A Calgary-based company, Solvet, has received emergency use authorization from the U.S. Food and Drug Administration (FDA) to sell its equine ivermectin product in the United States for combating screwworm. The CEO of Solvet, Lionel Gibbs, mentioned that their ivermectin liquid for horses is unique as it is aqueous-based, not a paste, making it more concentrated and easier to administer. Founded in 2009 by two former University of Calgary professors, Solvet has grown into one of Canada’s leading veterinary pharmaceutical companies.
Ivermectin, a well-known anti-parasitic drug, is commonly used to combat various parasites, including screwworm, a species of fly native to parts of North America. Screwworms pose a significant threat by laying eggs on open wounds of mammals, such as horses, cattle, and occasionally humans, leading to severe pain, infections, and potential death. The successful eradication of screwworm from North America in the past was achieved through the sterile insect technique, where mass-produced sterile male flies were released to disrupt the breeding cycle of the flies.
However, screwworm has recently reappeared in North America, starting in Central America and moving northward, causing concern in the southern United States. Following the discovery of screwworm larvae on a calf in Texas in June 2026, the Canadian Food Inspection Agency (CFIA) implemented a temporary ban on imports of animals from Texas to prevent the spread of the pest.
The FDA’s emergency authorization of Solvet’s ivermectin liquid specifically for screwworm in horses aims to address the risk posed by the parasite. According to John Gilleard, a veterinarian and parasitologist at the University of Calgary, the authorization helps protect animals from severe tissue damage caused by screwworm larvae. While the product is authorized for short-term prevention when administered soon after birth or during initial wound care, the challenge lies in ensuring responsible use to prevent resistance in parasites and minimize environmental impacts.
Despite the low risk of screwworm in Canada due to the unsuitable climate for the flies, the CFIA continues to monitor the situation closely and collaborate with U.S. authorities. Solvet sees this opportunity not only as a way to enhance animal welfare but also as a stepping stone for expansion into the U.S. market, potentially benefiting Alberta’s economy and research initiatives.