids is ideal and produces the maximum benefit based on his observations. It should be noted that these ratio change, as science itself is fluid. As he highlighted, most commercial pet foods are nowhere near these ratios and thus have little value. The most obvious is to the health and appearance of the skin and hair coat. Hair appears thicker, softer and generally healthier. The skin is smoother and much more resistant to injury.
Veterinarians routinely prescribe fatty acid supplementation for dry itchy skin conditions. For years show dogs have been supplemented with omega-3 fatty acids to improve the skin and hair coat. The anti-inflammatory affects of omega-3 fatty acids has been found to be of value in treating osteoarthritis in older pets as well as allergic reactions (Hazewinkel H, Lars FH, et al. The influence of dietary omega-6: omega-3 ratio on lameness in dogs with osteoarthritis of the elbow joint. In Recent Advances in Canine and Feline Nutrition Vol 3) 5.
Recently, omega-3 fatty acids and omega-6 and omega-3 fatty acids in a 5:1 ratio have been found to be of value in treating chronic renal disease. Their vasodilatory properties alter hemodynamics, ower intraglomerular pressure and slow the progression of renal disease in dogs.
What have we learned thus far?
It is all about food. Huumans and pets alike eating food, not individual nutrients as McKibble and McCan is selling you in their formulas. Although the concept of good fats and bad fats has been used in huuman nutrition, dogs and cats are not as susceptible to coronary artery diseases and can therefore consume greater amounts of saturated fats which are considered “bad” fats for huumans 6. It is therefor not advantageous to categorize different types of fats as either “good” or “bad” for our pets in traditional nutritional context, other than highlighting the differences between vegetable oil-based fat versus animal-source based fats. Calling all saturated fats “bad” is an oversimplification of the confusion that reign on this topic at the moment. When they come from dairy and vegetable sources, as well as certain meats, some saturated fats are healthy it seems. The more we get to know about fats, the more equipped we will become to make healthy choices. The key is to understand this discussion is that every specific type of fat has unique effects on the body, and these effects can be good or bad.
Additional Articles and Videos
There are many articles available online for further reading regarding fish, fish oils, krill, and the requirements for Omega’s in your fur kids diets, as well as, of course, fats & oils in general:
- New Study Finds Fat Intake Lowers Mortality Risk, Does Not Increase Heart Disease Risk, The Lancet;
- Recent Advances in Canine and Feline Nutrition, Vol 3, Reinhart GA. Review of Omega-3 fatty acids and dietary influences on tissue concentrations. Wilmington: Orange Frazer press, 1996 235-242 (Amazon)
- Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968-73), The BMJ (British Medical Journal);
- Is Your Dog Missing This Important Fat? By Dana Scott from Dogs Naturally Magazine (Dogs Naturally Magazine);
- From Dr. Mercola – Sardines and Eggs: Natural, Affordable Omega-3 Treats for Your Pet (Mercola);
- Marine Oils and Their Effects, Nutrition Reviews (Oxford Journals) (Adobe Required);
- It’s High in Protein, High in Fat – But Should You Feed It to Your Dog? (Mercola);
- Dogs Naturally Magazine – Balancing Fats for a Healthier Dog (Dogs Naturally Magazine);
- Dogs Naturally Magazine – Fish Oil And Omega-3 For Dogs: Safe Or Not? (Dogs Naturally Magazine);
- Multicenter veterinary practice assessment of the effects of omega-3 fatty acids on osteoarthritis in dogs, Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA., (PubMED);
- The role of dietary omega-3 and omega-6 essential fatty acids in the nutrition of dogs and cats: A review, by Giacomo Biagi, Attilio Mordenti and Massimo Cocchi (University of Bologna) (Research Gate);
- Nutrition and osteoarthritis in dogs: does it help? (PubMED);
- Nutritional management of osteoarthritis. (PubMED);
- The Saturated Fat, Cholesterol, and Statin Controversy: A Commentary
The Journal of the American College of Nutrition;
References and Research
- 1.Ascherio A, Willett WC. Health effects of trans fatty acids. The American Journal of Clinical Nutrition. October 1997:1006S-1010S. doi:10.1093/ajcn/66.4.1006s
- 2.Coate KC, Kraft G, Lautz M, Smith M, Neal DW, Cherrington AD. A High-Fat, High-Fructose Diet Accelerates Nutrient Absorption and Impairs Net Hepatic Glucose Uptake in Response to a Mixed Meal in Partially Pancreatectomized Dogs. The Journal of Nutrition. July 2011:1643-1651. doi:10.3945/jn.111.145359
- 3.Rutherfurd-Markwick KJ, Hendriks WH. Functional foods and nutraceuticals for cats and dogs. Engormix. https://en.engormix.com/pets/articles/functional-foods-nutraceuticals-cats-t33652.htm. Published February 22, 2007.
- 4.VAUGHN DM, REINHART GA, SWAIM SF, et al. Evaluation of Effects of Dietary n-6 to n-3 Fatty Acid Ratios on Leukotriene B Synthesis in Dog Skin and Neutrophils. Vet Dermatol. December 1994:163-173. doi:10.1111/j.1365-3164.1994.tb00028.x
- 5.Anthony E. The Role of Nutrition in Managing Canine Osteoarthritis . VetFolio. https://www.vetfolio.com/learn/article/the-role-of-nutrition-in-managing-canine-osteoarthritis. Published March 8, 2019.