Autoimmune Diseases in Pets

Autoimmune diseases, which occur more commonly in dogs than in cats, are those diseases in which the pet’s body forms antibodies attacking its own tissues. The exact cause of autoimmune diseases is not known. However, many doctors feel that the immune system may malfunction as a result of infections or chronic exposure to toxins. The fact an increased number of cases are seen shortly following repeated immunization prompts many holistic doctors to surmise vaccinations may be responsible for the formation of autoimmune disease in some pets.

Commonly diagnosed autoimmune diseases include:

• Autoimmune Hemolytic Anemia (AIHA). In this disorder, the pet forms antibodies against its own red blood cells, causing anemia.
• Hypothyroidism. The pet forms antibodies against its thyroid gland.
• Immune-Mediated Thrombocytopenia (ITP). In this disorder, the pet forms antibodies against its own platelets, causing reduced blood-clotting ability.
• Keratoconjunctivitis Sicca (KCS). Also called “dry eye,” dogs with this disorder form antibodies against their tear glands, causing chronic eye disease.
• Pemphigus. A number of disorders make up the pemphigus complex of diseases. In these disorders, the pet forms antibodies against its skin.
• Rheumatoid Arthritis (RA). In this disorder, the pet forms antibodies against its own joint tissues, causing lameness and arthritis.
• Systemic Lupus Erythematosus (SLE). Also called lupus, in this disorder, the pet forms antibodies against a number of its tissues, including blood cells, skin, and the kidneys.

PRINCIPAL NATURAL TREATMENTS ANTIOXIDANTS
Certain vitamins and minerals function in the body to reduce oxidation. Oxidation is a chemical process that occurs within the body’s cells. After oxidation occurs, certain by-products such as peroxides and “free radicals” accumulate. These cellular by-products are toxic to the cells and surrounding tissue. The body removes these by-products by producing additional chemicals called antioxidants that combat these oxidizing chemicals.

In disease, excess oxidation can occur and the body’s normal antioxidant abilities are overwhelmed. This is where supplying antioxidants can help. By giving your pet’s body extra antioxidants, it may be possible to neutralize the harmful by-products of cellular oxidation.

Several antioxidants can be used to supplement pets. Most commonly, the antioxidant vitamins A, C and E, and the minerals selenium, manganese, and zinc, are prescribed. Other antioxidants, including N-acetylcysteine, Coenzyme Q10, Ginkgo biloba, bilberry, grape seed extract, and pycnogenol may also be helpful for a number of disorders. There is no “correct” antioxidant to use. Dosage varies with the specific antioxidant chosen.

Following is a brief discussion of a commonly used group of antioxidants called bioflavonoids/proantyocyanidins.

PROANTAHOCYANIDINS
Proanthocyanidins (also called pycnogenols or bioflavonoids, a class of water-soluble plant-coloring agents; while they don’t seem to be essential to life, it’s likely people and pets need them for optimal health) are naturally occurring polyphenolic compounds found in plants. Most often, products containing proanthocyanidins are made from grape seeds or pine bark. These compounds are used for their antioxidant effects against lipid (fat) peroxidation. Proanthocyanidins also inhibit the enzyme cyclooxygenase (the same enzyme inhibited by aspirin and other nonsteroidal medications); cyclooxygenase converts arachidonic acid into chemicals (leukotrienes and prostaglandins), which contribute to inflammation and allergic reactions. Proanthocyanidins also decrease histamine release from cells by inhibiting several enzymes.

Some research suggests that pycnogenol seems to work by enhancing the effects of another antioxidant, vitamin C. Other research suggests the bioflavonoids can work independently of other antioxidants; as is the case with many supplements, there probably is an additive effect when multiple antioxidants are combined. People taking pycnogenol often report feeling better and having more energy; this “side effect” may possibly occur in our pets as well.

Quercetin is a natural antioxidant bioflavonoid found in red wine, grapefruit, onions, apples, black tea, and in lesser amounts, in leafy green vegetables and beans. Quercetin protects cells in the body from damage by free radicals and stabilizes collagen in blood vessels.

Quercetin supplements are available in pill and tablet form. One problem with them, however, is they don’t seem to be well absorbed by the body. A special form called quercetin chalcone appears to be better absorbed.

Quercetin appears to be quite safe. Maximum safe dosages for young children, women who are pregnant or nursing, or those with serious liver or kidney disease have not been established; similar precautions are probably warranted in pets.

In people, a typical dosage of proanthocyanidins is 200 to 400 mg three times daily. Quercetin may be better absorbed if taken on an empty stomach. The suggested dosage of proanthocyanidin complex in pets is 10 to 20 mg give daily (divided into two or three doses). The suggested dosage of bioflavonoid complex in pets is 200 to 1,500 mg per day (divided into two to three doses). The actual dosage of each product will vary with the product and the pet’s weight and disease condition.

While there is no specific research showing benefit in specific autoimmune disorders, the use of antioxidants is widely recommended by holistic veterinarians to reduce oxidative damage to tissues that may occur in various autoimmune disorders. More research on antioxidants and other complementary therapies in the treatment of autoimmune disorders is needed.

OMEGA-3 FATTY ACIDS
Omega-3 fatty acids — eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) — are derived from fish oils of cold water fish (salmon, trout, or most commonly menhaden fish) and flaxseed. Omega-6 fatty acids — linoleic acid (LA) and gamma-linolenic acid (GLA) — are derived from oils of seeds such as evening primrose, black currant, and borage. Often, fatty acids are added to the diet with other supplements to attain an additive effect.

Just how do the fatty acids work to help in controlling inflammation in pets? Cell membranes contain phospholipids. When membrane injury occurs, an enzyme acts on the phospholipids in the cell membranes to produce fatty acids including arachidonic acid (an omega-6 fatty acid) and eicosapentaenoic acid (an omega-3 fatty acid). Further metabolism of the arachidonic acid and eicosapentaenoic acid by additional enzymes (the lipooxygenase and cyclooxgenase pathways) yields the production of chemicals called eicosanoids. The eicosanoids produced by metabolism of arachidonic acid are pro-inflammatory and cause inflammation, suppress the immune system, and cause platelets to aggregate and clot; the eicosanoids produced by metabolism of eicosapentaenoic acid are non-inflammatory, not immunosuppressive, and help inhibit platelets from clotting. (There is some overlap and the actual biochemical pathway is a bit more complicated than I have suggested here. For example, one of the by-products of omega-6 fatty acid metabolism is Prostaglandin E1, which is anti-inflammatory. This is one reason why some research has shown that using certain omega-6 fatty acids can also act to limit inflammation.)

Supplementation of the diet with omega-3 fatty acids works in this biochemical reaction. By providing extra amounts of these non-inflammatory compounds, we try to overwhelm the body with the production of non-inflammatory elosanoids. Therefore, since the same enzymes metabolize both omega-3 and omega-6 fatty acids, and since metabolism of the omega-6 fatty acid tends to cause inflammation (with the exception of Prostaglandin E1 by metabolism of omega-6 as mentioned), by supplying a large amount of omega-3 fatty acids we favor the production of non-inflammatory chemicals.

Many disorders are due to overproduction of the eicosanoids responsible for producing inflammation. Fatty acid supplementation can be beneficial in inflammatory disorders by regulating the eicosanoid production. While not proven, many holistic veterinarians recommend anti-inflammatory agents such as omega-3 fatty acids in an attempt to regulate the immune response in pets with autoimmune disorders. While controlled studies are lacking, may doctors feel there is some benefit to their use.

In general, the products of omega-3 (specifically EPA) and one omega-6 fatty acid (DGLA) are less inflammatory than the products of arachidonic acid (another omega-6 fatty acid). By changing dietary fatty acid consumption, we can change eicosanoid production right at the cellular level and try to modify (decrease) inflammation within the body. By providing the proper (anti-inflammatory) fatty acids, we can use fatty acids as an anti-inflammatory substance. However, since the products of omega-6 fatty acid metabolism (specifically arachidonic acid) are not the sole cause of the inflammation, fatty acid therapy is rarely effective as the sole therapy but is used as an adjunct therapy to achieve and additive effect.

While many doctors use fatty acids for a variety of medical problems, there is considerable debate about the use of fatty acids. The debate concerns several areas:

DOSAGES
What is the “best” dose to use in the treatment of pets? Most doctors use anywhere from two to ten times the label dose. Research in the treatment of allergies indicates the label dose is ineffective; the same theory probably holds true for treating autoimmune disorders, but the research is lacking. In people, the dosage that showed effectiveness in many studies was 1.4 to 2.8 gm of GLA per day, or 1.7 gm of EPS and 0.9 gm of DHA per day, which is hard for people to obtain from the supplements currently available. If this were shown to be the correct dosage for pets, a 50-pound dog would need to take ten or more fatty acids capsules per day to obtain a similar dosage, depending upon which supplement (and there are many choices on the market) was used. Therefore, while the studies with omega-3 fatty acids show many potential health benefits, it is almost impossible to administer the large number of capsules needed to approximate the same dosage used in these studies. The best that owners can hope for at this time is to work with their veterinarians and try to increase, as best as possible, the amount of omega-3 fatty acids in the diet.

WHICH FATTY ACID?
What is the “correct fatty acid to use? Should we use just omega- 3 (EPA and DHA) fatty acids, or combine them with omega- 6 (GLA) fatty acids? Is there an “ideal” ratio of omega-6 to omega-3 fatty acids? Through research on pets with atopic dermatitis, the ideal dietary ratio seems to be 5:1 of omega- 6:omega-3 fatty acids, although this is also debated. Whether or not this “ideal” dietary ratio is ideal for the treatment of autoimmune disorder and other inflammatory conditions remains to be seen.

FATTY ACID SUPPLEMENTATION
Is supplementation with fatty acid capsules or liquids the best approach, or is dietary manipulation preferred for the treatment of inflammatory conditions? There are, in fact, diets constructed with this “ideal” ratio (of omega-6 to omega-3 fatty acids). For owners who do not like giving their pets medication, or for those pets who don’t take the fatty acid supplements easily, it might be wise to try some of these medically formulated diets (available from your pet’s doctor) that contain the fatty acids. (However, because these medicated diets may not be as natural as possible due to the inclusion of byproducts and chemical preservatives, holistic pet owners may need to try other options.) These diets, often prescribed as anti-inflammatory diets for pets with allergies, may be useful as a part of the therapy of autoimmune disorders in pets.

FISH OILS
Since fish oils can easily oxidize and become rancid, some manufacturers add vitamin E to fish oil capsules and liquid products to keep the oil from spoiling (others remove oxygen from the capsule).

Since processed foods have increased omega-6 fatty acids and decreased omega-3 fatty acids, supplementing the diets of all pets with omega-3 fatty acids seems warranted and will not harm your pet.

The bottom line is there are many questions regarding the use of fatty acid therapy. More research is needed to determine the effectiveness of the fatty acids in the treatment of various medical problems, as well as the proper doses needed to achieve clinical results. Until definitive answers are obtained, you will need to work with your doctor (knowing the limitations of current research) to determine the use of these supplements for your pet.

Fish oil appears to be safe. The most common side effect seen in people and pets is a fish odor to the breath or the skin. Because fish oil has a mild “blood-thinning” effect, it should not be combined with powerful blood-thinning medications, such as Coumadin (warfarin) or heparin, except on a veterinarian’s advice. Fish oil does not seem to cause bleeding problems when it is taken by itself at commonly recommenced dosages. Also, fish oil does not appear to raise blood sugar levels in people or pets with diabetes.

FLAXSEED OIL
Flaxseed oil is derived from the seeds of the flax plant and has been proposed as a less smelly alternative to fish oil. Flaxseed oil contains alpha-linolenic acid (ALA), an omega-3 fatty acid that is ultimately converted to EPA and DHA. In fact, flaxseed oil contains higher levels of omega-3 fatty acids (ALA) than fish oil. It also contains omega-6 fatty acids.

As mentioned, many species of pets (probably including dogs and cats) and some people cannot convert ALA to these other more active non-inflammatory omega-3 fatty acids. In one study in people, flaxseed oil was ineffective in reducing symptoms or raising levels of EPA and DHA. While flaxseed oil has been suggested as a substitute for fish oil, there is no evidence it is effective when used for the same therapeutic purposes as fish oil. Unlike the case for fish oil, there is little evidence flaxseed oil is effective for any specific therapeutic purpose.

Therefore, supplementation with EPA and DHA is important, and this is the reason flaxseed oil is not recommended as the sole fatty acid supplement for pets. Flaxseed oil can be used to provide ALA and as a coat conditioner.

Flaxseed oil also does contain lignans, which are currently being studied for use in preventing cancer in people.

The essential fatty acids in flax can be damaged by exposure to heat, light, and oxygen (essentially, they become rancid). For this reason, you shouldn’t cook with flaxseed oil. A good product should be sold in an opaque container, and the manufacturing process should keep the temperature under 100 degrees F (some products are prepared by cold extraction methods). Some manufacturers combine the product with vitamin E because it helps prevent rancidity.

The best use of flaxseed oil is as a general nutritional supplement to provide essential fatty acids.

Flaxseed oil appears to be a safe nutritional supplement when used as recommended.

These supplements can be used in conjunction with conventional therapies as they are unlikely to be effective by themselves in most patients. The natural treatments are widely used with variable success but have not all been thoroughly investigated and proven at this time.

As with any condition, the most healthful natural diet will improve the pet’s overall health.

OTHER NATURAL TREATMENTS
Other therapies that can be tried include the herbs alfalfa, yellow dock, and cordyceps mushrooms.

CONVENTIONAL THERAPY
Specific therapies vary with the disease. In general, conventional therapies rely on immunosuppressive medications such as corticosteroids or stronger chemotherapeutic drugs to decrease overactive immune system.