For many years, pet owners have given fatty acids to their dogs and cats to change a dull, dry hair coat into a more glossy one. More recently, veterinarians have found that fatty acids play important roles in other areas of skin and coat health such as allergies, the control of inflammation, joint health, and the function of other body organs in dogs and cats.
What are fatty acids?
Fatty acids are specific types of polyunsaturated fats.
The two main classes of fatty acids we will be discussing are the omega-3’s and the omega-6’s. These classifications are based on molecular characteristics. (For you biochemistry buffs out there, check out the text box at the end of this article.) You may also have heard about omega-9 fatty acids. Omega-9’s actually decrease the concentrations of omega-3 and omega-6 fatty acids in the blood and skin.
Which fatty acids do pets need?
Animals can produce some of the fatty acids they need, but not all of them. Those fatty acids which they can not produce themselves, but must be obtained through their diet, are called ‘essential’ fatty acids. Interestingly, what is ‘essential’ for one species of animal is not necessarily essential for another. For example, the fatty acid, arachidonic acid is essential for cats but not for dogs.
In some disease conditions, certain enzymes which convert one fatty acid to another may be deficient, or the animal may not be able to adequately absorb fatty acids from the intestine. In animals with these conditions, some of the ‘nonessential’ fatty acids actually become ‘essential,’ that is, required in the diet, and in higher amounts. Deficiencies of fatty acids may also occur with the use of fat-restricted diets in overweight dogs.
Fatty acids in foods are subject to degradation. Overcooking can destroy fatty acids. Improper storage or a suboptimal amount of antioxidants in dry food may result in rancidity and a subsequent deficiency in fatty acids.
Omega-3 fatty acids
Omega-3 fatty acids include:
- Alpha-linolenic acid (ALA)
- Eicosapentaenoic acid (EPA)
- Docosahexaenoic acid (DHA)
ALA can be converted into EPA, however, this conversion does not occur in the skin. EPA is the workhorse of the omega-3 fatty acids and is incorporated into the cell membrane.
Omega-6 fatty acids
Omega-6 fatty acids include:
- Linoleic acid (LA)
- Gamma linolenic acid (GLA)
- Dihomo-gamma-linolenic acid (DGLA)
- Arachidonic acid (AA)
LA can be converted into GLA, but not in the skin. However, DGLA can be made from GLA in the skin.
LA is important because it optimizes water permeability in the skin. AA, on the other hand, in increased amounts, is the troublemaker among the fatty acids.
Ratios of fatty acids
Research is being performed to determine the optimal ratio of omega-6 to omega-3 fatty acids that should be consumed. Previously, it was thought that the ratio should be approximately 15:1. Current recommendations are for ratios of 10:1 to 5:1.
Most pet foods contain far more omega-6 fatty acids than omega-3’s. Some pet food companies have added omega-3 fatty acids to their foods to lower the ratio of omega-6 to omega-3 fatty acids. It is important to realize that although the ratios may be a guideline, the actual concentration of EPA in the omega-3’s is what is most important.
Sources of fatty acids
Fat may contain fatty acids, but in extremely varying quantities. For example, beef fat will have a very low percentage of fatty acids, whereas, sunflower oil and fish oil will have much larger percentages.
Fatty acids are found in different quantities in many plants and cold water fish. Marine oils are good sources of EPA and DHA. The other fatty acids are found in higher quantities in certain plants and grains. Sunflower oil and safflower oil are especially high in LA.
As mentioned previously, most pet foods contain far more omega-6 than omega-3 fatty acids. It has been found that cattle and poultry fed increased omega-3 fatty acids will produce meat and eggs higher in omega-3 fatty acids. In the future, the use of these products in pet food may help to optimize the omega-6 to omega-3 ratio in the diet.
How fatty acids function in inflammation
|EPA, DHA, and DGLA decrease the harmful effects of AA.|
Both AA and EPA can be incorporated into cell membranes. When a cell is damaged, AA is released from the cell membrane and ismetabolized by enzymes into substances which increase inflammation and pruritus (itching). EPA is also released when a cell is damaged. It competes with AA for the same metabolic enzymes. EPA results in the production of less inflammatory substances. DHA also results in the production of less inflammatory substances. So DHA and EPA decrease the harmful effects of AA.
DGLA also competes with AA for enzymes. In addition, DGLA causes the release ofprostaglandin E1 (PGE), a substance which inhibits the release of AA from the cell membrane.
Indications for the use of supplemental fatty acids
From that complicated description, we hope you can see that by supplementing with EPA, DHA, and GLA (which the body can easily convert to DGLA) we may be able to lessen the effects of inflammation. Fatty acids affect a number of body systems and conditions, as described below.
Allergies and Autoimmune Conditions: Allergies and autoimmune conditions occur because the immune system over-reacts. Certain fatty acids can lessen the harmful effects these diseases can have on the body.
Arthritis: Research is showing that omega-3 fatty acids, especially EPA, may be helpful in reducing the inflammation associated with arthritis.
Other Inflammatory Diseases: Other diseases which are accompanied by inflammation such as ulcerative colitis, inflammatory bowel disease, and rheumatoid arthritis may respond to the anti-inflammatory effects of certain fatty acids.
Dull and Dry Hair Coats: Haircoats which are dull, brittle, and dry often respond to supplementation with essential fatty acids, especially LA. It has also been found that in some cases of seborrhea, there is a deficiency of LA in the skin. In these cases, supplements high in LA are useful. The addition of EPA and GLA is also beneficial in that it would help negate the release of AA from cells damaged because of this skin condition.
Yeast Infections: Fatty acids have been shown to slow down the growth of Malassezia pachydermatis, a common yeast infection in dogs and cats, in the laboratory. It is thought, these fatty acids may play a beneficial role in the treatment of this yeast infection on the skin and ears in dogs and cats.
Preventing Atopy: Some researchers have suggested that fatty acid supplements may be useful to prevent atopy (allergies to inhaled substances such as pollens and molds) from developing in young animals. The theory is that pregnant atopic mothers have a decreased amount of PGE in their systems. PGE is necessary for the development of a healthy immune system in neonates. If the mothers are deficient in PGE, their offspring may be more likely to develop abnormal immune systems which would make them more prone to atopy themselves. Since GLA, when converted to DGLA, causes the release of PGE, giving GLA to a pregnant female in the last month of pregnancy and during lactation may increase PGE and decrease the incidence of the offspring developing atopy.
Eyes: In addition to their effects on the developing immune system, omega-3 fatty acids are also essential for the proper development of the retina and visual cortex.
Heart Problems: Evidence suggests, omega-3 fatty acids may prevent certain cardiac problems as well. Ventricular arrhythmias in dogs have been prevented and high blood pressure has been reduced in dogs supplemented with fatty acids. Animals prone to thromboembolisms may be helped by the anti-clotting effect fatty acids have on platelets.
Cancers: Omega-3 fatty acids have been shown to slow the development and metastasis of certain cancers. Omega-6 fatty acids, on the other hand, have been shown to stimulate tumor development.
Plasma Triglycerides and Cholesterol: Fish oils have been shown to decrease levels of triglycerides and cholesterol in the blood. Animals receiving retinoid therapy (synthetic vitamin A derivatives) for various skin problems may develop hyperlipidemia. Fish oils may benefit these patients.
It should be obvious that fatty acids are necessary for the normal function of many systems of the body. It is also obvious that not all fatty acids are equal. Because the different fatty acids have different effects, the choice of a fatty acid supplement needs to be based on the specific condition we are trying to manage.
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