Deadly Parasites? Researchers Warn of Rising Drug Resistance in Dog Hookworms

New research reveals that canine hookworms in Australia are developing growing resistance to drugs.

New research indicates that canine hookworms in Australia are increasingly resistant to commonly used drugs, posing a growing challenge for pet health.

Researchers from The University of Queensland (UQ) and The University of Sydney have found extensive resistance to benzimidazole-based dewormers, which are widely used to treat gastrointestinal parasites in dogs.

Dr. Swaid Abdullah from UQ’s School of Veterinary Science reported that nearly 70% of the hookworm samples analyzed carried genetic mutations associated with drug resistance.

Risks to Human Health

“This is a big problem, as hookworm infections can be dangerous for both humans and animals,” Dr Abdullah said. “In dogs, hookworm infections primarily affect the small intestine leading to anemia, diarrhea, and malnutrition. But worse still, the parasites can spread to humans through the skin. In people, hookworms from dogs can cause cutaneous larva migrans (CLM) disease – or ‘creeping eruption’ – which is a winding, snake-like rash with blisters and itching.”

Dr Abdullah said the best weapons against canine hookworms have been benzimidazole-based dewormers, but they are starting to fail.

“This level of resistance is an urgent issue for pet and public health,” he said.

The study team used advanced parasitological diagnostics to examine samples from more than 100 animals in Australia and New Zealand.

The results showed resistance was spreading through hookworm species including the northern hookworm, which had previously been thought to be unaffected.

The Need for Targeted Treatment

Professor Jan Šlapeta from The University of Sydney said routine reliance on deworming drugs is likely fuelling the development of resistance

“Responsible parasite management by veterinarians is going to be vital moving forward,” Professor Šlapeta said. “We’re calling for a shift toward targeted, risk-based treatment to curb the spread of resistant hookworm. Responsible doctors don’t give blanket antibiotics to any and all of their patients, and deworming should be approached in the same way if we’re to limit drug resistance.”

He continues, “As resistance spreads, we need ongoing monitoring and the development of new control strategies to protect animal and human health. This study is a wake-up call for both pet owners and veterinarians alike – the era of effortless parasite control may be coming to an end.”

Reference: “Widespread occurrence of benzimidazole resistance single nucleotide polymorphisms in the canine hookworm, Ancylostoma caninum, in Australia” by Swaid Abdullah, Thomas Stocker, Hyungsuk Kang, Ian Scott, Douglas Hayward, Susan Jaensch, Michael P. Ward, Malcolm K. Jones, Andrew C. Kotze and Jan Šlapeta, 22 December 2024, International Journal for Parasitology.
DOI: 10.1016/j.ijpara.2024.12.001