Many owners administer herbal supplements to their pets with cancer with the hope that these alternative therapies will afford their pet a therapeutic edge in fighting the disease.

 

The amount of information suggesting the beneficial effects of various herbs, anti-oxidants, “immune boosting treatments,” and dietary supplements is astounding. The appeal of using a substance that is “natural” and “non-toxic” to disease is inarguably real.

 

What most owners fail to recognize is that herbal medications are not subject to the same regulations by the Food and Drug Administration (FDA) that prescription drugs are. Owners are also unaware that carefully worded claims to efficacy are not backed up by scientific research in the vast majority of cases, despite the plethora of supportive material listed on product inserts or on websites.

 

Legally, herbal supplements are considered “foods” and not “drugs.” Therefore, the FDA has minimal regulatory role over their production and advertising.

 

The FDA acts to ensure that there are no overtly misleading claims made by the manufacturer, and also mandates that it is illegal for a product sold as a dietary supplement to be promoted on its label, or in any of its labeling material, as a “treatment, prevention, or cure for a specific disease or condition.”

 

Dietary supplements do not need approval from the FDA before they are marketed. Except in the case of a new dietary ingredient, where pre-market review for safety data and other information is required by law, a firm does not have to provide the FDA with the evidence it relies on to substantiate safety or effectiveness before or after it markets its products.

 

A recent investigation was conducted by the New York State Attorney General’s office examining the integrity of various herbal supplements via DNA analysis of their ingredients. Results astonishingly showed that 4 out of 5 herbal products were found to contain none of the herbs listed on the ingredient label.

 

From the press release from the New York State Attorney General’s office:

 

Overall, just 21% of the test results from store brand herbal supplements verified DNA from the plants listed on the products’ labels — with 79% coming up empty for DNA related to the labeled content or verifying contamination with other plant material.

 

… 35% of the product tests identified DNA barcodes from plant species not listed on the labels, representing contaminants and fillers. A large number of the tests did not reveal any DNA from a botanical substance of any kind. Some of the contaminants identified include rice, beans, pine, citrus, asparagus, primrose, wheat, houseplant, wild carrot, and others. In many cases, unlisted contaminants were the only plant material found in the product samples.

Though the results of the investigation are concerning, one could argue a lack of accuracy in product integrity would do little harm other than waste the buyer’s money.  As a veterinarian, what I worry about is whether what’s actually present in the supplement could be detrimental to my patient’s health.

 

Could these non-listed ingredients cause a severe allergic reaction in an animal? Could these additional ingredients interact negatively with a previously prescribed conventional treatment? Are they really safe?

 

I’m not arguing against using natural substances to treat disease. In fact, one of the most common chemotherapy drugs I prescribe is vincristine, a drug derived from the periwinkle plant. Aspirin was originally produced from salicylate containing plants such as the willow tree. And on a personal account, ginger is a definite anti-nausea remedy for my own occasionally sour stomach.

But I also know that many natural substances can be extremely toxic for pets. There are many species of poisonous wild mushrooms; botulin toxin (aka “Botox”) is natural, but can be deadly for animals; and yes, even the vincristine I prescribe routinely to my patients can be deadly if proper dosing is not maintained.

 

I’m concerned that owners are wasting their money on supplements touted as cure-alls for their pets. I worry that these substances could actually be causing harm to my patients because of unknown ingredients that interact negatively with prescribed medications or with that animal’s particular physiological constitution. And I have concerns that the average consumer isn’t aware of the lack of regulation of these substances, which is the impetus for writing this article. 

 

Be sure to speak directly with your veterinarian in reference to your questions about supplements and their potential role in your pet’s healthcare. And be sure to let your pet’s doctor know about any supplements, vitamins, and other over the counter remedies you may be administering to your pet. An open dialogue is essential for making the best decisions about your furry companion’s well being.

 

To learn more, visit the American Cancer Society’s information page on supplements: Dietary Supplements: What is Safe?

 

 

Dr. Joanne Intile

 

 

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