Since there has been so much discussion lately about colloidal silver, I would like to post for general information a veterinary advice column devoted to the subject appearing in the new just-out issue of the Independent Voice, written by Virginia ferret specialist Dr. Jean Wardell, who has worked with Dr. Tom Kawasaki. Q. There has been a lot of hype recently about the use of colloidal silver as a cure for "the greenies." What is it? Is it safe? Does it really work? A. I have had several requests for information about this compound. From what I understand, it is being hailed as an apparent cure for epizootic catarrhal enteritis or ECE, aka green virus diarrhea in ferrets. A brief history and some background information about colloidal silver is appropriate. This compound was first introduced in the late 1800s as a panacea with claims of being able to prevent and treat a variety of maladies including tonsillitis and cancer. Since it was first marketed before 1938, it is treated as exempt from the FDA Act, which requires that all drugs marketed after that year have concrete evidence attesting to their safety and efficacy. The only stipulations are that they be advertised and labeled for the same uses as they were before 1938, and that they be manufactured in the "original manner" (whatever that may be). However, the FDA does not have any scientific evidence which supports the claim of oral colloidal silver solutions being useful in preventing or treating any serious disease conditions. Furthermore, the FDA has not approved a new drug application for colloidal silver. In 1994, a number of companies were issued warning letters for promoting the use of oral colloidal silver as treatment for an unbelievable and extensive list of health conditions that included HIV/AIDS, staph and strep infections, diabetes, pneumonia, syphilis, and herpes. These claims are fraudulent and deceiving. Products containing this compound are being used to treat conditions that require a professional rather than lay-person diagnosis. It is not possible for colloidal silver products to be used with a guarantee of safety and efficacy. Let's turn now to the question of the biological safety of such products. Unfortunately, to date all the research, statistics, and studies have been done on humans. There is nothing available specifically addressing the safety in animals. The Office of OTC (over the counter) Drug Evaluation has the results of a chemical assay report from the Dallas Regional Pesticide Laboratory. It was concluded that the amount of silver present in the product was too low to result in toxicity in humans at the recommended dose of one teaspoon per day. The daily dose of oral colloidal silver currently being recommended by some advocates is up to 2.5 cc per ferret. Assuming the average adult weighs 150 pounds and is taking 1 teaspoon per day, a 2-lb ferret would require about .01 teaspoon or .05 cc. A ferret receiving 2 cc of colloidal silver would, using simple proportional arithmetic, be ingesting about 40 times the recommended oral dose in humans. [Moderator's note: Huh? By my math 2.5cc in 150# human works out closer to .03cc, not .05cc. BIG] It must be understood that over 90% of orally ingested silver is not absorbed, and the liver's biliary system actively excretes it. One of the associated conditions of ECE in ferrets is hepatitis... liver inflammation disease. This inherently implies that liver function is reduced. It may be theoretically possible for ferrets with ECE that are treated with colloidal silver to develop toxicity due to their small size and impaired ability to excrete the elemental silver. Indiscriminate and improper use may also result in the development of a condition known as argyria (which has been documented in people). This is an irreversible discoloration of the skin, conjunctiva, and internal organs that occurs when silver salts are used over a period of time. Unfortunately, the exact time frame which constitutes "a period" has not been quantified. I cringe when considering the potential effects, both short and long term, that such products may have when administered to ferrets. What is the dose? What is the frequency of administration? In what form should it be administered? What are the side effects? What are the implications in ferrets that are already battling hepatitis secondary to the greenies? These and other important questions remain unanswered. As we are all well aware, ECE causes a constellation of clinical symptoms in the ferret. In the more severe cases, the typical green diarrhea is accompanied by lethargy, depression, anorexia, weight loss, gastric ulcers, hepatitis, and dehydration. These are entities which need to be individually addressed. I worry about and do not advocate the use of colloidal silver products in such a small, delicate species about which we know very little to begin with... to say nothing of how little we know about the manner that some antiquated heavy metal-containing agent of supposed therapeutic value affects them. A veterinarian experienced with ferrets should tailor the medical protocol of management for ferrets with ECE. Leave the silver for the jewelers and industrialists. [Moderator's note: I'm trying hard to hold my tounge here - there's lots to be said on both sides of the issue. Comments welcome. BIG] [Posted in FML issue 1369]