In the last post, I focused on really looking at the source of the information you are receiving about your dog’s cancer. Let’s get into some specific examples of questionable “intelligence” you may have received.
Some, claiming authority in the area of supplements for dog cancer, are pushing Pau D’Arco. Be careful, everyone!
Let’s look at Pau D’Arco. This is the common name for a tea, capsule, liquid extract, salve or tablet from Tabebuia impetiginosa, a tree common in South America, especially Brazil. The bark is used for these medicinal preparations.
Pau D’Arco does have a lot of postive test-tube (“in vitro”) effects on cancer cells. Unfortunately, lots and lots of compounds kill cancer cells in test tubes. The clinical trials in people (“in vivo”, or in living bodies) have been mixed, with the most well-designed one (“Early Clinical Studies With Lapachol”) yielding little benefit.
The American Cancer Society does not like Pau D’Arco for use in people due to safety concerns. One could make the claim that they are just part of the “machine” trying to keep miracle cures suppressed to aid Big Pharma.
Whatever your belief is, and few people could deny the force of Big Pharma’s strategic influence, the concern over safety and effectiveness is well-founded at this point.
What is the evidence?
Well, lapachol, an active component Pau D’Arco, is toxic to developing embryos in pregnant lab animals. It also messes up fertility of male lab rats. Okay, granted, most chemotherapy agents have similar effects, so Pau D’Arco cannot be tossed out on this basis alone. It should never be used in breeding animals, obviously.
At oral doses necessary for required concentrations around cancer cells, Pau D’Arco caused vomiting, blood clotting problems, and diarrhea. Well, these are not good either, but one could also state these side effects are seen with chemo too, and that would be a valid point. Of course, it is no-brainer to state that Pau D’Arco should never be used before surgery, during wound healing, in animals with blood clotting problems, or with tumors that could bleed.
Pau D’Arco has hydroquinone in it. This is bad stuff. Not only is it carcinogenic (irony of all ironies), but it is toxic to vital organs too. Read all about it here. Well, again, the same could be said of some of our common chemo drugs.
So what really makes Pau D’Arco dicey? One thing that is quite bothersome is a lack of batch standardization. Not only do the lapachol and other components vary from tree to tree, but sometimes they are actually absent.
On top of that, sometimes the the trees from which the bark is taken are from different Tabebuia species. The tree appears to be getting more scarce due to it’s reputation, and we are getting herbal preparations containing the wrong bark.
Finally, chemo drugs are used under strict veterinary supervision. Pau D’Arco usually is not. Both have real side effect concerns. Substances with these possible adverse health effects should not be used by a layperson without supervision.
There is no doubt that Pau D’Arco should be studied more or used as a template for new drugs, since the active compounds in the bark may have merit. However, since it contains some things that could, from time to time, pose real health hazards, and the batches vary in composition (does your dog’s batch have a lot of hydroquinone???), it is a gamble that I cannot take with dogs I care about.
Please be careful of what you read!
For more information on herbs or supplements for dogs with cancer, check out The Dog Cancer Survival Guide.
Best to all,
Dr. Demian Dressler is internationally recognized as “the dog cancer vet” because of his innovations in the field of dog cancer management, and the popularity of his blog here at Dog Cancer Blog. The owner of South Shore Veterinary Care, a full-service veterinary hospital in Maui, Hawaii, Dr. Dressler studied Animal Physiology and received a Bachelor of Science degree from the University of California at Davis before earning his Doctorate in Veterinary Medicine from Cornell University. After practicing at Killewald Animal Hospital in Amherst, New York, he returned to his home state, Hawaii, to practice at the East Honolulu Pet Hospital before heading home to Maui to open his own hospital. Dr. Dressler consults both dog lovers and veterinary professionals, and is sought after as a speaker on topics ranging from the links between lifestyle choices and disease, nutrition and cancer, and animal ethics. His television appearances include “Ask the Vet” segments on local news programs. He is the author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity. He is a member of the American Veterinary Medical Association, the Hawaii Veterinary Medical Association, the American Association of Avian Veterinarians, the National Animal Supplement Council and CORE (Comparative Orthopedic Research Evaluation). He is also an advisory board member for Pacific Primate Sanctuary.