Body

VetInfo Digest September 2004

Table of Contents:
Definitions for Nutraceuticals, OTC Medications and Herbal Therapies
Basic Thoughts on these Medications.
Use for:
Skin
Heart
Liver
Kidney

This Month's Note:
I have been answering questions related to veterinary medicine online now for ten years. During all but one year of that time I have also been a full time practicing veterinarian in a rural veterinary practice in Virginia. I really enjoy practicing veterinary medicine but I don't get to pursue difficult cases as often as I would like.
There are many times when clients simply refuse to allow us to pursue really good quality care due to monetary concerns, fear of injuring or losing a pet and sometimes simply because they can't bring themselves to make a decision that might harm their pet, even though most people would agree that the risk is justified to obtain the benefits for their pet's medical problem. When this happens it is helpful to think about the subscribers to our web site, who have taken the time to look for information on their pet's medical condition and are usually seeking the best way to care for the problem.
Hopefully as time goes on, more and more people will come to value their pets and to take responsibility for them in the way that you do. Until then, it is a welcome relief some days to sit down and help people figure out what the best plan to deal with a problem rather than a compromise that increases the risk and lowers the possible rewards in many cases.

Definitions and Basic Information
Last month I started a list of the common OTC medications that we use in practice. This month I am going to expand on that list by going over some of the herbs, "nutraceuticals" and other available medications that are being used to treat medical problems in pets.
It might be helpful to start off with some definitions and brief descriptions.
Over-the-Counter or OTC medications are available without a prescription. They are generally recognized as being safe for consumers to use if they follow the label directions. Medications that are OTC for humans are not necessarily safe for pets, though. In some cases OTC medications made for humans can have severe effects when used to medicate pets. An example of this is acetaminophen (Tylenol Rx), which is very toxic for cats. Some of the OTC medications that are labeled for pets got their approval years and years ago and are either not as effective as newer medications or have toxic effects that wouldn't be tolerated under newer guidelines. Examples of these medications include toulene, which can be found in some OTC deworming capsules. It is not very likely that toulene could gain approval today when compared with newer safer medications. Some OTC medications are new medications or new formulas marketed under an old familiar name. Kao-Pectate (tm) recently changed its formula back to an older formula which contains salicylates. (Please note that last month I mentioned this and inadvertently said Pepto-Bismal (tm) instead of KaoPectate). While this is no problem for dogs it is conceivable that a cat could be harmed by the use of Kao-Pectate in the formula that contains salicylates. Whenever you think about using an OTC medication it is best to check with your veterinarian or another reliable information source before giving it to your pet.
Nutraceuticals are a name for a group of products that claim medical benefits but do not fit cleanly into established food groups and have not been examined by the FDA as medications. This is a group of food or medical supplements that are not regulated as tightly as either foods or medications by the FDA. The ambiguity of whether these supplements are foods or medications makes regulation of them uncertain. Despite this, there are several supplements that fall into the class of agents generally recognized as nutraceuticals that do seem to have beneficial effects in at least a few patients. Perhaps the oldest of the nutraceuticals is brewer's yeast. For years there have been claims that brewer's yeast would either prevent flea infestation or kill fleas, despite several studies that refute this claim convincingly. Newer nutraceuticals have come along that do seem to be effective for other conditions, at least in some dogs and cats. There is an effort underway at the Food and Drug Administration (FDA) to gain some control over the nutraceutical industry but so far this is still a largely unregulated group of substances.
Nutrients or vitamins can be used to treat some conditions. For a long time it has been clear that variations from normal diets can help to relieve the symptoms of kidney failure, help control blood sugar in diabetics and provide many other benefits. Supplementation of vitamins above the minimum requirements for life has been advocated for the medical treatment of some conditions. Vitamin E is reported to be helpful in patients with some immune mediated diseases, for instance. An industry has sprung up around the need for specialized diets for pets. An early manufacturer of diets with special claims for medical benefit was Hill's Prescription Diet (tm) line. The name is misleading, as the FDA and other regulating bodies do not recognize the prescription status of foods. However, this is also an area of limbo when it comes to oversight. The FDA seems to be content to allow the sale of these products to be restricted to use under the advice of a veterinarian based on company sales policy. In addition there has been an advisory letter sent to veterinarians (at least in Virginia) stating that even though prescription diets aren't truly prescription by regulation there is some regulatory oversight and if veterinarians do not honor the policies of restricting sale of these products to pets who they have a valid client/patient relationship with they may be jeopardizing future availability of "prescription type" diets.
Herbs are plants , in this case presumably ones with medicinal value. The use of herbs should not be confused with homeopathy, which is a different concept than treating patients with herbs that are thought to have a beneficial effect. In the United States herbs are pretty much unregulated, unless they have been shown to be harmful or claims are made about their effectiveness for the treatment of serious illnesses. Herbs sometimes contain large quantities of substances that can produce effects on the way a body functions. They should be considered to be medications in plant form, rather than alternatives to medications.
There are several philosophies concerning the use of herbal medications. At the present time a popular one is often referred to as "traditional Chinese medicine" (TCM), at least in the U.S. Practitioners of TCM seem to believe that it is not possible to separate the traditional way of explaining illness and of deciding which herbs to use from the use of the herbs themselves. Therefore, practitioners who believe in the use of the traditional Chinese herbal remedies may have adopted a practice philosophy based largely on faith in the observational powers of Chinese healers over many generations, rather than basing their claims on evidence collected in a scientific manner. This doesn't necessarily mean that there isn't value to the TCM method of practice but it should make users a little cautious. After all, traditional European medicine included the use of mercury and other substances now known to be toxic for hundreds of years before the risk of long term toxicity was proven. There is substantial evidence that at least a few of the TCM combination herbal remedies have toxic effects on the liver or other organs.
Homeopathy is the use of extremely dilute substances that are supposed to stimulate the body's immune system or other body systems to learn to control symptoms associated with various diseases. The dilution factors for many homeopathic medications make it likely that they contain none of the original ingredients or that the ingredients are present at concentrations of less than 1 part per billion. I do not believe that true homeopathic medications could conceivably be effective and I do not intend to discuss them in this issue. Be aware that the term "homeopathic" seems to be applied to a number of medications which are not made in the true homeopathic method and these medications should be considered much more carefully as they may actually contain active ingredients.
Aromatherapy is the use of aromatic oils to try to gain benefit from them. There isn't enough real research on aromatherapy to draw any conclusions about benefits or risks that might be associated with its use. Over time this situation may change but right now the use of aromatherapy is definitely a "use at your own risk" situation.

Basic Considerations When Considering Use of Alternative, OTC and Nutraceutical Medications:
When discussing over-the-counter, herbal, nutraceutical and similar therapies it is necessary to think a little bit about what the standards of use should be. In many instances these substances are used for treating, or attempting to prevent, chronic illnesses for which:
1) prescription medications are not available
2) prescription medications are effective and available but are very costly
3) prescription medications are effective but not enough to produce a great quality of life or are available but of questionable effectiveness.
4) prescription medications are effective but have undesirable side effects
In a situation in which there is a prescription pharmaceutical that is known to be highly effective, is known to be very safe and is also reasonably priced, there is little pressure or desire to find alternative medications.
With these things in mind, then, what is the average person looking for in a nonprescription medication or substance with reported health benefits?
The minimum standard should probably be that the substance is safe to use. Unfortunately, even this standard can not be assumed simply because a medication or other substance is available without a prescription. If a product is safe but its effectiveness is questionable but there is no better alternative it is hard to argue against its use as long as the cost does not limit the availability of funds for other necessary care. There are a large number of products available to pet owners that fall into this category of generally being thought to be safe but where no real substantial proof of effectiveness exists.
A more moderate standard would be safe to use with at least some evidence for effectiveness or possibly some safety concerns but good evidence of effectiveness.
A hard line stance on the use of food supplements, OTC medications, herbs, etc. would be to insist that there be proof of safety and proof of effectiveness for all substances, whether they are prescription medications or substances that are not controlled by prescription.
From a personal standpoint, I try to look at each pet's needs and each client's need to seek alternative medications differently. I might encourage a client who seems to need to do something, even it isn't necessary, to use a safe product even if I wasn't sure of its effectiveness. On the other hand, when I am treating a chronically ill pet with several medications I tend to want to be sure that all additional medications or food supplements be both safe and effective because the more things that are being given to a pet, the more likely that two of them will interact in some way that isn't good for my patient. A client who is very wealthy and can afford to pursue all avenues of care might be able to handle giving a pet several food supplements that add to the cost of therapy with no problem. A client who is just barely getting by needs to use the most effective medications they can afford and avoid using medications that add to the cost and don't add to the effectiveness of treatment.
I'm going to try to cover commonly recommended alternatives to prescription medications, or additional avenues of therapy that can be pursued based on the body systems being treated in the rest of this month's VetInfo Digest. I'll try to point out which ones have been tested in pets or the general theories that result in recommendations to use certain groups of medications.

Skin
The skin is one of the more complex organs of the body. It has a very diverse job. It is subject to all sorts of chronic conditions that often respond only partially to therapy. Therefore, it is a favorite of people who want to market products that enhance or replace pharmaceuticals.
Inflammatory disorders are a constant problem with skin. The normal reaction to foreign invaders, injuries, allergies and most other things that affect the skin is inflammation. The results of therapy directed towards the skin are often fairly obvious but for some reason this doesn't limit the placebo effect much at all in dermatology. In chronic conditions, especially ones that tend to wax and wane some on their own, judging partial effectiveness associated with medications is extremely difficult -- and it is even more difficult when the patients can't talk. It takes a great deal of objectivity to evaluate the effect of substances used to treat skin disease without being swayed by day to day variations in the disease process.
There is pretty good evidence at this time that n-3 polyunsaturated fatty acid (n3 PUFA) supplementation can be beneficial for dogs and cats with inflammatory skin diseases, including allergies, immune mediated diseases and even disorders that occur for reasons that are not yet fully understood. Marine fish oils are a good source of the n3PUFAs. The dosages recommended for anti-inflammatory effects are usually calculated on the eicosapentaenoic acid (EPA) content of the fish oil and generally fall close to the 60mg/kg range. This is almost always more than the recommended dosage on the label of the product.
Antioxidants may be beneficial in the treatment of chronic skin disease. The most commonly recommended antioxidant for skin disease is probably Vitamin E. The recommended dose range is generally 200 to 800 IU/day, depending on the size of the pet.
Antihistamines can be useful for skin disease. In dogs the two antihistamines that have been shown to be beneficial most often in studies are diphenhydramine (Benedryl Rx) dosed at 1mg/kg and clemastine (Tavist Rx) dosed at 1.34mg/30 to 60 lbs. of body weight. In cats chlorpheniramine (Chlortrimeton Rx) dosed at 2mg every 12 hours seems to be beneficial.
Hydrocortisone creams (1% hydrocortisone, Cort-Aid (tm), Lanacort (tm), many others) can be useful for the treatment of allergic ear inflammation and inflammatory skin disorders. While the OTC hydrocortisone creams are not extremely effective the early use of these products to control skin inflammation associated with allergies can be very helpful in limiting the severity of the skin disease that occurs.
Oatmeal shampoos and oatmeal rinses can be soothing when a pet has generalized skin disease. There are a number of shampoos made to treat various skin disorders that are available. Your vet is probably the best guide to which of these may be helpful for your dog -- or cat, if bathing is an option. These are OTC products in most cases even when sold through veterinarians.
When skin around the rectum is irritated by diarrhea it can be helpful to use ointments made for diaper rash, such as Desitin (tm) or A&D ointments. Drying moist skin with baby powders or things like Gold Bond (tm) powder can be very helpful in preventing secondary skin infections.
I can't leave skin problems without mentioning the single most important thing about skin disease. There is nothing that controls more skin disease than controlling fleas. Spending the money to use good flea control products limits skin disease and helps to prevent blood borne illnesses such as feline infectious anemia (Mycoplasma hemofelis infection). There are four effective flea prevention products, imidocloprid (Advantage tm), fipronil (Frontline, Frontline Topspot tm), selamectin (Revolution tm) and the combination of lufenuron ( Program tm) and nitenpyram Capstar (tm). There are no other substances, including garlic, brewer's yeast, used motor oil, Dawn (tm) dish detergent, permethrin, "flea dips" or anything else that work as well as these products. Keeping fleas under control is important. Use products that work.

Heart Disease
The major nutritional advances relating to heart disease can be summed up pretty quickly. Taurine is an amino acid that is essential to heart and eye health in cats. This is well known at this time so taurine is supplemented in most cat foods and nutritional deficiencies are rare. In dog breeds susceptible to dilated cardiomyopathy taurine and l-carnitine supplementation is sometimes helpful, especially in American cocker spaniels. Reduced intake of sodium (salt) is beneficial in congestive heart failure, although the degree of the benefits of low salt diets is controversial at this time. L-carnitine supplementation in boxers has a variable track record for treatment of dilated cardiomyopathy but it is pretty safe so it is frequently recommended.
There is no strong evidence for the use of a number of nutraceutical substances recommended for humans with heart disease, such as Coenzyme Q10, antioxidants or even the n3PUFAs in dogs and cats. This may be due to the differences in types of heart disease that occur in pets compared to humans, since the typical "heart attack" of humans is rare in dogs and cats. These products are pretty safe to use and veterinarians rarely argue strongly against trying them as long as purchase of the products isn't a financial burden for the client.
Digitalis from the foxglove plant is probably the best recognized herbal therapy for heart disease. It is inexpensive to buy digitalis or digoxin in purified forms at known dosages and the active ingredient is well known so using the herbal product isn't too common, though. There are also diuretic herbs but furosemide is very safe, works very well and is fairly inexpensive making the use of herbal diuretics as an alternative relatively uncommon.

Liver Disease
I am frequently frustrated by conversations with clients (and even family members) about the use of nutritional, herbal and homeopathic products to "cleanse" or "detoxify" the liver. These are completely meaningless terms from a functional standpoint. The liver is the major organ involved in removing toxins from the body. In some cases toxins, especially metals, do accumulate in the liver. However, for the most part, there is not a huge store of toxins residing in the liver at any time and there is no proof at all that the liver benefits from efforts to "cleanse" it or "detoxify" it. Maybe these are just marketing attempts at dumbing down the explanation of what may actually be happening in the liver but even so it is so misleading that it is truly annoying.
The liver does a number of complex tasks for the body. It is the major site for reassembly of digested proteins into the specific proteins needed by the body. It is also involved in the use of excess protein for energy and in processing other energy sources for the body. Stores of necessary nutrients such as glycogens can be found in the liver. With these and other tasks to do the liver has complex nutritional needs and may benefit from supplementation with nutraceuticals, herbal remedies or OTC antioxidants. It is very difficult to prove beyond doubt that a single supplement has long term benefits for the liver. For this reason, many of the recommendations made by experts in liver disease are based on theoretical effects of nutrients or other supplements rather than conclusive studies. It is important that this point is pretty clear. If you insist on a list of nutritional or pharmaceutical compounds proven by conclusive studies to be beneficial to the liver in pets over long periods of time it is easy to sum up what is available --- nothing. So when anyone advises you to give your pet a nutraceutical, OTC product or herbal remedy for liver disease you are forced to make the choice between products that may be beneficial based on theories that their mechanism of action would benefit the liver, , products shown to have some benefits in humans and/or products that people believe to be helpful based on observation of individual cases.
The supplement that meets both of the above criteria most closely is S-adenosylmethionine (SAMe). This is a nutraceutical product that is available under several brand names (Denosyl SD4, Zentonil Rx) and generically, as well. SAMe has a huge number of theoretical benefits as this compound influences many reactions in the liver and also provides an antioxidant effect. In people long term benefits in patients with cirrhosis of the liver have been demonstrated and it is likely that similar effects occur in pets. This product comes as a coated tablet or caplet and it is important not to break the coating prior to administration. While the recommended dosage is 10 to 20mg/kg the actual dosage has to be adjusted to fit the closest tablet size due to this requirement. SAMe is considered to be very safe to use so it is best to use the next largest tablet size in most cases rather than the lowering the dosage to get to a whole tablet dosage. The benefits of SAMe are thought to be numerous enough that it is recommended for almost all forms of liver disease. Pets who are on monoamine-oxidase inhibiting medications (MAOIs) should not be given SAMe.
The other nutrient that is frequently recommended for liver disease is Vitamin E supplementation. There are very specific reasons to use Vitamin E in copper and iron toxicosis cases and its antioxidant effects are thought to be beneficial in most other forms of liver disease. Vitamin E and SAMe supplementation are thought to be especially beneficial in cats with hepatic lipidosis.
Milk thistle ( Silybum marianum) and the extract from it, usually referred to as Silymarin, is the herb most commonly recommended for use in patients with liver disease. There are some studies that show specific benefits of this herb, especially in mushroom poisoning affecting the liver. In controlled studies in humans the expected benefits of Silymarin for long term control of liver disease have proven to be difficult to confirm. This herb seems pretty safe for dogs but due to its mechanism of action there is some question about safety in cats and in situations in which pets are on multiple medications.
Some researchers believe that supplementation of Coenzyme Q10 should be beneficial in pets with chronic liver disease or acute liver disease associated with oxidative injury, such as liver trauma or toxins. If this is the case it has not been proven definitively with scientific studies, however. Since Coenzyme Q10 seems very safe to take, it is likely that there would be no harm in trying it.
There are several herbs and herbal medications that are advocated for use in chronic liver disease. Of these the Chinese herbal remedy sho-saiko-to is the most widely studied in humans and it seems to have beneficial effects relating to reduction of oxidation injuries in chronic liver disease in humans. There are no supportive studies that I can find for the use of this combination in either dogs or cats but it is probably reasonable to assume that its use would be similar for dogs, at least. Cats are deficient in some liver enzymes and processes that are present in other species and a little more caution is advisable when using unstudied medications for liver disease in cats.
Supplementation of water soluble vitamins such as vitamin C and the B-complex vitamins is a good idea when liver disease is present, just to ensure that adequate vitamin supplies are present in the body. Whenever liver disease is causing enough toxin accumulation to provide clinical signs such as incoordination, confusion, seizures, vomiting or diarrhea it is helpful to use a diet that restricts total protein amounts while including very high quality protein sources to make it as easy as possible for the liver to do its job.
The one thing that is very important to understand about the use of nutraceuticals and herbal medications for chronic liver disease is that most studies show little benefit for any one of these types of medications but definite benefits when several are used together. Considering the number of jobs that the liver has to do it makes sense that it might take a number of different products to provide support for all the liver functions. So it makes more sense to use a multi-supplement approach, along with the appropriate prescription medications tailored to the specific problem. This can mean giving a pet multiple medications and supplements over the course of the day. This isn't always a conceivable option for pet owners who aren't home or who can't easily give pills to their pet. There is justification for using multiple supplements but you do have to consider the pet and the situation and make sure that you choose medications and supplements that you can continue to give long term on a regular basis as this is an important aspect of how they work.

Kidney Disease
Nutritional management of kidney disease is becoming more and more common in veterinary medicine. A good deal of this is due to the formulation of special commercial diets made for pets with kidney disease. It is important to remember that if the kidneys are affected, rather than the urinary bladder or lower urinary system, the diets should be designed to produce alkaline urine instead of acidic urine. Diets made to prevent cystitis and feline lower urinary tract disorders may not be good for the kidneys since they usually try to make the urine acidic. When kidney disease is present it is better if the urine is neutral but slightly basic is probably better than slightly acidic if a choice must be made.
The most important nutrient for cats and dogs with kidney failure is water. The more water intake that pets with kidney disease have, the better. It is helpful in older cats and dogs who are beginning to show signs of kidney failure to switch from dry dog or cat food to canned food, simply because it is about 80% water. Encourage water consumption by using flavored liquids if the pet likes them, providing a cat fountain for cats who like running water and keeping water available at all times. Adding water to the dog or cat food over and above what it already contains is another way to ensure additional water consumption.
Protein restriction as a method of slowing the progression of kidney failure in dogs and cats has been controversial for several years now. Using a very high quality protein in limited quantities was long thought to be beneficial in slowing progressive renal failure. At this time, it seems more likely that there is little to no benefit to protein restriction as a means of slowing kidney failure in either dogs or cats (although there are still some strong advocates of this approach in cats). Once kidney failure has progressed to the point that the BUN is greater than 60 to 80mg/dl it seems beneficial to use protein restriction to lower the BUN and to attempt to keep it below this level. The best advice seems to be to use the least amount of protein restriction that will achieve this result. This usually means mixing a protein restricted diet with a normal diet in varying proportions until it is possible to get the BUN below the 60mg/dl threshold.
Phosphorous restriction is beneficial for pets with chronic kidney failure. It is best to monitor the phosphorous levels in the serum and to adjust the use of diets low in phosphorous and/or the use of phosphate binding agents such as Ampogel (tm) to keep the phosphorous level below 6 mg/dl in the serum.
It is best to use a slightly salt restricted diet for pets with kidney failure. Potassium supplementation is beneficial for cats with chronic renal failure who have low potassium and some evidence suggests that it is helpful long before measurable drops in serum potassium occur. If metabolic acidosis occurs as chronic renal failure progresses it is reportedly possible to just to add sodium bicarbonate (baking soda) to a dog's water at dosages determined by your veterinarian based on the dog's need to correct the acidosis, without much resistance from the dog. I have to admit that I just read this bit of information in one of my nutrition books ( Canine and Feline Nutrition, Case, et.al.) and have not tried this approach in practice. This will also work for cats but it is probably better to use potassium citrate in cats due to the high incidence of potassium deficiency in cats with CRF.
The n3 PUFAs (n3 omega fatty acids) are thought to be beneficial in slowing renal failure in dogs and this may also be true for cats. This is also true for other antioxidant compounds such as Vitamin E, lycopene and SAMe. There may be some benefit to the use of carnitine supplementation once there is evidence of anemia associated with renal failure, based on studies in humans that have not been repeated in dogs or cats.
Herbal medications have not proven to be helpful in the treatment of kidney disease in dogs and cats when they have been examined in studies designed to measure effectiveness objectively. There are a large number of herbal supplements available and only about a dozen of these have been studied sufficiently to draw a conclusion so it is possible that in the future one or more herbal remedies or combinations of herbs may be shown to be beneficial. At this time, though, it is probably best to stick to nutritional management of kidney failure.

Footnotes:
Much of the information in this newsletter came from the Veterinary Clinics of North America, "Nutraceuticals and Other Biologic Therapies", Jan 04 and the Manual of Natural Veterinary Medicine, Wynn and Marsden.

The VetInfo Digest is published by:

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P.O. Box 476

Cobbs Creek, VA 23035.

The opinions expressed in this newsletter are those of Michael Richards, DVM., author.

To contact Dr. Richards use the email address mervet@inna.net. If there is a problem with the web site or you need help finding information that is already on the site, contact Michal Justis at vetinfo@vetinfo.com. Please remember that Dr. Richards can only answer questions for subscribers to the newsletter and www.vetinfo.com

This page was last edited 09/08/04
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