Overtoun Bridge

Overtoun Bridge is a category B-listed structure over the Overtoun Burn on the approach road to Overtoun House, near Dumbarton in West Dunbartonshire, Scotland.

Completed in 1895 to a design by the civil engineer H. E. Milner, the bridge has attracted international media attention because of the number of dogs who have reportedly leapt to their deaths from it, killed on the rocks 50 feet (15 m) below.

Lord Overtoun had inherited Overtoun House and the estate in 1891. He purchased the neighbouring Garshake estate to the west of his lands in 1892. Carriages had been unable to gain access to the Overtoun mansion along the old eastern approach road as the incline was too steep; work commenced on constructing a new driveway as soon as Garshake was acquired.

Designed by the civil engineer H. E. Milner, the bridge is constructed from rough-faced ashlar and was completed in June 1895. It comprises three arches: a large central arch spanning a deep valley at the bottom of which flows the Overtoun Burn, flanked on each side by lower, smaller pedestrian arches.

Studies have shown that since the 1950s or 1960s numerous dogs have leaped from the bridge at the rate of about one per year. Dogs that leap over the bridge parapet fall 50 feet (15 m) onto the waterfalls below. The only linking factors for this unexplained event are that dogs mostly jump from the same side of the bridge, in clear weather, and they are breeds with long snouts.

As the unexplained phenomenon received international media attention, the Royal Society for the Protection of Birds sent an animal habitat expert, David Sexton, to investigate the causes as to why dogs kill themselves at Overtoun Bridge. Initially canine psychologist Dr. David Sands examined sight, smell and sound factors. After eliminating what a dog could potentially see and hear on the bridge, Sexton eventually focused on scent following the discovery of mice and mink in undergrowth on the side of the bridge from which dogs often leaped, and squirrels in the structure. In a test, the odours from these animals were spread around an open field. Ten dogs were unleashed, representing the most common breeds that jumped off the bridge. Of the dogs tested, only two showed no interest in any of the scents while seven others made straight for the mink scent. Sands concluded that, although it was not a definitive answer, the potent odour from male mink urine was possibly luring keen-nosed dogs to their deaths. However, a local hunter, John Joyce, who has lived in the area for 50 years, said in 2014, "[T]here is no mink around here. I can tell you that with absolute certainty."

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