Fats and Oils in the Diet?
Certain fats, called essential fatty acids (EFA) (also commonly known as omega 3 and 6 oils) cannot be made by the animal and therefore must be obtained from food. These essential 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 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 both people and pets, every person and animal needs some cholesterol. Cholesterol is important because important hormones (testosterone, progesterone, estrogen) are made from cholesterol.
While fats are essential and many can be beneficial, others can be harmful and too much of any fat can lead to obesity and the host of health problems that often come with it, as we stated above. Many commercial pet food manufacturers add large amounts of low grade, highly processed fats (usually just referred to as 'oils and fats' or 'animal fats') to make the food more palatable. Unfortunately, these fats tend to contain large amounts of saturated and hydrogenated fats which can raise blood cholesterol and may contribute to heart disease.
- 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.
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 fibre, 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 pets, however. 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 introduced abruptly also may cause problems. Undigested fat causes steatorrhea. 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 dietary fat increases.
Excess 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 at a 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 recommended at all). 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, 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 commercial pet foods. 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 diarrhoea. Therefore, most diets recommended for the management of chronic diarrhoea are low in fat, even for dogs and cats with no loss in their ability to digest and absorb fats. In a recent study (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, details below) 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 [ref], hyperglycemia [ref], 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 commercial grain-based pet foods. 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.
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.
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. 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" that is still relevant today.
In the article, he indicated 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: Wilmington: Orange Frazer press, 1996 235-242.].
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: Wilmington: Orange Frazer press, 1996 235-242. ((The Iams Company, Lewisburg, OH.)].
In order for there to be maximum benefit from these fatty acids they must be in a proper ratio to one another [Vaughn DM, Reinhart GA, et al Evaluation of dietary n-6 to n-3 fatty acid ratios on leukotriene B synthesis in dog skin and neutrophils. Veterinary Dermatology 1994; 5(4):163-173. [ref]].
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. 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: Wilmington: Orange Frazer Press, 1998 vol.2; 325-336. and The Role of Nutrition in Managing Canine Osteoarthritis, by Elaine Anthony,MA,CVT, Veterinary Technician, January 2005 (Vol 26,No 1) (VetFolio)].
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, lower intraglomerular pressure and slow the progression of renal disease in dogs.
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:
- 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)