ASTHMA ASTHMAPrincipal Natural Treatments
Omega-3 fatty acids, orthomolecular therapy
Other Natural Treatments
Natural diet, antioxidants, herbs: boswellia, cat’s claw, coltsfoot, ephedra, feverfew, garlic, German chamomile, Ginkgo biloba, licorice, lobelia, turmeric
Asthma (feline bronchial disease) is an inflammatory disease affecting the smooth muscle of the bronchi of cats (and rarely dogs). The inflammation causes reversible airflow obstruction through smooth muscle constriction, bronchial wall fluid buildup (edema), and thickening of the mucous glands of the airways. This inflammation, occurring as a result of a reaction (allergy) to environmental allergens (foreign proteins), causes coughing and/or wheezing. Secondary infection (pneumonia) is reported to occur in 24 to 42% of cats with asthma. Because feline heartworm disease can cause signs that mimic asthma, all cats with respiratory signs should be screened for feline heartworm disease. As much as possible, owners should try to minimize environmental factors (such as cigarette smoke, dust, hair spray, and perfume) that can trigger an asthmatic attack.
The main natural treatments are designed to reduce wheezing and inflammation in pets with asthma.
Omega-3 fatty acids—eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)—are derived from fish oils of coldwater 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 the 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 cyclooxygenase 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 eicosanoids. Therefore, since the same enzymes metabolize both omega-3 and omega-6 fatty acids, and since metabolism of the omega-6 fatty acids 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, including asthma, 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.
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 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 an additive effect.
Note: Flaxseed oil is a popular source of alpha-linoleic acid (ALA), an omega-3 fatty acid that is ultimately converted to EPA and DHA. However, many species of pets (probably including dogs) 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 less smelly substitute for fish oil, there is no evidence that it is effective when used for the same therapeutic purposes as fish oil. 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.
Omega-3 fatty acids have been recommended for the treatment of asthma in pets as this is often a result of inflammation in the airways. While controlled studies are lacking, many doctors feel there is some benefit to their use.
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:
What is the “best” dose to use in the treatment of pets? Most doctors use anywhere from 2 to 10 times the label dose. Research in the treatment of allergies indicates that the label dose is ineffective; the same theory probably holds true for treating asthma, 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 EPA 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 10 or more fatty acid 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.
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 asthma and other inflammatory conditions remains to be seen.
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 by-products 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 asthmatic 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 that 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 doctors (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 recommended 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 that it is effective when used for the same therapeutic purposes as fish oil. Unlike the case for fish oil, there is little evidence that 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° 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.
Orthomolecular medicine (often called “megavitamin therapy”) seeks to use increased levels of vitamins and minerals (mainly antioxidants) to help treat a variety of medical disorders. While daily amounts of vitamins and minerals have been recommended as an attempt to prevent nutritional deficiencies, orthomolecular medicine uses higher doses as part of the therapy for disease.
The pet food industry relies on recommendations by the National Research Council (NRC) to prevent diseases caused by nutrient deficiencies in the “average” pet, yet the NRC has not attempted to determine the optimum amount of nutrients or their effects in treating medical disorders. While a minimum amount of nutrients may be satisfactory in preventing diseases caused by nutrient deficiencies, it is important to realize that there is no “average” pet, and that every pet has unique nutritional needs.
It is unlikely that our current recommendations are adequate to maintain health in every pet. Each pet has unique requirements for nutrients. Additionally, these needs will vary depending upon the pet’s health. For example, in times of stress or disease, additional nutrients above and beyond those needed for health will be required. Orthomolecular medicine evaluates the needs of the pet and uses increased nutrients to fight disease.
Note: Owners should not diagnose and treat their pets without veterinary supervision. Many medical disorders present similar symptoms. Also, megavitamin therapy can be toxic if not used properly.
The orthomolecular approach to treating asthma uses a hypoallergenic, healthful diet as the starting point. This diet should be free of chemicals, impurities, and by-products. A blood profile is done to rule out endocrine diseases such as Cushing’s disease and hypothyroidism, as antioxidants may create changes in blood values that are normally used to screen for these common disorders.
Treatment requires borrowing from treatments recommended for other allergic or inflammatory conditions and uses vitamin A (10,000 IU for small dogs and cats, up to 30,000 IU for large dogs), crystalline ascorbic acid (750 mg for small dogs and cats, up to 3,000 mg for large dogs), and vitamin E (800 IU for small dogs and cats, up to 2,400 IU for large dogs). The antioxidant mineral selenium (20 meg for small dogs and cats, up to 60 meg for large dogs) is also added to the regimen. Once asymptomatic, a maintenance protocol using lower dosages of vitamins A and E and the mineral selenium is prescribed to reduce the chance for toxicity.
Other complementary therapies for pets with asthma include natural diet and the following herbs: boswellia, cat’s claw, coltsfoot, ephedra, feverfew, garlic, German chamomile, Ginkgo biloba, licorice, lobelia, and turmeric.
Often asthmatic pets still require conventional medications. The supplements can be used in conjunction with conventional therapies as they are often ineffective by themselves in most patients with severe asthma. 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.
Conventional therapy for dogs and cats with asthma includes the use of corticosteroids and bronchodilators.
Corticosteroids can be given by injection, by mouth, or by both routes of administration. The most commonly used corticosteroids are prednisone, prednisolone, dexamethasone, and triamcinolone. Corticosteroid injections can be short-acting or longer-acting (depot) injections.
While very effective when used to control inflammation and decrease airway sensitivity, corticosteroids have both short-term as well as long-term side effects. Short-term side effects include increased water intake, increased urination, increased appetite, destruction of joint cartilage, and very rarely, either depression or excitability. Long-term side effects that can occur are numerous and include suppression of the immune system, infections, diabetes, liver disease, osteoporosis, Cushing’s disease, and obesity. Side effects, both short- and long-term, are common in dogs but relatively rare in cats.
When needed, short-term use of fast-acting corticosteroids are preferred. Depot injections, while commonly used in cats, should rarely, if ever, be used in dogs. In cats, an occasional depot injection (1 to 3 times per year) is usually not associated with side effects, but when possible, short-acting injections and oral corticosteroids are preferred.
Bronchodilators commonly used to treat arthritis in pets include aminophylline and theophylline. These medications are methylxanthine derivatives that act as respiratory smooth muscle relaxing agents. Biochemically, they work by competing with the enzyme phosphodiesterase, which increases the levels of cyclic AMP, resulting in the release of epinephrine. Increased levels of cyclic AMP may also inhibit two chemicals produced in the body, which contribute to signs seen in asthmatic patients: histamine, and the slow-reacting substance of anaphylaxis (SRS-A). In addition to relaxing respiratory smooth muscles, they also relax the smooth muscles of the blood vessels of the respiratory tract and remove excess fluid from the body via their diuretic actions.
Aminophylline and theophylline should be used cautiously in pets with heart disease, stomach ulcers, hyperthyroidism, kidney disease, liver disease, and high blood pressure. Older pets may be more sensitive to side effects. Preexisting heart arrhythmias may worsen in pets receiving aminophylline or theophylline. Additional side effects include central nervous system stimulation and gastrointestinal stimulation. These medications have a narrow therapeutic index, which means there is a very small difference between the effective dose and the toxic dose.