2013年9月24日星期二

Chamomile Tea for Arthritis in Dogs

I recently had a case which illustrates alternative therapies commonly present themselves in my daily practice. A patient, an older large breed dog, came in for an annual exam. He was in good general health but moderately overweight, and the only complaint was gradually progressive weakness in his hind legs. This is common in large older dogs and is often due to arthritis in the spine or hind legs. In this case, the patient had been diagnosed with a ruptured cranial cruciate ligament years before. At that time he was unable to use the leg and surgery had been recommended.


Surgery is the treatment of choice for a ruptured cruciate ligament. Weight loss, physical therapy, and possibly medications are all helpful and important, but without surgery a large dog will have permanent instability in the knee and will develop progressive arthritis. The acute pain of a recent ligament rupture will change to the nagging, chronic pain of degenerative joint disease, and the patient will learn to compensate for the disability, but the joint will not be fully functional or comfortable without repair.


There are a variety of surgical procedures available, and the evidence is not definitive as to which is the best, though most work well. Sometimes surgery is not possible because of the cost or other conditions the patient may have, but in this case surgery was not performed because of a misconception generated in part by the use of an alternative herbal remedy.


A veterinarian who practices primarily alternative therapies (mostly TCM and acupuncture but an assortment of others as well) had recommended Sleepytime herbal tea for treatment of the dog’s presumed arthritis. The main ingredient, chamomile flowers, is sometimes recommended for reducing anxiety, soothing an upset stomach or skin ailments, though like most herbal products one can find a recommendation for using it in dozens of unrelated conditions. It is reported to have anti-inflammatory properties and is one of a number of herbal ingredients in some products marketed for arthritis in dogs.


So what’s the evidence for using chamomile for arthritis? None that I can find. The Desktop Guide to Complementary and Alternative Medicine: An Evidence-Based Approach states:



There is little convincing evidence to support the therapeutic effectiveness of chamomile extracts. Encouraging evidence is emerging for a specific combination preparation in patients with functional dyspepsia. Given the risk of allergic reactions and the few rigorous clinical trials that have been conducted, it is not entirely clear whether the potential benefits outweigh the possible risks.



Neither this resource, nor PubMed, nor the Natural Medicine Comprehensive Database list any clinical trials in any species for chamomile as a treatment for arthritis. There are a couple of in vitro studies which suggest it might interfere with some enzymes that are involved in inflammation, but that is a far cry from proof of any clinical benefit in dogs with degenerative joint disease.


Are there any risks? Probably few. I happen to really like Sleepytime tea for the taste, and it has been a popular herbal tea for decades. It certainly is unlikely to be a significant health risk when brewed and drunk in the ordinary way. Severe allergic reactions to chamomile extracts have been reported in humans, but these are not apparently common, and there is no data on whether this is an issue for dogs.


So once again, the remedy itself is probably harmless and probably useless. Then what’s the problem? Well, the owners of this dog believed it helped their pet. The lameness gradually decreased over weeks to months of time, as it would be expected to do without any treatment at all. The owners took this as evidence the therapy was working and that surgery or real medical therapy was not needed. So now the dog has progressive arthritis and decreased use of one of its legs due to a lack of appropriate treatment for a very treatable problem. And this is largely because of the owners misperception and misplaced faith in a useless therapy. Such is often the way seemingly benign interventions like this can do harm.





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