Ecologists fight the rise of tough, toxic cowpats

Scientists will gather in the French Alps at the weekend to discuss the complex problem of the poisonous and ever-lasting cowpat.

Scientists will gather in the French Alps at the weekend to discuss the complex problem of the poisonous and ever-lasting cowpat.

A medicine given to cows, sheep and horses before they go to summer pasture in the Alps has made their dung toxic and virtually indestructible.

Insects that normally feed on the droppings are dying in numbers, threatening the survival of birds and bats that eat the insects. A single cowpat left by an animal treated with the medicine is estimated to be capable of killing up to 20,000 dung-eating insects a week.

Professor Jean-Pierre Lumaret, from the University of Montpellier, an expert on the ecology of Alpine meadows, said: "A cow produces about 12 cowpats a day. If the dung does not decompose, it becomes like stone, which stops the grass from growing. In the Mediterranean area, we have seen cowpats [from treated animals] survive for four years or more."

Cowpats from a herd of 100 cows add up to a lot of toxic dung over four years. They would eventually ruin a pasture, not only for insects, but also for cows, Professor Lumaret said.

The cause of the problem is believed to be a medicine called ivermectine, which is inserted in the form of a "bolus" or blob in the throat of the animal when it is sent to the high Alpine meadows for the summer. Small amounts of the medicine released daily protect the animals from parasites.

The aim of this weekend's conference, part of an "ecological fair" at Albenc in Isère, south-east France, is to persuade farmers and vets to use another kind of treatment.