Startling evidence of the dangers to birds and rivers from over-the-counter drugs should be a wake-up call for owners to press for alternatives

When I was 10, I succeeded in my campaign for a family dog. Part of her care, and our joy as owners, was the monthly application of spot-on worm and flea treatment. With veterinary medicine on my mind as a career, I relished the theatre of vets-at-home. We bought doses over the counter, scheduling the dog’s treatment on the calendar like a five-a-side.

We applied these drugs to our dog because every other owner did. Because it was encouraged, because it was easy, because it felt right.

Sophie Pavelle is a writer and science communicator