Health Canada warns people not to take livestock dewormers

No evidence that drug is effective against COVID-19

File photo of a roundworm larva. (Dotana/iStock/Getty Images)

“Concerning reports” of people in Canada seeking out veterinary-grade dewormers for personal use have led Health Canada to formally advise against doing so.

News reports in Western Canada in the past week have described increased demand from non-farming consumers for veterinary-grade ivermectin, whether at livestock supply retailers or online.

While ivermectin is an antiparasitic drug — not an antiviral drug — the unusual demand is believed to be connected to unsubstantiated claims of the product as prevention or treatment against the COVID-19 virus in people.

As a result, Health Canada on Tuesday issued a formal advisory: “Do not use veterinary ivermectin for the prevention or treatment of COVID-19. If you have purchased ivermectin for this purpose, discard it immediately.”

While some formulations of the drug are registered in Canada for use against parasitic infections in people, Health Canada’s statement advises people not to use human-grade ivermectin against COVID-19 infection either.

“There is no evidence that ivermectin in either formulation is safe or effective when used for those purposes,” the department said.

Veterinary formulations are registered in Canada under brands such as Boehringer Ingelheim’s Ivomec and Vetoquinol’s Bovimectin, used against worms and lice in cattle; Bimeda’s Bimectin, used against parasites in cattle, horses, sheep and hogs; and Boehringer’s HeartGard, to treat heartworms and intestinal worms in dogs.

Provinces such as Alberta already require consumers to provide their farms’ premises ID numbers when buying any approved medicines and medicated items for use in livestock from authorized retailers. Some stores quoted in news reports have taken such products behind the counter and check for proof of livestock ownership.

Non-farming consumers who obtain veterinary drugs by other means “should never consume health products intended for animals because of the potential serious health dangers posed by them,” Health Canada said.

Veterinary ivermectin, which has more highly concentrated dosage than versions prescribed to people, may cause serious health problems such as “vomiting, diarrhea, low blood pressure, allergic reactions, dizziness, seizures, coma and even death,” the department said.

Health Canada, in its statement, cited a similar advisory from the U.S. Food and Drug Administration (FDA) citing “multiple reports of patients in the U.S. who have required medical support and been hospitalized after using ivermectin intended for horses.”

Health Canada said it’s “closely monitoring all potential therapeutic treatments for COVID-19, including treatments being studied in international clinical trials,” but has not received any drug submission or clinical trial application for ivermectin against COVID-19.

The department said it “will continue to monitor the situation and will take appropriate and timely action should new information become available, including any information regarding the illegal advertising or sale of ivermectin.”

The department added it has “previously warned Canadians about products making false and misleading claims to treat or cure COVID-19.”

Writing in May on an Ontario Veterinary College blog, OVC professor Dr. Scott Weese said ivermectin has been “widely discussed in some internet circles for treatment or prevention of COVID-19. That’s based on mainly anecdotes, some in vitro study, and very poor quality ‘clinical trials.’

“While conspiracy theories abound, no one has come up with any plausible explanation why an effective drug would be suppressed,” he added.

“Dexamethasone (a steroid used to treat patients with severe COVID-19) is cheap, widely used and widely produced, and it’s standard-of-care for some patients. That’s because it works. Ivermectin fits all of those except the ‘works for COVID-19’ which is the most important one.”

Furthermore, he wrote, ivermectin remains important for treatment of certain parasitic infections in people, and “diversion of the relatively small amount of human ivermectin products towards unnecessary use compromises the care of people that really need it.” — Glacier FarmMedia Network

About the author

Editor, Daily News

Dave Bedard

Editor of Daily News for the Glacier FarmMedia Network. A Saskatchewan transplant in Winnipeg.

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