Over-the-counter flea treatment for cats and dogs should be banned as millions of hazardous chemicals are unnecessarily applied to UK pets each year, a parliamentary report has concluded.

Cats and dogs are widely treated with topical, or “spot on”, treatments that include insecticides to prevent fleas. Vets often recommend regular treatments as a preventive measure, even when the animals do not have fleas.

Two of the most frequently used chemicals in pet flea and tick treatments – imidacloprid and fipronil – are banned for use in pesticides in the EU and UK due to their severe toxicity to fish, invertebrates, bees and pollinators. By their very nature, these chemicals are designed to kill invertebrates at low doses.

A study found songbirds were using dog and cat fur contaminated with the treatments to create their nests. The scientists found a higher number of unhatched eggs or dead chicks in nests where there was a higher incidence of the chemicals.