A homeopathic physician in Canada used saliva from a dog with rabies to treat a boy who was having behavioral problems after contracting rabies himself.

A homeopathic practitioner in Canada has used a remedy containing diluted saliva from a dog infected with rabies to treat a young child with aggressive behavioral problems.

Dr. Anke Zimmermann, ND, a British Columbia-based naturopathic pediatrician who specializes in developmental and behavioral disorders, said the treatment was effective.

Rabies experts say she is barking up the wrong — and a potentially deadly — tree.

Zimmermann and other homeopathic practitioners say the “potentization,” or dilution of the remedies they use, eliminates any potential for disease transmission.

Such preparations may lack any trace of the source substance — one of several facts that causes mainstream healthcare experts to question their efficacy.

“Now it can’t be just water and toxic and full of live viruses at the same time, can it?” Zimmermann wrote in a blog post, where she asserted that homeopathic remedies “don’t contain any active viruses or other pathogens.”

“Mathematically speaking, these dilutions would be unlikely to contain an intact rabies virus,” Meghan A. May, PhD, a virologist and associate professor of microbiology and infectious diseases at the University of New England College of Osteopathic Medicine, told Healthline.

However, May said, dilution does not break down the rabies virus on a molecular level, so there’s a chance that even if a million doses contain nothing harmful, one could contain an intact, live virus.

“So you hope you don’t get that one,” she said.

Zimmermann detailed in a blog post — since amended — how she gave a homeopathic preparation marketed as Lyssinum to a 4-year-old child named Jacob. The boy was bitten by a dog at age 2.

His parents said he was hiding under a table and growling at classmates in his preschool.

“People who need Lyssin, also known as Hydrophobinum, are often afraid of the dark, of dogs, even of water, have trouble falling asleep, and are overly excitable,” wrote Zimmermann. “Aggression can also be a strong feature, as can dreams of dogs, wolves, and being attacked. This can even develop into full psychosis.”

Dr. William Shevin, a homeopathic practitioner based in Connecticut, told Healthline that Zimmermann’s use of Lyssin to treat a behavioral disorder marked by aggression “is really nothing unusual.”

“That remedy has been in use for a very long time,” Shevin, former president of the National Center for Homeopathy, told Healthline. “It was first used in 1833 and no one has ever gotten rabies from it.”

Zimmermann said the treatment yielded immediate results.

“Within a minute or two of giving him the remedy, Jonah smiled at me very broadly and beautifully, as if all the lights had just gone on,” she wrote.

Homeopathic physicians admit they have no clear idea what the “active ingredients” are in their remedies or how they work.

Some critics contend the remedies amount to little more than water.

“It’s not spectacularly clear to me what this kid was administered,” May said.

However, she noted: “Most people, if they’re bitten by a rabid animal, get a big dose of virus and start showing symptoms in a few months. But the longest case is about four years. So you may look at this child now and say he’s fine, but he’s really not out of the woods yet. There’s still a lot of watching to do and I think that’s terrifying.”

Homeopathy is based on the principle of “like treating like” — using highly diluted preparations containing a poison, substance, or bodily fluid believed to be related to the mental or physical condition of concern.

No credible study has ever found a homeopathic medicine to be more effective than a placebo.

Nonetheless, Health Canada lists many homeopathic remedies, called “nosodes,” as approved for use.

These include five versions of Lyssin, although not the type used by Zimmermann.

In the United States, homeopathic remedies are regulated by the Food and Drug Administration (FDA). However, the FDA does not evaluate such remedies for safety or effectiveness.

Zimmermann’s treatment tale has sparked concern from the British Columbia Naturopathic Association as well as officials with Health Canada.

The association filed a complaint against their fellow naturopathic physician over possible violations of the group’s code of conduct and code of ethics — stemming primarily from Zimmerman’s public statements, not her treatment methods.

Dr. Bonnie Henry, provincial health officer for the Province of British Columbia, issued a statement expressing concern that Lyssin could transmit rabies and called on Health Canada to review its approval of the homeopathic remedy.

Health Canada, in turn, launched an investigation into whether Zimmermann administered an unapproved version to her patient.

Zimmerman accused critics of fearmongering and being “completely uninformed” about homeopathic medicine.

She compared her treatment of rabies to a “vaccine after the fact” and said that, in the past, she has also prescribed Lyssin to patients who had an unreasonable fear of dogs.

That’s based on the theory that rabies is a disease of the central nervous system and, therefore, a rabies-based “nosode” can be effective in treating neurological or mental health issues.

“It can be a remedy for states of psychosis and frank insanity as the [rabies] infection in advanced stages causes just such a state,” she wrote.

May, who works at a school for osteopathic doctors, said, “There’s definitely a place for complementary and preventive medicine, but that’s quite different than homeopathy, which has treatments where nobody can actually say what’s in that vial you’ve been handed.”

She said that uncertainty is especially troublesome when the treatment is based on a live rabies virus.

“This is unfailingly a fatal disease and nothing to mess around with,” said May.