A B.C. naturopath's claim that she treated a small child's behaviour problems with a homeopathic remedy derived from rabid dog saliva has prompted a letter to the federal government from the province's senior public health official.

Provincial health officer Dr. Bonnie Henry said she will be writing to Health Canada to protest its approval of a treatment known as lyssinum after reading a blog post written by naturopath Anke Zimmermann of Victoria.

Henry wasn't aware of the substance before reading Zimmermann's post, but said she has already expressed concerns to the federal government about the regulation of homeopathic products.

"I will be writing to Health Canada about this preparation again," Henry told CBC News. "There's no way I can understand why we would have anything that was meant to be saliva of a rabid dog approved for use in this country."

Substance approved by Health Canada

Lyssinum, also known as lyssin or hydrophobinum, is one of more than 8,500 homeopathic products approved by Health Canada.

Homeopathy is based on the notion that "like cures like," and so-called nosodes like lyssinum are created by taking a bodily substance from a diseased human or animal and repeatedly diluting it in water and/or alcohol.

The case Zimmermann wrote about in February features a four-year-old boy who she says was aggressive and violent toward classmates, tended to hide under tables and growl, had trouble sleeping, and experienced nightmares about wolves and werewolves.

Zimmermann wrote that the boy improved dramatically after taking lyssinum, and she suspects the root of his problem was that he had been bitten by a dog.

"The way I see it, he is coming back into a more human state from a slightly rabid dog state," Zimmermann wrote.

Anke Zimmermann wrote about treating the boy in this February post to her website. (DrZimmermann.org)

Questions raised about therapeutic benefit

Henry said she had "grave concerns" about those claims and was not aware of any scientific evidence to support them.

"It's hard for me to believe as a physician that anything that was made from a very serious lethal infection … would have any therapeutic benefit," she said.

"I also have concerns that this would be used for treating what sounds very much like a behavioural issue in a young child."

Henry said she believes some homeopathic remedies can be helpful under certain circumstances, but not in this case.

"I have concerns that parents may want this type of treatment for their children, and delay accessing real treatments that may help them for some very severe conditions," she said.

Anke Zimmermann, a naturopath, in Victoria, said her four-year-old patient came into a 'more human state' from a 'slightly rabid dog state' after he was treated. (DrZimmermann.org)

But Zimmermann strongly objected to Henry's complaints.

"You can't have it both ways. You can't have homeopathy not working [and] be toxic," Zimmermann told CBC News.

"This child dramatically improved — the parents are very happy. Isn't that something that's interesting? Shouldn't we be looking into that?"

The saliva in the lyssinum she used to treat the little boy is diluted so many times that it wouldn't contain even a trace of the rabies virus, she added.

And she disputed claims that the treatment isn't scientifically proven.

"There's no common consensus about how the remedies work, but that they work is pretty clear. There are literally hundreds of millions of people around the world using homeopathy," Zimmermann said.

She has the support of the regulatory body for B.C.'s naturopathic doctors. According to the College of Naturopathic Physicians of British Columbia, lyssinum as an acceptable treatment.

"Homeopathy, which includes the use of substances such as lyssinum, is a traditional modality with a long history in the naturopathic scope of practice; it is still used by some naturopathic doctors today," deputy registrar Phillipa Stanaway wrote in an email.

Evidence 'clearly lacking'

But Henry isn't the only person expressing concerns about the treatment.

Stephen Hoption Cann, a professor in the School of Population & Public Health at the University of British Columbia, was alarmed by the claims made in Zimmermann's post.

"The clinical evidence for the utility of product derived from rabid dog saliva is clearly lacking," Hoption Cann wrote in an email.

"One of the concerns that stands out for me is that the naturopath implies the child might have contracted rabies and that the homeopathic product was the treatment. If a person, adult or child, actually contracts rabies and opts for this naturopathic remedy rather than the rabies vaccine, it could prove fatal."

University of Alberta professor Timothy Caulfield expressed serious concerns about Zimmermann's claims. (Monty Kruger/CBC)

Timothy Caulfield, Canada research chair in health law and policy at the University of Alberta, described Zimmermann's claims as "scientifically absurd."

"If this is a scientific profession, a fact-based profession, the regulators need to step up and try to control their members when they are saying things that are so patently absurd," he told CBC News.

Health Canada has not responded to a request for comment.