UK and New Zealand scrutinise pet parasite treatments over environmental risks

Pet parasite treatments containing insecticides like fipronil and imidacloprid face increased scrutiny amid concerns over environmental and ecological risks, prompting calls for tighter controls and more research in both the UK and New Zealand.

Pet parasite treatments are facing renewed scrutiny after a UK parliamentary inquiry said their widespread preventive use is not backed by robust evidence and called for tighter controls on products containing insecticides already restricted in farming. According to reporting from the UK, the committee said chemicals such as fipronil and imidacloprid can pose risks to insects and aquatic life, and that more research is needed before routine use can be justified.

The issue is drawing attention in New Zealand too. Chloe McMenamin, a lecturer and researcher at Unitec, said over-the-counter sales of flea and tick products for routine monthly use are becoming harder to defend, and argued that regulators should consider veterinarian-led, risk-based treatment instead of blanket dosing. She said her team has found imidacloprid, fipronil and fluralaner in wastewater across the North Island, with levels likely to affect ecosystems.

Joanne Clapcott, president of the New Zealand Freshwater Sciences Society, said the immediate response should not be to discourage responsible parasite control, but to invest in monitoring and independent science. Melanie Kah of the University of Auckland said similar chemicals are tightly regulated in agriculture because of aquatic toxicity, yet those safeguards do not apply to pet medicines.

Veterinarian Siobhan Ellis said the products remain important for animal and human health, but agreed that more data are needed on environmental impacts, particularly between spot-on and oral formulations.